Komatsu SK714-5, SK815-5, SK815-5 turbo Service Manual

WEBM005500

WEBM005500

SK714-5 SK815-5 SK815-5 turbo

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CONTENTS

CONTENTS

Page

10 STRUCTURE AND FUNCTION........................................................................................10-1

20 TESTING AND ADJUSTING.............................................................................................20-1

30 DISASSEMBLY AND ASSEMBLY..................................................................................30-1

40 MAINTENANCE STANDARD...........................................................................................40-1

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SK714-5 SK815-5 SK815-5 turbo

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SK714-5 SK815-5 SK815-5 turbo

IMPORTANT SAFETY NOTICE

Proper service and repair is extremely important for the safe operation of your machine.
The service and repair techniques recommended by Komatsu Utility and describe in this manual are both ef­fective and safe methods of operation. Some of these operations require the use of tools specially designed
by Komatsu Utility for the purpose.
To prevent injury to workers, the symbols and are used to mark safety precautions in this manual.
The cautions accompanying these symbols should always be carefully followed. If any danger arises or may
possibly arise, first consider safety, and take necessary steps to face.

SAFETY

GENERAL PRECAUTIONS

Mistakes in operation extremely dangerous.
Read all the Operation and Maintenance Manual care­fully BEFORE operating the machine.

1. Before carrying out any greasing or repairs, read all
the precautions written on the decals which are suck
on the machine.

2. When carrying out any operation, always wear safe­ty shoes and helmet. Do not wear loose work
clothes, or clothes with buttons missing.

• Always wear safety glasses when hitting parts

with a hammer.

• Always wear safety glasses when grinding

parts with a grinder, etc.

3. If welding repairs are needed, always have a
trained, experienced welder carry out the work.
When carrying out welding work, always wear weld­ing gloves, apron, glasses, cap and other clo thes
suited for welding work.

4. When carrying out any operation with two or more
workers, always agree on the operating procedure
before starting. Always inform your fellow workers
before starting any step of the operation. Before
starting work, hang UNDER REPAIR signs on the
controls in the operator’s compartment.

5. Keep all tools in good condition and learn the correct
way to use them.

6. Decide a place in the repair workshop to keep tools
and removed parts. Always keep the tools and parts
in their correct places. Always keep the work are a
clean and make sure that there is no dirt or oil on the
floor.
Smoke only in the areas provided for smoking. Nev­er smoke while working.

PREPARATIONS FOR WORK

7. Before adding or making any repairs, park the ma­chine on hard, level ground, and block the wheels to
prevent the machine from moving.

8. Before starting work, lower outrigger, bucket or any
other work equipment to the ground. If this is not
possible, use blocks to prevent the work equipment
from falling down. In addition, be sure to lock all the
control levers and hang warning sign on them.

9. When disassembling or assembling, support the
machine with blocks, jacks or stands before starting
work.

10. Remove all mud and oil from the steps or other plac­es used to get on and off the machine. Always use
the handrails, ladders or steps when getting on or off
the machine.
Never jump on or off the machine.
If it is impossible to use the handrails, ladders or
steps, use a stand to provide safe footing.

PRECAUTIONS DURING WORK

11. When removing the oil filler cap, drain plug or hy­draulic pressure measuring plugs, loosen them
slowly to prevent the oil from spurting out.
Before disconnecting or removing components of
the hydraulic circuit and engine cooling circuit, first
remove the pressure completely from the circuit.

12. The water and oil in the circuits are not hot when the
engine in stopped, so be careful not to get burned.
Wait for the oil water to cool before carrying out any
work on the cooling water circuits.

13. Before starting work, remove the leads from the bat­tery. Always remove the lead from the negative ( – )
terminal first.

SAFETY

SK714-5 SK815-5 SK815-5 turbo

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SAFETY

14. When raising heavy components, use a hoist or
crane. Check that the wire rope, chains and hooks
are free from damage.
Always use lifting equipment which has ample ca ­pacity. Install the lifting equipment at the correct
places.
Use a hoist or crane and operate slowly to prevent
the component from hitting any other part.
Do not work with any part still raised by the hoist or
crane.

15. When removing covers which are under internal
pressure or under pressure from a spring, always
leave two bolts in position on opposite sides. Slowly
release the pressure, then slowly loosen the bolts to
remove.

16. When removing components, be careful not to
break or damage the wiring.
Damage wiring may cause electrical fires.

17. When removing piping, stop the fuel or oil from spill­ing out. If any fuel or oil drips on to the floor, wipe it up
immediately.
Fuel or oil on the floor can cause you to slip, or can
even start fires.

18. As a general rule, do not use gasoline to wash parts.
In particular, use only the minimum of gasoline
when washing electrical parts.

19. Be sure to assemble all parts again in their original
places. Replace any damage parts with new parts.
When installing hoses and wires, be sure that they
will not be damaged by contact with other parts
when the machine is being operated.

20. When installing high pressure hoses, make sure
that they are not twisted. Damaged tubes are dan­gerous, so be extremely careful when installing
tubes for high pressure circuits. Also, check that
connecting parts are correctly tightened.

21. When assembling or installing parts, always use
specified tightening torques.
When installing the parts which vibrate violently or
rotate at high speed, be particulary careful to check
that they are correctly installed.

22. When aligning two holes, never insert your fingers
or hand.

23. When measuring hydraulic pressure, check that the
measuring tool is correctly assembled before taking
any measurement.

24. Take sure when removing or installing wheels.

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SK714-5 SK815-5 SK815-5 turbo

FOREWORD

FOREWORD

This shop manual has been prepared as an aid to improve the quality of repairs by giving the operator an accurate
understanding of the product and by showing him the correct way to perform repairs and make judgements. Make sure
you understand the contents of this manual and use it to full effect at every opportunity.

This shop manual mainly contains the necessary technical information for operations performed in a service work­shop.

The manual is divided into chapters on each main group of components; these chapters are further divided into the
following sections.

STRUCTURE AND FUNCTION

This section explains the structure and function of each component. It serves not only to give an u nderstanding
of the structure, but also serves as reference material for troubleshooting.

TESTING AND ADJUSTING

This sections explains checks to be made before and after performing repairs, as well as adjustments to be
made at completion of the checks and repairs.
Troubleshooting charts correlating «Problems» to «Causes» are also included in this section.

DISASSEMBLY AND ASSEMBLY

This section explains the order to be followed when removing, installing, disassembling or assembling each
component, as well as precautions to be taken for these operations.

MAINTENANCE STANDARD

This section gives the judgement standards when inspecting disassembled parts.

NOTE

The specifications contained in this shop manual are subject to change at any time and without any no­tice.
Contact your Komatsu Utility distributor for the latest information.

SK714-5 SK815-5 SK815-5 turbo

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HOW TO READ THE SHOP MANUAL

HOW TO READ THE SHOP MANUAL

VOLUMES

Shop manual are issued as a guide to carry out repairs.
These various volumes are designed to avoid duplicat­ing the same information.

DISTRIBUTION AND UPDATING

Any additions, amendments or other changes will be
sent to Komatsu Utility distributors.
Get the most up-to-date information before you start any
work.

FILING METHOD

1. See the page number on the bottom of the page.
File the pages in correct order.

2. Following examples show you how to read the page
number.
Example:

10

-

3

Item number (10. Structure and
Function)

Consecutive page number for each
item

SYMBOLS

In order to make the shop manual greatly chelpful, im­portant points about safety and q uality are marked with
the following symbols.

Symbol Item Remarks

Special safety precautions
are necessary when
performing the work.

★

Safety

Caution

Weight

Tightening

torque

Extra special safety precautions
are necessary when performing
the work because it is under in­ternal pressure.

Special technical precautions or
other precautions for preserving
standards are necessary when
performing the work.

Weight of parts or systems.
Caution necessary when select­ing hoisting wire, or when work­ing posture is important, etc.

Parts that require special atten­tion for the tightening torque dur­ing assembly.

3. Additional pages: additional pages are indicated by
a hyphen (–) and number after the page number.
Fle as in the example.
Example:

10-4

10-4-1

Added pages

10-4-2

10-5

REVISED EDITION MARK
(

➀ ➁ ➂ ....)

When a manual is revised, an edition mark is recorded
on the bottom outside corner of the pages.

REVISIONS

Revised pages are shown on the LIST OF REVISED
PAGES between the title page and SAFETY page.

Coat

Oil, water

Drain

Parts to be coated with adhe­sives and lubricants etc.

Places where oil, water or fuel
must be added, and their quan­tity.

Places where oil or water must
be drained, and quantity to be
drained.

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SK714-5 SK815-5 SK815-5 turbo

HOISTING INSTRUCTIONS

Heavy parts (25 kg or more) must be lifted

with a hoist etc. In the

bly

section, every part weighing 25 kg or more is

clearly indicated with the symbol

1. If a part cannot be smoothly removed from the ma­chine by hoisting, the following checks should be
made:

• Check for removal of all bolts fastening the part

to the relative parts.

• Check for any part causing interference with

the part to be removed.

2. Wire ropes

1) Use adequate ropes depending on the weight of

parts to be hoisted, referring to the table below:

(Standard «S» or «Z» twist ropes

without galvanizing)

Rope diameter (mm) Allowable load (tons)

10.0

11.2

12.5

14.0

16.0

18.0

Disassembly and Assem-

WIRE ROPES

1.0

1.4

1.6

2.2

2.8

3.6

HOISTING INSTRUCTIONS

Hooks have maximum strength at the middle por­tion.

3) Do not sling a heavy load with one rope alone, but
sling with two or more ropes symmetrically wound
on to the load.

Slinging with one rope may cause turning of the load
during hoisting, untwisting of the rope, or slipping of
the rope from its original winding position on the
load, which can cause dangerous accidents.

4) Do not sling a heavy load with ropes forming a wide
hanging angle from the hook.
When hoisting a load with two or more ropes, the
force subjected to each rope will increase with the
hanging angles.
The table below shows the va riation of a llowable
load (kg) when hoisting is made with two ropes,
each of which is allowed to sling up to 1000 kg ver­tically, at various handing angles.
When two ropes sling a load vertically, up to 2000 kg
of total weight can be suspended.
This weight becomes 1000 kg when two ropes
make a 120° hanging angle.
On the other hand, two ropes are subjected to an ex­cessive force as large as 4000 kg if they sling a 2000
kg load at a lifting angle of 150°.

20.0

22.4

30.0

40.0

50.0

60.0

The allowable load value is estimated to be one­sixth or one-seventh of the breaking strength of the
rope used.

2) Sling wire ropes from the middle portion of the hook.
Slinging near the edge of the hook may cause the
rope to slip off the hook during hoist
rious accident can result.

4.4

5.6

10.0

18.0

28.0

40.0

ing, and a se-

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STANDARD TIGHTENING TORQUE

The following charts give the standard tightening torques of bolts and nuts.
Exceptions are given in section of «Disassembly and Assembly».

1. STANDARD TIGHTENING TORQUE OF BOLTS AND NUT

Width across flat

Thread

diameter of bolts

(mm)

Pitch of

bolts

(mm)

(mm)

kgmNmkgmNm

STANDARD TIGHTENING TORQUE

10

12

14

16

18

20

22

24

27

30

6

8

1

1.25

1.5

1.75

2

2

2.5

2.5

2.5

3

3

3.5

10

13

17

19

22

24

27

30

32

36

41

46

8

6

8

10

12

14

14

17

17

19

19

22

0.96

2.3

4.6

7.8

12.5

19.5

27

38

52

66

96±10

131

±0.1

±0.2

±0.5

±0.8

±1
±2

±3

±4

±6

±7

±14

9.5

23

45

77

122

191

262

372

511

644

945

1287

±1

±2

±4.9

±8

±13
±21

±28

±40

±57

±70

±100

±140

1.3

3.2

6.5

17.5

92

135

184

±0.15

±0.3

±0.6

11

27

37

53

73

±10

±1

±2
±3

±4

±6

±8

±15

±20

13.5

32.2

63

108

172

268

366

524

719

905

1329

1810

±1.5

±3.5

±6.5

±11

±18
±29

±36

±57

±80

±98

±140

±190

33

36

39

This torque table does not apply to bolts or nuts which have to fasten nylon or other parts non-ferrous metal washer.

3.5

4

4

50

55

60

24

27

----

177

±20

230±25

295

±33

1740

±200

2250±250

2900

±330

250

±27

320±35

410

±45

2455

±270

3150±350

4050

±450

★ Nm (newton meter): 1 Nm = 0.102 kgm

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SK714-5 SK815-5 SK815-5 turbo

2. TIGHTENING TORQUE FOR NUTS OF FLARED

Use these torques for nut part of flared.

STANDARD TIGHTENING TORQUE

Thread diameter

of nut part

(mm)

1/2” - 20

9/16” - 18

3/4” - 16
7/8” - 14

1.1/16 - 12

1.5/16 - 12

1.5/8 - 12
22
33

Width across flats

of nut part

(mm)

17
17
22
27
32
38
50
27
41

TIGHTENING TORQUE

kgm Nm

±0.5

2.6
4

±0.5

±2

6.7

8

±2

9.7

±3

±3

17
20

±5

8

±2

±5

20

Sealing surface

25.5

39.2

65.7

78.5

95.15

166.7

196.2

78.5

196.2

±4.9

±4.9
±19.6
±19.6

±29.4

±29.4

±49

±19.6

±49

Thread diameter

of nut part

(mm)

9/16” - 18
11/16” - 16
13/16” - 16

1” - 14

1.3/16 - 12

1.7/16 - 12

1.11/16 - 12
2” - 12

Width across flats

of nut part

(mm)

17
22
24
30
36
41
50
57

TIGHTENING TORQUE

kgm Nm

2.3–2.5

3.4–3.9

5.2–5.8

8.2–9.2

12.2–13.3

15.3–17.3

18.4–20.4

20.4–24.4

23–25
33–38
51–57

80–90
120–130
150–170
180–200
200–240

SK714-5 SK815-5 SK815-5 turbo

00-9

COATING MATERIALS

COATING MATERIALS

The recommended coating materials prescribed in Komatsu Utility Shop Manuals are listed below:

Nomenclature Code Applications

Bostik 99 Used to apply rubber pads, rubber gaskets and cork plugs.

Adhesives

Gasket sealant

Loctite 406

Loctite 222 Used for low resistance locking of screws, check nuts and adjustment nuts.

Loctite 242

Loctite 262 Used for high resistant of threaded parts that can be removed with normal tools.

Loctite 270

Loctite 542 Used for sealing the union threads for hydraulic tubes.

Loctite 573

Loctite 601

Loctite 675

Loctite 542

Loctite 510

Used to apply resin, rubber, metallic and non-metallic parts when a fast, strong
seal is needed.

To prevent the loosening of bolts, nuts and plugs and the leakage of oil. Used for
medium resistance locking of screws and nuts of every type, and for loc king
keys and bearings.

Used for high resistant locking and for sealing threaded parts, bolts and stud
bolts.

Used for sealing rather exact plane surfaces when the option of possible future
dismantling is required.

Used for high resistant locking of mechanical components that can be removed
only after heating

Used to lock cylindrical couplings and for the permanent locking of threaded
parts, and also to lock shafts to bearings, gears, pulleys, pins, bushings, etc.

Used by itself to seal grease fittings, tapered screw fittings and tapered screw
fittings in hydraulic circuits of less than 50 mm in diameter.

Used by itself on mounting flat surface
(Clearance between surfaces within 0.2 mm)

Antifriction compound
(Lubricant including
Molybdenum disulfide)

Grease
(Lithium grease)

Vaseline

00-10

Loctite 518

Litio EP MS2

NLGI 2

Litio EP

NLGI 2

-----

Used by itself on mounting flat surface
(Clearance between surfaces within 0.5 mm

Applied to bearings and taper shaft to facilitate press-fitting and to prevent
sticking, burning or rusting.

Applied to bearings, sliding parts and oil seals for lubrication, rust prevention
and facilitation of assembling work.

Used for protecting battery electrode terminals from corrosion

SK714-5 SK815-5 SK815-5 turbo

ELECTRIC WIRE CODE

ELECTRIC

In the wiring diagrams various colour and symbols are employed to indicate the thickness of wires.
This wire code table will help you understand WIRING DIAGRAMS.
Example: R–N 1.5 indicates a cable having a nominal number 1.5 and red coating with black stripe.

CLASSIFICATION BY THICKNESS

Nominal

number

0.5 16 0.20 0.35 1.55 3.5
1 14 0.30 0.99 2.80 11

1.5 21 0.30 1.48 3.35 14

2.5 35 0.30 2.47 3.80 20
4 56 0.30 3.95 4.60 28
6 84 0.30 5.93 5.20 37

Number

strands

Copper wire
Ø of strands

(mm)

Cross section

(mm)

Cable O.D.

(mm)

Current rating

(A)

CLASSIFICATION BY COLOUR AND CODE

Primary Auxiliary
Code A A–B A/B A–G – A–N A/N A–R A–V A/V
Colour Light Blue Light Blue – White Light Blue–Yellow Light Blue–Black Light Blue–Red Light Blue–Green
Code B B–G – B–N B/N B–R B/R – – – –
Colour White White–Yellow White–Black White–Red – –
Code C C–B C/B C–L – C–N C/N – – – –
Colour Orange Orange–White Orange–Blue Orange–Black – –
Code G G–N G/N – G/R – – – – – –
Colour Yellow Yellow–Black Yellow–Red – – –
Code H H–L – H–N – H–R H/R – – – –
Colour Grey Grey–Blue Grey–Black Grey–Red – –
Code L – L/B L–G L/G L–N L/N L–R L/R – –
Colour Blue Blue–White Blue–Yellow Blue–Black Blue–Red –
Code M M–B M/B M–N – M–V – – – – –
Colour Brown Brown–White Brown–Black Brown–Green – –
CodeN ––––––––––
ColourBlack–––––
Code R R–G – R–N R/N R–V – – – – –
Colour Red Red–Yellow Red–Black Red–Green – –
Code S S–G – S–N S/N – – – – – –
Colour Pink Pink–Yellow Pink–Black – – –
Code V V–B V/B V–N V/N – – – – – –
Colour Green Green–White Green–Black – – –
Code Z Z–B – Z–N Z/N – – – – – –
Colour Violet Violet–White Violet–Black – – –

COMPOSITION OF THE COLOURS

The coloration of two-colour wires is indicated by the composition of the symbol listed.
Example: G–V = Yellow-Green with longitudinal colouring

G/V = Yellow-Green with transversal colouring

SK714-5 SK815-5 SK815-5 turbo

00-11

WEIGHT TABLE

WEIGHT TABLE

This weight table is a guide for use when transporting or handling components.

Unit: kg
Machine model SK714-5 SK815-5 SK815-5 turbo
Engine assembly - Muffler - Exhaust pipe 200 200 200
Radiator 22 22 22
Hydraulic oil tank (without oil) 21.5 21.5 21.5
Engine hood 14.5 14.5 14.5
Cabin (without seat) 215 215 215
Seat:

• standard

• witj suspension
Engine-pump group 278–285 283–290 283–290
Piston pump:

• standard

• High-Flow

10
16

78
84

10
16

82
88

10
16

82

88
Wheel, assy. (standard) 43 44 44
Control valve:

• 3-spool (standard)

• 4-spool (High-Flow)
Work equipment (without bucket)

• Arm

• Work equipment support

• Bucket (L=1460 mm)

• Tilt cylinder

• Dump cylinder

19

21.5

280

49

159

17,3

12

19

21.5

295

49

171,5

16,8

12

19

21.5

295

49

171,5

16,8

12

00-12

SK714-5 SK815-5 SK815-5 turbo

TABLE OF OIL AND COOLANT QUANTITIES

TABLE OF OIL AND COOLANT QUANTITIES

RESERVOIR

Engine oil pan

Hydraulic system
and hydrostatic
trasmissione

Hydraulic circuit
with biodegradable
oil

Final transmission
case (ea.)

Fuel tank DIESEL OIL

KIND OF

FLUID

OIL

• API CD

OIL

• API CD

OIL

• API CD

--

AMBIENT TEMPERATURE CAPACITY (

30 -- 20

✽

--

10 0 10 20 30 40 50°C

SAE 10W

SAE 30

SAE 40

SAE 10W-30

SAE 5W-30

SAE 10W

SAE 5W-30

SAE 10W-30

ASTM D975 N.2

Specified Refill

SK714-5

SK815-5:

SK815-5 turbo:

ᐉ)

88

38 27

38 27

15.5 15.5

38
50

–

Engine cooling
system

WATER +
ANTIFREEZE

PERMANENT
COOLANT

9–

9–

✽ ASTM D975 N.

IMPORTANT:

(1) When the diesel oil sulphur content is less then 0.5%, change the engine oil according to the periodic maintenance

intervals indicated in the operation and maintenance manual. In the diesel oil sulphur content exceeds 0.5% change
the engine oil according to the following table:

Sulphur content Engine oil change interval

from 0.5 to 1.0% 1/2

over 1.0% 1/4

of regular interval
of regular interval

(2) When starting the engine at temperatures below 0 °C, use engine oil SAE 10W, 20W-20 and 10W-30, even if during

the day the temperature increases by 10 °C.

(3) Use engine oil with CD classification; if oil with CD classification is used, reduce the engine oil change interval by a

half.

(4) Use original products, which have characteristics specifically formulated and approved for the engine, the hydraulic

circuit of equipment and for reductions.

First filling quantity:

total quantity of oil, including the oil for the components and pipes.

Oil change quantity:

quantity of oil necessary to fill the system or unit during the normal inspection and maintenance operations.
ASTM: American Society of Testing and Materials
SAE: Society of Automotive Engineers
API: American Petroleum Institute

SK714-5 SK815-5 SK815-5 turbo

00-13

PAGE INTENTIONALLY

LEFT BLANK

CONVERSION TABLE

METHOD OF USING THE CONVERSION TABLE

The conversion table in this section is provided to enable simple conversion of figures.
For details of the method of using the conversion table, see the example given below.

EXAMPLE

• Method of using the conversion table to convert from millimeters to inches.

1. Convert 55 mm into inches.

CONVERSION TABLE

0.236

0.630

1.024

A

, then drow a horizontal line from

1 mm = 0.03937 in.

0.276

0.669

1.063

0.315

0.709

1.102

0.354

0.748

1.142

1 - Locate the number 50 in the vertical column at the left side, take this as

A

.

2 - Locate the number 5 in the row across the top, take this as , then draw a perpendicular line down from .
3 - Take the point where the two lines cross as . This point gives the value when converting from mil-

limeters to inches. Therefore,

2. Convert 550 mm into inches

1 - The number 550 does not appear in the table, so divide by 10 (move the decimal point one place to the left) to

convert it to 55 mm.
2 - Carry out the same procedure as above to convert 55 mm to 2.165 in.
3 - The original value (550 mm) was divided by 10, so multiply 2.165 in. by 10 (move the decimal point one place to

the right) to return to the original value. This gives 550 mm = 21.65 in.

From millimeters to inches

0 1 2 3 4 5 6 7 8 9

0.039

0.433

0.827

10
20

0

0

0.394

0.787

55 mm =2.165 in.

0.079

0.472

0.866

0.118

0.512

0.906

C C

0.157

0.551

0.945

0.197

0.591

0.984

B

B

30
40

50

1.181

1.575

1.969

1.220

1.614

2.008

A

60
70
80
90

2.362

2.756

3.150

3.543

2.402

2.795

3.189

3.583

SK714-5 SK815-5 SK815-5 turbo

1.260

1.654

2.047

2.441

2.835

3.228

3.622

1.299

1.693

2.087

2.480

2.874

3.268

3.661

1.339

1.732

2.126

2.520

2.913

3.307

3.701

1.378

1.772

C

2.165

2.559

2.953

3.346

3.740

1.417

1.811

2.205

2.598

2.992

3.386

3.780

1.457

1.850

2.244

2.638

3.032

3.425

3.819

1.496

1.890

2.283

2.677

3.071

3.465

3.858

1.536

1.929

2.323

2.717

3.110

3.504

3.898

00-15

From mm to in.

CONVERSION TABLE

1 mm = 0.03937 in.

0123456789

0
10
20
30
40

50
60
70
80
90

From kg to lb.

0

0.394

0.787

1.181

1.575

1.969

2.362

2.756

3.150

3.543

0.039

0.433

0.827

1.220

1.614

2.008

2.402

2.795

3.189

3.583

0.079

0.472

0.866

1.260

1.654

2.047

2.441

2.835

3.228

3.622

0.118

0.512

0.906

1.299

1.693

2.087

2.480

2.874

3.268

3.661

0.157

0.551

0.945

1.339

1.732

2.126

2.520

2.913

3.307

3.701

0.197

0.591

0.984

1.378

1.772

2.165

2.559

2.953

3.346

3.740

0.236

0.630

1.024

1.417

1.811

2.205

2.598

2.992

3.386

3.780

0.276

0.669

1.063

1.457

1.850

2.244

2.638

3.032

3.425

3.819

0.315

0.709

1.102

1.496

1.890

2.283

2.677

3.071

3.465

3.858

1 kg = 2.2046 lb.

0.354

0.748

1.142

1.536

1.929

2.323

2.717

3.110

3.504

3.898

0
10
20
30
40

50
60
70
80
90

0123456789

0

22.05

44.09

66.14

88.18

110.23

132.28

154.32

176.37

198.42

2.20

24.25

46.30

68.34

90.39

112.44

134.48

156.53

178.57

200.62

4.41

26.46

48.50

70.55

92.59

114.64

136.69

158.73

180.78

202.83

6.61

28.66

50.71

72.75

94.80

116.85

138.89

160.94

182.98

205.03

8.82

30.86

51.91

74.96

97.00

119.05

141.10

163.14

185.19

207.24

11.02

33.07

55.12

77.16

99.21

121.24

143.30

165.35

187.39

209.44

13.23

35.27

57.32

79.37

101.41

123.46

145.51

167.55

189.60

211.64

15.43

37.48

59.53

81.57

103.62

125.66

147.71

169.76

191.80

213.85

17.64

39.68

61.73

83.78

105.82

127.87

149.91

171.96

194.01

216.05

19.84

41.89

63.93

85.98

108.03

130.07

152.12

174.17

196.21

218.26

00-16

SK714-5 SK815-5 SK815-5 turbo

From liter to U.S. Gall.

0123456789

CONVERSION TABLE

1 ᐉ = 0.2642 U.S. Gall.

0
10
20
30
40

50
60
70
80
90

0

2.642

5.283

7.925

10.567

13.209

15.850

18.492

21.134

23.775

From liter to U.K. Gall.

0.264

2.906

5.548

8.189

10.831

13.473

16.115

18.756

21.398

24.040

0.528

3.170

5.812

8.454

11.095

13.737

16.379

19.020

21.662

24.304

0.793

3.434

6.076

8.718

11.359

14.001

16.643

19.285

21.926

24.568

1.057

3.698

6.340

8.982

11.624

14.265

16.907

19.549

22.190

24.832

1.321

3.963

6.604

9.246

11.888

14.529

17.171

19.813

22.455

25.096

1.585

4.227

6.869

9.510

12.152

14.795

17.435

20.077

22.719

25.361

1.849

4.491

7.133

9.774

12.416

15.058

17.700

20.341

22.983

25.625

2.113

4.755

7.397

10.039

12.680

15.322

17.964

20.605

23.247

25.889

1 ᐉ = 0.21997 U.K. Gall.

2.378

5.019

7.661

10.303

12.944

15.586

18.228

20.870

23.511

26.153

0
10
20
30
40

50
60
70
80
90

0123456789

0

2.200

4.399

6.599

8.799

10.998

13.198

15.398

17.598

19.797

0.220

2.420

4.619

6.819

9.019

11.281

13.418

15.618

17.818

20.017

0.440

2.640

4.839

7.039

9.239

11.438

13.638

15.838

18.037

20.237

0.660

2.860

5.059

7.259

9.459

11.658

13.858

16.058

12.257

20.457

0.880

3.080

5.279

7.479

9.679

11.878

14.078

16.278

18.477

20.677

1.100

3.300

5.499

7.969

9.899

12.098

14.298

16.498

18.697

20.897

1.320

3.520

5.719

7.919

10.119

12.318

14.518

16.718

18.917

21.117

1.540

3.740

5.939

8.139

10.339

12.528

14.738

16.938

19.137

21.337

1.760

3.950

6.159

8.359

10.559

12.758

14.958

17.158

19.357

21.557

1.980

4.179

6.379

8.579

10.778

12.978

15.178

17.378

19.577

21.777

SK714-5 SK815-5 SK815-5 turbo

00-17

From Nm to lb.ft.

0123456789

CONVERSION TABLE

1 Nm = 0.737 lb.ft.

0
10
20
30
40

50
60
70
80
90

100
110
120

0

7.370

14.740

22.110

29.480

36.850

44.220

51.590

58.960

66.330

73.700

81.070

88.440

0.737

8.107

15.477

22.847

30.217

37.587

44.957

52.327

59.697

67.067

74.437

81.807

89.177

1.474

8.844

16.214

23.584

30.954

38.324

45.694

53.064

60.434

67.804

75.174

82.544

89.914

2.211

9.581

16.951

24.321

31.691

39.061

46.431

53.801

61.171

68.541

75.911

83.281

90.651

2.948

10.318

17.688

25.058

32.428

39.798

47.168

54.538

61.908

69.278

76.648

84.018

91.388

3.685

11.055

18.425

25.795

33.165

40.535

47.905

55.275

82.645

70.015

77.385

84.755

92.125

4.422

11.792

19.162

26.532

33.902

41.272

48.642

56.012

63.382

70.752

78.122

85.492

92.862

5.159

12.529

19.899

27.269

34.639

42.009

49.379

56.749

64.119

71.489

78.859

86.229

93.599

5.896

13.266

20.636

28.006

35.376

42.746

50.116

57.486

64.856

72.226

79.596

86.966

94.336

6.633

14.003

21.373

28.743

36.113

43.483

50.853

58.223

65.593

72.963

80.333

87.703

95.073
130
140

150
160
170
180
190

95.810

103.180

110.550

117.920

125.290

132.660

140.030

96.547

103.917

111.287

118.657

126.027

133.397

140.767

97.284

104.654

112.024

119.394

126.764

134.134

141.504

98.021

105.391

112.761

120.131

127.501

134.871

142.241

98.758

106.128

113.498

120.868

128.238

135.608

142.978

99.495

106.865

114.235

121.605

128.975

136.345

143.715

100.232

107.602

114.972

122.342

129.712

137.082

144.452

100.969

108.339

115.709

123.079

130.449

137.819

145.189

101.706

109.076

116.446

123.816

131.186

138.556

145.926

102.443

109.813

117.183

124.553

131.923

139.293

146.663

00-18

SK714-5 SK815-5 SK815-5 turbo

From Nm to kgm

0123456789

CONVERSION TABLE

1 Nm = 0.102 kgm

0
10
20
30
40

50
60
70
80
90

100
110
120

0

1.020

2.040

3.060

4.080

5.100

6.120

7.140

8.160

9.180

10.200

11.220

12.240

0.102

1.222

2.142

3.162

4.182

5.202

6.222

7.242

8.262

9.282

10.302

11.322

12.342

0.204

1.224

2.244

3.264

4.284

5.304

6.324

7.344

8.364

9.384

10.404

11.424

12.444

0.306

1.326

2.346

3.366

4.386

5.406

6.426

7.446

8.466

9.486

10.506

11.526

12.546

0.408

1.428

2.448

3.468

4.488

5.508

6.528

7.548

8.568

9.588

10.608

11.628

12.648

0.510

1.530

2.550

3.570

4.590

5.610

6.630

7.650

8.670

9.690

10.710

11.730

12.750

0.612

1.632

2.652

3.672

4.692

5.712

6.732

7.752

8.772

9.792

10.812

11.832

12.852

0.714

1.734

2.754

3.774

4.794

5.814

6.834

7.854

8.874

9.894

10.914

11.934

12.954

0.816

1.836

2.856

3.876

4.896

5.916

6.936

7.956

8.976

9.996

11.016

12.036

13.056

0.918

1.938

2.958

3.978

4.998

6.018

7.038

8.058

9.078

10.098

11.118

12.138

13.158
130
140

150
160
170
180
190

13.260

14.280

15.300

16.320

17.340

18.360

19.380

13.362

14.382

15.402

16.422

17.442

18.462

19.482

13.464

14.484

15.504

16.524

17.544

18.564

19.584

13.566

14.586

15.606

16.626

17.646

18.666

19.686

13.668

14.688

15.708

16.728

17.748

18.768

19.788

13.770

14.790

15.810

16.830

17.850

18.870

19.890

13.872

14.892

15.912

16.932

17.952

18.972

19.992

13.974

14.994

16.014

17.034

18.054

19.074

20.094

14.076

15.096

16.116

17.136

18.156

19.176

20.196

14.178

15.198

16.218

17.238

18.258

19.278

20.298

SK714-5 SK815-5 SK815-5 turbo

00-19

From kgm to lb.ft.

0123456789

CONVERSION TABLE

1 kgm = 7.233 lb.ft.

0
10
20
30
40

50
60
70
80
90

100
110
120

0

72.3

144.7

217.0

289.3

361.7

434.0

506.3

578.6

651.0

723.3

795.6

868.0

7.2

79.6

151.9

224.2

296.6

368.9

441.2

513.5

585.9

658.2

730.5

802.9

875.2

14.5

86.8

159.1

231.5

303.8

376.1

448.5

520.8

593.1

665.4

737.8

810.1

882.4

21.7

94.0

166.4

238.7

311.0

383.4

455.7

528.0

600.3

672.2

745.0

817.3

889.7

28.9

101.3

173.6

245.9

318.3

390.6

462.9

535.2

607.6

679.9

752.2

824.6

896.9

36.2

108.5

180.8

253.2

325.5

397.8

470.2

542.5

614.8

687.1

759.5

831.8

904.1

43.4

115.7

188.1

260.4

332.7

405.1

477.4

549.7

622.0

694.4

766.7

839.0

911.4

50.6

123.0

195.3

267.6

340.0

412.3

484.6

556.9

629.3

701.6

773.9

846.3

918.6

57.9

130.2

202.5

274.9

347.2

419.5

491.8

564.2

636.5

708.8

781.2

853.5

925.8

65.1

137.4

209.8

282.1

354.4

426.8

499.1

571.4

643.7

716.1

788.4

860.7

933.1
130
140

150
160
170
180
190

940.3

1012.6

1084.9

1157.3

1129.6

1301.9

1374.3

947.5

1019.9

1092.2

1164.5

1236.8

1309.2

1381.5

954.8

1027.1

1099.4

1171.7

1244.1

1316.4

1388.7

962.0

1034.3

1106.6

1179.0

1251.3

1323.6

1396.0

969.2

1041.5

1113.9

1186.2

1258.5

1330.9

1403.2

876.5

1048.8

1121.1

1193.4

1265.8

1338.1

1410.4

983.7

1056.0

1128.3

1200.7

1273.0

1345.3

1417.7

990.9

1063.2

1135.6

1207.9

1280.1

1352.6

1424.9

998.2

1070.5

1142.8

1215.1

1287.5

1359.8

1432.1

1005.4

1077.7

1150.0

1222.4

1294.7

1367.0

1439.4

00-20

SK714-5 SK815-5 SK815-5 turbo

From bar to psi (lb/in2)

0123456789

CONVERSION TABLE

1 bar = 14.503 psi

0
10
20
30
40

50
60
70
80
90

100
110
120

0

145.0

290.0

435.1

580.1

725.1

870.2

1015.2

1160.2

1305.3

1450.3

1595.3

1740.4

14.5

159.5

304.6

449.6

594.6

739.6

884.7

1029.7

1174.7

1319.8

1464.8

1609.8

1754.9

29.0

174.0

319.1

464.1

609.1

754.1

899.2

1044.2

1189.2

1334.3

1479.3

1624.3

1769.4

43.5

188.5

333.6

478.6

623.6

768.6

913.7

1058.7

1203.7

1348.8

1493.8

1638.8

1783.9

58.0

203.0

348.1

493.1

638.1

783.2

928.2

1073.2

1218.2

1363.3

1508.3

1653.3

1798.4

72.5

217.5

362.6

507.6

652.6

797.7

942.7

1087.7

1232.7

1377.8

1522.8

1667.8

1812.9

87.0

232.0

377.1

522.1

667.1

812.2

957.2

1102.2

1247.2

1392.3

1537.3

1682.3

1827.4

101.5

246.5

391.6

536.6

681.6

826.7

971.7

1116.7

1261.8

1406.8

1551.8

1696.8

1841.9

116.0

261.0

406.1

551.1

696.1

841.2

986.2

1131.2

1276.3

1421.3

1566.3

1711.3

1856.4

130.5

275.6

420.6

565.6

710.6

855.7

1000.7

1145.7

1290.8

1435.8

1580.8

1725.8

1870.8
130
140

150
160
170
180
190

200
210
220
230
240

1885.4

2030.4

2175.4

2320.5

2465.5

2610.5

2755.6

2900.6

3045.6

3190.7

3335.7

3480.7

1899.9

2044.9

2189.9

2335.0

2480.0

2625.0

2770.0

2915.1

3060.1

3205.2

3350.2

3495.2

1914.4

2059.4

2204.4

2349.5

2494.5

2639.5

2784.6

2929.6

3074.6

3219.7

3364.7

3509.7

1928.9

2073.9

2218.9

2364.0

2509.0

2654.0

2799.1

2944.1

3089.1

3234.2

3379.2

3524.2

1943.4

2088.4

2233.5

2378.5

2523.5

2668.5

2813.6

2958.6

3103.6

3248.7

3393.7

3538.7

1957.9

2102.9

2248.0

2393.0

2538.0

2683.0

2828.1

2973.1

3118.1

3263.2

3408.2

3553.2

1972.4

1217.4

2262.5

2407.5

2552.5

2697.7

2842.6

2987.6

3132.6

3277.7

3422.7

3567.7

1986.9

2131.9

2277.0

2422.0

2567.0

2712.1

2857.1

3002.1

3147.1

3192.2

3437.2

3582.2

2001.4

2146.4

2291.5

2436.5

2581.5

2726.6

2871.6

3016.6

3161.6

3306.7

3451.7

3596.7

2015.9

2160.9

2306.0

2451.0

2596.0

2641.1

2886.1

3031.1

3176.1

3321.2

3466.2

3611.2

SK714-5 SK815-5 SK815-5 turbo

00-21

CONVERSION TABLE

TEMPERATURE

Fahrenheit-Centigrade conversion; a simple way to convert a Fahrenhe it temperature reading int o a Centigrade tem­perature reading or vice versa is to enter the accompanying table in the center or boldface column of figures.
These figures refer to the temperature in either Fahrenheit or Centigrade degrees.
If it is desired to convert from Fahrenheit to Centigrade degrees, consider the center column as a table of Fahrenheit tem­peratures and read the corresponding Centigrade temperature in the column at the left.
If it is desired to convert from Centigrade to Fahrenheit degrees, consider the center column as a table of Centigrade val­ues and read the corresponding Fahrenheit temperature on the right.

1 °C = 33.8°F

°C

–40.4
–37.2
–34.4
–31.7
–28.9

–28.3
–27.8
–27.2
–26.7
–26.1

–25.6
–25.0
–24.4
–23.9
–23.3

–22.8
–22.2
–21.7
–21.1
–20.6

–40
–35
–30
–25
–20

–19
–18
–17
–16
–15

–14
–13
–12
–11
–10

–9
–8
–7
–6
–5

°F °C °F °C °F °C °F

–40.0
–31.0
–22.0
–13.0

–4.0

–2.2
–0.4

1.4

3.2

5.0

6.8

8.6

10.4

12.2

14.0

15.8

17.6

19.4

21.2

23.0

–11.7
–11.1
–10.6
–10.0

–9.4

–8.9
–8.3
–7.8
–7.2
–6.7

–6.1
–5.6
–5.0
–4.4
–3.9

–3.3
–2.8
–2.2
–1.7
–1.1

11
12
13
14
15

16
17
18
19
20

21
22
23
24
25

26
27
28
29
30

51.8

53.6

55.4

57.2

59.0

60.8

62.6

64.4

66.2

68.0

69.8

71.6

73.4

75.2

77.0

78.8

80.6

72.4

84.2

86.0

7.8

8.3

8.9

9.4

10.0

10.6

11.1

11.7

12.2

12.8

13.3

13.9

14.4

15.0

15.6

16.1

16.7

17.2

17.8

18.3

46
47
48
49
50

51
52
53
54
55

56
57
58
59
60

61
62
63
64
65

144.8

116.6

118.4

120.2

122.0

123.8

125.6

127.4

129.2

131.0

132.8

134.6

136.4

138.2

140.0

141.8

143.6

145.4

147.2

149.0

27.2

27.8

28.3

28.9

29.4

30.0

30.6

31.1

31.7

32.2

32.8

33.3

33.9

34.4

35.0

35.6

36.1

36.7

37.2

37.8

81
82
83
84
85

86
87
88
89
90

91
92
93
94
95

96
97
98
99

100

117.8

179.6

181.4

183.2

185.0

186.8

188.6

190.4

192.2

194.0

195.8

197.6

199.4

201.2

203.0

204.8

206.6

208.4

210.2

212.0

–20.0
–19.4
–18.9
–18.3
–17.8

–17.2
–16.7
–16.1
–15.6
–15.0

–14.4
–13.9
–13.3
–12.8
–12.2

00-22

–4
–3
–2
–1

10

24.8

26.6

28.4

30.2

0

32.0

1

33.8

2

35.6

3

37.4

4

39.2

5

41.0

6

42.8

7

44.6

8

46.4

9

48.2

50.0

–0.6

0.0

0.6

1.1

1.7

2.2

2.8

3.3

3.9

4.4

5.0

5.6

6.1

6.7

7.2

31
32
33
34
35

36
37
38
39
40

41
42
43
44
45

87.8

89.6

91.4

93.2

95.0

96.8

98.6

100.4

102.2

104.0

105.8

107.6

109.4

111.2

113.0

18.9

19.4

20.0

20.6

21.1

21.7

22.2

22.8

23.3

23.9

24.4

25.0

25.6

26.1

26.7

66
67
68
69
70

71
72
73
74
75

76
77
78
79
80

150.8

152.6

154.4

156.2

158.0

159.8

161.6

163.4

165.2

167.0

168.8

170.6

172.4

174.2

176.0

40.6

43.3

46.1

48.9

51.7

54.4

57.2

60.0

62.7

65.6

68.3

71.1

73.9

76.7

79.4

105
110
115
120
125

130
135
140
145
150

155
160
165
170
175

221.0

230.0

239.0

248.0

257.0

266.0

275.0

284.0
2930

302.0

311.0

320.0

329.0

338.0

347.0

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

P.T.O......................................................................... 2

Power train ................................................................3

Transmission ............................................................. 4

Final drive.................................................................. 6

Hydraulic circuit

SK714-5 (Standard)................................................. 13

Hydraulic circuit

SK714-5 (Road homologation)................................ 14

Hydraulic circuit

SK815-5 - SK815-5 turbo (Standard)...................... 15

Hydraulic circuit

SK815-5 - SK815-5 turbo (Road homologation)...... 16

Hydraulic pump........................................................ 17

Control valve (3-Spool)............................................ 36

Control valve (4-Spool)............................................ 39

CLSS....................................................................... 43

Solenoid valve......................................................... 51

Accumulator............................................................. 53

Pattern change valve (Optional)...............................54

R.H. PPC Valve (Standard)......................................58

R.H. PPC Valve (Pattern Change) (Optional) ..........62

L.H. PPC Valve (Standard) ......................................66

L.H. PPC VALVE (Pattern Change) (Optional) ........70

Cylinders ..................................................................74

Electrical diagram (Engine line)................................75

Electrical diagram (Frame line standard) .................79

Electrical diagram (Frame line optional) ..................83

Electrical diagram (Cabin line standard) ..................87

Electrical diagram (Cabin line optional)....................93

Electrical diagram (Top-cabin light line standard)..101
Electrical diagram (Top-cabin light line omologation).103

Electrical diagram (Top-cabin light line optional)....105

SK714-5 SK815-5 SK815-5 turbo

10-1

STRUCTURE AND FUNCTION

P.T.O.

P. T. O .

4

1

2

3

5

RKS01090

1. Joint

2. Spring pin

3. Dumper

4. Flywheel cover

5. Hydraulic pump

10-2

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

POWER TRAIN

POWER TRAIN

1. Engine

2. Hydraulic pump

3. Control valve

4. Solenoid valve
4a. Servocontrol
4b. Speed increment
4c. Parking brake

8

4

3

ABC

5

7

6

8

5. High-flow solenoid valve

6. L.H. final drive

7. R.H. final drive

8. Axle

8

1

2

8

RKS00990

SK714-5 SK815-5 SK815-5 turbo

10-3

STRUCTURE AND FUNCTION

TRANSMISSION

B B

A

A

C C

TRANSMISSION

3

Section A - A

1. L.H. final drive

2. Front trasmission chain

3. Rear trasmission chain

4. Master link

X

1

4

2

2

View X

3

RKS01001

10-4

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

1

TRANSMISSION

4532

Section B - B

4372

6

Section C -C

RKS01010

1. Front wheel

2. Axle housing

3. Sprocket

4. Shaft

5. Front trasmission chain

6. Rear wheel

7. Rear trasmission chain

SK714-5 SK815-5 SK815-5 turbo

10-5

STRUCTURE AND FUNCTION

FINAL DRIVE

FINAL DRIVE

Z

A

View Z

L.H. FINAL DRIVE

a. A Port – To hydraulic pump (PA2 port)
b. B Port – To hydraulic pump (PB2 port)
c. PP1 Port – From solenoid valve group ST1(A Port)

(2nd speed)

d. PP2 Port – From solenoid valve group ST1 (C Port)

(parking brake)

e. DR Port – To hydraulic tank

d

ce

b

A

a

RKS01020

R.H. FINAL DRIVE

a. A Port – To hydraulic pump (PB1 port)
b. B Port – To hydraulic pump (PA1 port)
c. PP1 Port – From solenoid valve group ST1(A Port)

(2nd speed)

d. PP2 Port – From solenoid valve group ST1 (C Port)

(parking brake)

e. DR Port – To hydraulic tank

10-6

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

FINAL DRIVE

B

B

45 6

7

1

23

22

8

9

10

11

12

13

14

15

16

17

18192021

Section A - A

1. Shaft

2. Bearing

3. Bearing

4. Body

5. Pin

6. Gear

7. Shoe

8. Brake piston

9. Plate

10. Cylinder block

11. Bearing

12. Spring

13. Piston

14. Brake spring

15. Bushing

16. Retainer plate

26

27

25

24

26

23

17. Swash plate

18. Plate

19. Shaft

20. Flange

21. Collar

22. Gasket

23. Plug

24. Spring

Section B - B

2928

RKS01031

25. Spool

26. Plug

27. Spool

28. Plug

29. Spring

SK714-5 SK815-5 SK815-5 turbo

10-7

STRUCTURE AND FUNCTION

DESCRIPTION

The final drive motor consists of:

1. 2-speed hydraulic motor

2. Selector valve

3. Reduction gearing

1. HYDRAULIC MOTOR

Function

The hydraulic motor is of the axial piston type, and converts hydraulic energy supplied by the pump into rotary motion.

Operation

The hydraulic oil arriving from the selector valve is sent on to the valve plate (1). When the oil is sent to port “A” of the
valve, it flows into the corresponding port on the cylinder block (2) and presses against the pistons (3).
This pressure is converted into rotary motion by a swash plate (4) and hence transmitted to the shaft (5). The shaft and
the cylinder block have been integrated into one piece by means of splined toothing.
The return oil is sent to the pump through port “B”.
Rotation in the opposite direction is achieved by sending the oil to port “B” instead of to port “A”..

FINAL DRIVE

5

4

2

1

3

B

A

RKS01050

Varying the displacement

The swash plate (4), which has two surfaces “A” and “B” on the side opposite the sliding side for the shoes (6), is sup­ported by two bearings (7) attached to the body of the motor (8).
The position of the bearings is eccentric with respect to the axis of the shaft and when running at low speed the surface
“A” remains in contact with the body of the motor through the pressure exerted by the pistons (3) and by the force of a
spring (9) mounted in the cylinder block (2).
The angle of the swash plate is
When an increase in speed is demanded, the oil is sent under pressure to the command piston (10). The command pi­ston (10) moves to the left ( ) until the surface “B” makes contact with the housing and the angle of the swash plate
becomes

β (the displacement of the motor is reduced).

α.

10-8

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

.

FINAL DRIVE

8

10

B

8

10

B

6

4

7

A

␣

23

9

Brake

The hydraulic motor is equipped with a negative brake.

• When the motor is at a standstill, or when the operator applies the brake, the braking piston (1) is pushed to the left
( ) by the force of the springs (2).
The friction disk (3), which has b een integrated with the cylinder block by means of semicircular groo ves, is com­pressed between steel disks (4) and (5), which are integrated with the housing, and is thus blocked. The drive shaft
(6) can therefore no longer turn.

• When the motor is running and the operator disengages the brake, oil is sent under pressure to the chamber “A”.
The force exerted by the oil is greater than the force of the springs (2) and the piston (1) is therefore pushed to the
right ( ) thus releasing the friction disk (3) and permitting rotation of the cylinder block (7) (and also of the drive
shaft).

4

3

3

7

A

␤

923

RKS01040

5

3

4

7

6

SK714-5 SK815-5 SK815-5 turbo

A

1

2

5

3

1

2

4

7

A

6

RKS01060

10-9

STRUCTURE AND FUNCTION

FLUSHING RELIEF VALVE

2.

When the oil is sent under pressure to the “A” port, the oil that activated the motor returns to the pump through the “B”
port.
The pressurised oil sent to the “A” port is also introduced into the chamber “C”. It now pushes the selector valve (1) to
the right ( ). This opens communication between the “B” port and the oil gallery “D”, which is connected to the over­pressure limitation valve (2).
If the pressure present at port “B” exceeds the calibration value of the overpressure limitation valve (2), this valve will
open and discharge the excess oil into the reduction gears.
The valve also functions in the same way when the pressurised oil is sent to the “B” port. The only difference is that the
selector valve moves to the left ( ), and the oil gallery “D” communicates with the “A” port.
.

FINAL DRIVE

C

2

D

1

AB

C

2

D

1

AB

RKS01070

10-10

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

REDUCTION GEARING

3.

Function

This final drive motor is equipped with a one-stage epicycloidal reduction gear that converts the high rotation speed and
low torque of the hydraulic motor into low speed and high torque at the swing pinion.

Operating principle

The rotary movement of the output shaft of the motor is transmitted to the gear (s1) and hence to the bevel gears (b1) whi­ch are integrated with the planetary gear (1).
Since the gear (a1) is fixed with respect to the output shaft of the hydraulic motor, the planeta ry gear is obliged to turn, mo­ving with it the output shaft (2) of the reduction gearing (connected to the planetary gear by means of grooved toothing).
The reduction ratio of the rotation speed is described by the formula:

R= Zs1/(Zs1+Za1)

Zs1= number of sun gear teeth
Za1= number of ring gear teeth

FINAL DRIVE

b1

1

2

a1

s1

RKS01080

SK714-5 SK815-5 SK815-5 turbo

10-11

PAGE INTENTIONALLY

LEFT BLANK

STRUCTURE AND FUNCTION

HYDRAULIC CIRCUIT SK714-5 (STANDARD)

13

ø

12.7L=3450

(

/

-16Orfs)

12.7L=3450

16

13

(

/

-16Orfs)

16

P

Lift arm
raise

Lift arm cylinder L.H.

Lift arm cylinder R.H.

Bucket cylinder L.H.

ø

9.5L=530

ø

9.5L=530

13

(

ø

9.5L=1100

ø

9.5L=1750

ø

9.5L=1100

ø

9.5L=1750

/

-16Orfs)

16

ø

16 t=2

ø

16 t=2

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

ø

P

Bucket dump

HYDRAULIC CIRCUIT SK714-5 (STANDARD)

P2 P4 P3

P1

T

P

6.5L=400(1/2-20 Jic)

ø

A3

B3

PA3

6.5L=400(1/2-20 Jic)

ø

-18 Jic)

16

/

9

6.5L=600(

ø

-18 Jic)

16

/

9

6.5L=680(

ø

Pout 1 Pout 3 Pout 2 Pout 4

-20 Jic)

-20 Jic)

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

2

/

1

6.4L=435(

ø

A2

P

B2

ø6.

4L=1500(1/2-20 Jic)

PA2

A1

Unload

valve

B1

PA1

Lift arm lower

Relief valve

19.1MPa
(195kg/cm

2

)

ø

6.4L=1500(1/2-20 Jic)

ø6.

4L=950(1/2-20 Jic)

ø6.

4L=950(1/2-20 Jic)

-20 Jic)

2

/

1

6.4L=435(

ø

100 Mesh

-18 Jic)

16

/

9

10L=520(

ø

-18 Jic)

16

/

9

10L=520(

ø

-18 Jic)

16

10L=1050

/

9

ø

(

P1

-20 Jic)

2

/

1

6.4L=435(

ø

P2P4P3

-20 Jic)

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

-18 Jic)

16

10L=1050

/

9

ø

(

-20 Jic)

2

/

1

6.4L=435(

ø

100 Mesh

-18 Jic)

16

/

9

10L=520(

ø

-18 Jic)

16

/

9

10L=520(

ø

Bucket cylinder R.H.

Travel motor L.H.

DR

PP2

PP1

A

6.5L=600

ø

(9/16-18 JIC)

6.5L=500

ø

9

/16-18 JIC)

(

BA

RED

ø

9.5L=530

13

(

/

-16Orfs)

16

ø

9.5L=530

13

(

/

-16Orfs)

16

13

ø

12.7L=1800(

/

-16Orfs)

16

13

ø

12.7L=1800(

/

-16Orfs)

16

13

ø

12.7L=3450(

/

-16Orfs)

ø

16 t=2

ø

16 t=2

PP1

B

ø
ø

ø

ø

16

13

ø

12.7L=3450(

/

-16Orfs)

16

15.9L=950(1”3/16-12 Orfs)

15.9L=950(1”3/16-12 Orfs)

15.9L=950(1”3/16-12 Orfs)

15.9L=950(1”3/16-12 Orfs)

PP2

P

ø

19.1L=1100(1”3/16-12 Orfs)

ø

20L=1000

ø

9.5L=1050(9/16-18 JIC)

T

T

-20 Jic)

-20 Jic)

-20 Jic)

-20 Jic)

2

2

2

2

/

/

/

/

1

1

1

1

6.4L=950(

6.4L=850(

6.4L=650(

6.4L=650(

ø

ø

ø

ø

P4

S3 S4

Engine

4D88E-E1FD

34.7km/2800rpm

PA1 DA1 DB1 DB2 DA2 PA2

E

±40cm3/rev

PB1

E2

±40cm3/rev

T5

PB2

ABC

SV3SV2SV1

P

T

RED

DR

Travel motor R.H.

SK714-5 SK815-5 SK815-5 turbo

ø

9.5L=1300(9/16-18 Jic)

ø

9.5L=1300(9/16-18 Jic)

-12 JIC)

16

/

19.1L=800

1

ø

(1”

-12 JIC)

16

/

19.1L=850

1

ø

(1”

ø

(1”

19L=1650

1

/16-12 JIC)

-12 JIC)

16

/

25.4L=620

5

ø

(1”

ø

ø

16

t.2

19L=1450(1”5/16-12 JIC)

ø

20

-12 JIC)

16

/

25.4L=500

5

ø

(1”

ø

9.5L=1000(9/16-18 Jic)

ø

6.5L=350(9/16-18 Jic)

ø

6.5L=680(9/16-18 Jic)

10-13

STRUCTURE AND FUNCTION

HYDRAULIC CIRCUIT SK714-5 (ROAD HOMOLOGATION)

13

ø

12.7L=3450

(

/

-16Orfs)

12.7L=3450

16

13

(

/

-16Orfs)

16

P

P

Bucket dump

P

Lift arm
raise

Unload

valve

Lift arm cylinder L.H.

Lift arm cylinder R.H.

Bucket cylinder L.H.

ø

9.5L=530

ø

9.5L=530

13

(

ø

9.5L=1100

ø

9.5L=1750

ø

9.5L=1100

ø

9.5L=1750

/

-16Orfs)

16

ø

16 t=2

ø

16 t=2

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

ø

6.5L=400(1/2-20 Jic)

ø

A3

B3

PA3

A2

B2

PA2

A1

B1

PA1

Lift arm lower

Relief valve

19.1MPa
(195kg/cm

6.5L=400(1/2-20 Jic)

ø

2

)

ø6.

4L=1500(1/2-20 Jic)

ø

6.4L=1500(1/2-20 Jic)

ø6.

4L=950(1/2-20 Jic)

ø6.

4L=950(1/2-20 Jic)

T

P

-18 Jic)

16

/

9

6.5L=600(

ø

-18 Jic)

16

/

9

6.5L=680(

ø

P2 P4 P3

P1

Pout 1 Pout 3 Pout 2 Pout 4

-20 Jic)

-20 Jic)

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

100 Mesh

-18 Jic)

16

/

9

10L=520(

ø

HYDRAULIC CIRCUIT SK714-5 (ROAD HOMOLOGATION)

100 Mesh

-18 Jic)

16

/

9

10L=520(

ø

-18 Jic)

16

10L=1050

/

9

ø

(

P1

-20 Jic)

2

/

1

6.4L=435(

ø

P2P4P3

-20 Jic)

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

-18 Jic)

16

/

9

10L=520(

ø

-18 Jic)

16

/

9.5L=1050

9

(

ø

-18 Jic)

16

/

9

10L=520(

ø

Bucket cylinder R.H.

Travel motor L.H.

DR

A

PP2

6.5L=600

ø

(9/16-18 JIC)

ø

6.5L=500

9

/16-18 JIC)

(

BA

PP1

RED

ø

9.5L=530

13

(

/

-16Orfs)

16

ø

9.5L=530

13

(

/

-16Orfs)

16

13

ø

12.7L=1800(

/

-16Orfs)

16

13

ø

12.7L=1800(

/

-16Orfs)

16

13

ø

12.7L=3450(

/

-16Orfs)

ø

16 t=2

ø

16 t=2

PP1

B

ø
ø

ø

ø

16

13

ø

12.7L=3450(

/

-16Orfs)

16

15.9L=950(1”3/16-12 Orfs)

15.9L=950(1”3/16-12 Orfs)

15.9L=950(1”3/16-12 Orfs)

15.9L=950(1”3/16-12 Orfs)

PP2

P

ø

19.1L=1100(1”3/16-12 Orfs)

ø

20L=1000

ø

9.5L=1050(9/16-18 JIC)

T

T

-20 Jic)

-20 Jic)

-20 Jic)

-20 Jic)

2

2

2

2

/

/

/

/

1

1

1

1

6.4L=950(

6.4L=850(

6.4L=650(

6.4L=650(

ø

ø

ø

ø

P4

S3 S4

Engine

4D88E-E1FD

34.7km/2800rpm

PA1 DA1 DB1 DB2 DA2 PA2

E

±40cm3/rev

PB1

E2

±40cm3/rev

T5

PB2

P

T

-18 Jic)

16

10L=470

/

ø

9

(

ø

(9/16-18 Jic)

A

9.5L=1000

BC

SV3SV2SV1

S

RED

Travel motor R.H.

-12 JIC)

16

/

25.4L=620

5

-12 JIC)

16

/

5

(1”

ø

(1”

-12 JIC)

16

/

19.1L=800

1

ø

(1”

ø

19L=1650

1

/16-12 JIC)

(1”

-12 JIC)

16

/

19.1L=850

DR

ø

9.5L=1300(9/16-18 Jic)

ø

9.5L=1300(9/16-18 Jic)

1

ø

(1”

ø

16

t.2

ø

19L=1450(1”5/16-12 JIC)

ø

20

25.4L=500

ø

10-14

ø

10L=470(9/16-18 Jic)

ø

10L=350(9/16-18 Jic)

ø

10L=680(9/16-18 Jic)

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

HYDRAULIC CIRCUIT SK815-5 - SK815-5 turbo (STANDARD)

13

ø

12.7L=3700

(

/

-16Orfs)

12.7L=3700

16

13

(

/

-16Orfs)

16

6.5L=400(1/2-20 Jic)

ø

P

P

Bucket dump

P

Lift arm
raise

Unload

valve

Lift arm cylinder L.H.

Lift arm cylinder R.H.

Bucket cylinder L.H.

ø

9.5L=530

ø

9.5L=530

(

ø

ø

13

/

9.5L=1100

ø

9.5L=1750

9.5L=1100

ø

9.5L=1750

(

-16Orfs)

16

ø

16 t=2

ø

16 t=2

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

/

-16Orfs)

16

ø

A3

B3

PA3

A2

B2

PA2

A1

B1

PA1

Lift arm lower

Relief valve

19.1MPa
(195kg/cm

6.5L=400(1/2-20 Jic)

ø

2

)

ø6.

4L=1500(1/2-20 Jic)

ø

6.4L=1500(1/2-20 Jic)

ø6.

4L=950(1/2-20 Jic)

ø6.

4L=950(1/2-20 Jic)

T

P

-18 Jic)

16

/

9

6.5L=600(

ø

-18 Jic)

16

/

9

6.5L=680(

ø

P2 P4 P3

P1

Pout 1 Pout 3 Pout 2 Pout 4

-20 Jic)

-20 Jic)

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

100 Mesh

-18 Jic)

16

/

9

10L=520(

ø

-18 Jic)

16

/

9

10L=520(

ø

HYDRAULIC CIRCUIT SK815-5 - SK815-5 turbo (STANDARD)

100 Mesh

P1

-18 Jic)

16

10L=1050

/

9

ø

(

-20 Jic)

2

/

1

6.4L=435(

ø

P2P4P3

-20 Jic)

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

-18 Jic)

16

10L=1050

/

9

ø

(

-20 Jic)

2

/

1

6.4L=435(

ø

-18 Jic)

16

/

9

10L=520(

ø

-18 Jic)

16

/

9

10L=520(

ø

Bucket cylinder R.H.

Travel motor L.H.

DR

A

PP2

6.5L=600

ø

(9/16-18 JIC)

ø

6.5L=500

(9/16-18 JIC)

BA

PP1

RED

ø

9.5L=530

13

(

/

-16Orfs)

16

ø

9.5L=530

13

(

/

-16Orfs)

16

13

ø

12.7L=1950(

/

-16Orfs)

16

13

ø

12.7L=1950(

/

-16Orfs)

16

13

ø

12.7L=3700(

/

-16Orfs)

ø

16 t=2

ø

16 t=2

PP1

B

ø

ø

ø

ø

16

13

ø

12.7L=3700(

/

-16Orfs)

16

15.9L=1000(1”3/16-12 Orfs)

15.9L=1000(1”3/16-12 Orfs)

15.9L=1000(1”3/16-12 Orfs)

15.9L=1000(1”3/16-12 Orfs)

PP2

P

ø

19.1L=1100(1”3/16-12 Orfs)

ø

20L=1000

ø

9.5L=1050(9/16-18 JIC)

T

T

-20 Jic)

-20 Jic)

-20 Jic)

-20 Jic)

2

2

2

2

/

/

/

/

1

1

1

1

6.4L=950(

6.4L=850(

6.4L=650(

6.4L=650(

ø

ø

ø

ø

P4

7.3

S3 S4

Engine

4D88E-E1FD

34.7km/2800rpm

E

PA1 DA1 DB1 DB2 DA2 PA2

±40cm3/rev

PB1

±40cm3/rev

ø

T5

PB2

ABC

SV3SV2SV1

P

T

RED

DR

Travel motor R.H.

SK714-5 SK815-5 SK815-5 turbo

ø

9.5L=1300(9/16-18 Jic)

ø

9.5L=1300(9/16-18 Jic)

-12 JIC)

16

/

19.1L=800

1

ø

(1”

-12 JIC)

16

/

19.1L=850

1

ø

(1”

ø

(1”

19L=1650

1

/16-12 JIC)

-12 JIC)

16

/

25.4L=620

5

ø

(1”

ø

ø

16

t.2

19L=1450(1”5/16-12 JIC)

ø

20

-12 JIC)

16

/

25.4L=500

5

ø

(1”

ø

9.5L=1000(9/16-18 Jic)

ø

6.5L=350(9/16-18 Jic)

ø

6.5L=680(9/16-18 Jic)

10-15

STRUCTURE AND FUNCTION

HYDRAULIC CIRCUIT SK815-5 - SK815-5 turbo (ROAD HOMOLOGATION)

13

ø

12.7L=3700

(

/

-16Orfs)

12.7L=3700

16

13

(

/

-16Orfs)

16

6.5L=400(1/2-20 Jic)

ø

A3

P

B3

PA3

ø

A2

B2

PA2

A1

B1

PA1

Lift arm lower

Relief valve

19.1MPa
(195kg/cm

2

)

Lift arm
raise

P

Bucket dump

P

Unload

valve

Lift arm cylinder L.H.

Lift arm cylinder R.H.

Bucket cylinder L.H.

ø

9.5L=530

ø

9.5L=530

(

ø

ø

13

/

9.5L=1100

ø

9.5L=1750

9.5L=1100

ø

9.5L=1750

(

-16Orfs)

16

ø

16 t=2

ø

16 t=2

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

(

/

-16Orfs)

16

13

/

-16Orfs)

16

ø

6.5L=400(1/2-20 Jic)

ø6.

4L=1500(1/2-20 Jic)

ø

6.4L=1500(1/2-20 Jic)

ø6.

4L=950(1/2-20 Jic)

ø6.

4L=950(1/2-20 Jic)

T

P

-18 Jic)

16

/

9

6.5L=600(

ø

-18 Jic)

16

/

9

6.5L=680(

ø

P2 P4 P3

P1

Pout 1 Pout 3 Pout 2 Pout 4

-20 Jic)

-20 Jic)

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

2

/

1

6.4L=435(

ø

HYDRAULIC CIRCUIT SK815-5 - SK815-5 turbo (ROAD HOMOLOGATION)

100 Mesh

100 Mesh

-20 Jic)

2

/

1

6.4L=435(

ø

-18 Jic)

16

/

9

10L=520(

ø

-18 Jic)

16

/

9

10L=520(

ø

P1

-18 Jic)

16

10L=1050

/

9

ø

(

-20 Jic)

2

/

1

6.4L=435(

ø

P2P4P3

-20 Jic)

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

-20 Jic)

2

/

1

6.4L=435(

ø

-18 Jic)

16

/

9

10L=520(

ø

-18 Jic)

16

/

9.5L=1050

9

(

ø

-18 Jic)

16

/

9

10L=520(

ø

Bucket cylinder R.H.

Travel motor L.H.

DR

A

PP2

6.5L=600

ø

(9/16-18 JIC)

ø

6.5L=500

9

/16-18 JIC)

(

BA

PP1

RED

ø

9.5L=530

13

(

/

-16Orfs)

16

ø

9.5L=530

13

(

/

-16Orfs)

16

13

ø

12.7L=1950(

/

-16Orfs)

16

13

ø

12.7L=1950(

/

-16Orfs)

16

13

ø

12.7L=3700(

/

-16Orfs)

ø

16 t=2

ø

16 t=2

PP1

B

ø

ø

ø

ø

16

13

ø

12.7L=3700(

/

-16Orfs)

16

15.9L=1000(1”3/16-12 Orfs)

15.9L=1000(1”3/16-12 Orfs)

15.9L=1000(1”3/16-12 Orfs)

15.9L=1000(1”3/16-12 Orfs)

PP2

P

ø

19.1L=1100(1”3/16-12 Orfs)

ø

20L=1000

ø

9.5L=1050(9/16-18 JIC)

T

T

-20 Jic)

-20 Jic)

-20 Jic)

-20 Jic)

2

2

2

2

/

/

/

/

1

1

1

1

6.4L=950(

6.4L=850(

6.4L=650(

6.4L=650(

ø

ø

ø

ø

P4

7.3

S3 S4

Engine

4D88E-E1FD

34.7km/2800rpm

E

PA1 DA1 DB1 DB2 DA2 PA2

±40cm3/rev

PB1

±40cm3/rev

T5

ø

PB2

P

T

-18 Jic)

16

10L=470

/

ø

9

(

ø

(9/16-18 Jic)

A

9.5L=1000

BC

SV3SV2SV1

S

RED

Travel motor R.H.

-12 JIC)

16

/

25.4L=620

5

-12 JIC)

16

/

5

(1”

ø

(1”

-12 JIC)

16

/

19.1L=800

1

ø

(1”

ø

19L=1650

1

/16-12 JIC)

(1”

-12 JIC)

16

/

19.1L=850

DR

ø

9.5L=1300(9/16-18 Jic)

ø

9.5L=1300(9/16-18 Jic)

1

ø

(1”

ø

16

t.2

ø

19L=1450(1”5/16-12 JIC)

ø

20

25.4L=500

ø

10-16

ø

10L=470(9/16-18 Jic)

ø

10L=350(9/16-18 Jic)

ø

10L=680(9/16-18 Jic)

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

HYDRAULIC PUMP

HST PUMP LPV40 + 40 (SK714-5 STANDARD FLOW)

HYDRAULIC PUMP

1 87 2

8

75

6

4

1. Piston pump

2. Control piston

3. Suction safety valve

4. Charge safety valve

5. Charge pump

6. Work equipment pump

7. Adjustment screw (Neutral position)

8. Adjustment screw (Max. displacement

9. Adjustment screw (Pump power control)

3

8 9 9 8

STRUCTURE

This pump is composed of variable swash plate type tan­dem piston pumps (1), control pistons (2), suction safety
valves (3), charge safety valve (4), charge pump (5), work
equipment gear pump (6), and adjustment screws (7), (8),
(9).

RKS00290

SK714-5 SK815-5 SK815-5 turbo

10-17

STRUCTURE AND FUNCTION

HST PUMP LPV40 + 40 (SK714-5 HIGH FLOW)

HYDRAULIC PUMP

1 87 2

8

75

6

4

1. Piston pump

2. Control piston

3. Suction safety valve

4. Charge safety valve

5. Charge pump

6. Work equipment pump

7. Adjustment screw (Neutral position)

8. Adjustment screw (Max. displacement

9. Adjustment screw (Pump power control)

3

8 9 9 8

STRUCTURE

This pump is composed of variable swash plate type tan­dem piston pumps (1), control pistons (2), suction safety
valves (3), charge safety valve (4), charge pump (5), work
equipment gear pump (6), and adjustment screws (7), (8),
(9).

RKS00300

10-18

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

HST PUMP LPV40 + 40 (SK815-5 – SK815-5 turbo STANDARD FLOW)

HYDRAULIC PUMP

10

1 87 2

8

7

5

6

4

1. Piston pump

2. Control piston

3. Suction safety valve

4. Charge safety valve

5. Charge pump

6. Work equipment pump

7. Adjustment screw (Neutral position)

8. Adjustment screw (Max. displacement

11

3

11

8 9 9 8

9. Adjustment screw (Pump power control)

10. AS valve

11. Shuttle valve

STRUCTURE

This pump is composed of variable swash plate type tan­dem piston pumps (1), control pistons (2), suction safety
valves (3), charge safety valves (4), charge pump (5),
work equipment gear pump (6), and adjustment screws
(7), (8), (9), AS valve (10), and shuttle valves (11).

RKS00310

SK714-5 SK815-5 SK815-5 turbo

10-19

STRUCTURE AND FUNCTION

HST PUMP LPV40 + 40 (SK815-5 – SK815-5 turbo HIGH FLOW)

HYDRAULIC PUMP

10

1 87 2

8

7

5

6

4

1. Piston pump

2. Control piston

3. Suction safety valve

4. Charge safety valve

5. Charge pump

6. Work equipment pump

7. Adjustment screw (Neutral position)

8. Adjustment screw (Max. displacement)

9. Adjustment screw (Pump power control)

10. AS valve

11. Shuttle valve

11 11

3

8 9 9 8

STRUCTURE

This pump is composed of variable swash plate type tan­dem piston pumps (1), control pistons (2), suction safety
valves (3), charge safety valve (4), charge pump (5), work
equipment gear pumps (6), and adjustment screws (7),
(8), (9), AS valve (10), and shuttle valves (11).

RKS00320

10-20

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

HYDRAULIC PUMP

SK815-5 – SK815-5 turbo (STANDARD FLOW AND HIGH FLOW)
SK714-5

FUNCTION

• The rotation and torque transmitted to the pump shaft is converted into hydraulic energy, and pressurized oil is di­scharged according to the load.

• It is possible to change the discharge amount by changing the swash plate angle (plus, zero and minus)

42 56

14

3

(Standard version)

15

1

11

(High-flow version )

A

7

89

12 10 13

15

1. Shaft

2. Case

3. Cradle bearing

4. Rocker cam

5. Control piston

STRUCTURE

• Cylinder block (9) is supported to shaft (1) by a spline
(12), and shaft (1) is supported by the front and rear
bearings (11), (13). The tip of piston (8) is a concave
ball, and shoe (7) is caulked to it to form one unit.
Piston (8) and shoe (7) form a spherical bearing.

• Rocker cam (4) has flat surface A, and shoe (7) is
always pressed against this surface while sliding in a
circular movement.
There is a cradle bearing (3) between cradle and roc­ker cam (4) which is secured to the case.
Rocker cam (4) sways on cradle bearing.

6. Slider

7. Shoe

8. Piston

9. Cylinder block

10. Valve plate

RKS00351

11. Main bearing

12. Spline

13. Sub bearing

14. Charge pump

15. Work equipment pump

• Piston (8) carries out relative movement in the axial
direction inside each cylinder chamber of cylinder
block (9).

• The cylinder block seals the pressurized oil to valve
plate (10) and carries out relative rotation. This sur­face is designed so that the oil pressure balance is
maintained at a suitable level. The oil inside each
cylinder chamber of cylinder block (9) is sucked in and
discharged through valve palte (10).

SK714-5 SK815-5 SK815-5 turbo

10-21

STRUCTURE AND FUNCTION

OPERATION

1. Operation of pump

• Cylinder block (9) rotates together with shaft (1),
and shoe (7) slides on flat surface A.
When this happens, rocker cam (4) moves along
cylindrical surface B, so angle
X of rocker cam (4) and the axial direction of cylinder
block (9) changes. (Angle
te angle).

i) Center line X of rocker cam (4) maintains

swash plate angle
rection of cylinder block (9), and flat surface A
moves as a cam in relation to shoe (7).
In this way, piston (8) slides on t he inside of
cylinder block (9), so a differe nce between vo­lumes E and F is created inside cylinder block
(9). The suction and discharge is carried out by
this difference F-E.
In other words, when cylinder block (9) rotates
and the volume of chamber F becomes smaller,
the oil is discharged during that stroke. On the
other hand, the volume of chamber E becomes
larger, and as the volume becomes bigger, the
oil is sucked in (Fig. 1).

ii) If center line X of rocker cam (4) is in line with

the axial direction of cylinder block (9) (swash
plate angle = 0), the difference between volu­mes E’ and F’ inside cylinder block (9) beco­mes 0, so the pump does not carry out any
suction or discharge of oil (Fig. 2).

iii) Center line X of rocker cam (4) maintains

swash plate angle
rection of cylinder block (9), and flat surface A
moves as a cam in relation to shoe (7).
In this way, piston (8) slides on t he inside of
cylinder block (9), so a differe nce between vo­lumes E” and F” is created inside cylinder
block (9).
The suction and discharge is carried out by this
difference E”-F”. In other words, when cylinder
block (9) rotates and the volume of chamber E”
becomes smaller, the oil is discharged during
that stroke. On the other hand, the volume of
chamber F” becomes larger, and as th e volu­me becomes bigger, the oil is sucked in.
If the direction of swash plate angle is changed,
the relation between discharge and suction of
port PA, PB reverse (Fig. 3).

α between center line

α is called the swash pla-

α in relation to the axial di-

α in relation to the axial di-

α

Fig. 1

Fig. 2

α

HYDRAULIC PUMP

478

X

9

E

PA

PB

1

A

B

4

0

F

E'

9

PA PB

RKS00270

PA PB

RKS00220

F'

8

7

4

X

E"

9

PA

PB

PA PB

RKS00100

10-22

F"

Fig. 3

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

2. Control of discharge amount

• If swash plate angle α becomes larger, the difference between volumes E and F becomes larger and discharge

amount Q increases.

• Swash plate angle

• Control piston (5) moves in a reciprocal movement ( ) according to the signal pressure from pilot line (PPC and
AS valves). This straight line movement is transmitted through slider (6) to rocker cam (4), which is supported by the
cylindrical surface to cradle, slides in a rotating movement in direction ( ).

• On this pump, maximum swash plate angle is

α is changed by control piston (5).

±15.8°..

HYDRAULIC PUMP

5

6

4

3

3

4

RKS00280

RKS00360

• Screw A restricts to the maximum stroke of control piston (i.e. maximum displacement of each pump). When screw
A is tightened, maximum displacement decreases, and when screw A is loosened, maximum displacement in­crease. This screw should be adjusted when the machine doesn’t travel straight or machine maximum speed is little
bit wrong.

• Screw B is the fine adjuster of neutral position of control piston (5). That adjust prevent machine from creep.

B

SK714-5

B

SK815-5 - SK815-5 turbo

A

SK714-5 SK815-5 SK815-5 turbo

A

5

5

A

6

4

6

4

RKS00260

10-23

STRUCTURE AND FUNCTION

HYDRAULIC PUMP

Function of the control piston (on non-induction of pilot signal)

• There are no pressure, so control piston (5) doesn’t move and main pump is on neutral condition.

PPA=0 PPB=0 PPA=0 PPB=0

5 5

Function of the control piston (on induction of pilot signal)

SK714-5

5 5

SK815-5 - SK815-5 turbo

PPA PPBPPA PPB

>>

RKS00230

RKS00240

• When pressurized oil which has the pressure PPA, PPB (PPA>PPB) is led from pilot line (PPC or AS valve), control
piston (5) moves the ( ) direction. Control piston (5) moves the balanced position by spring force and pressure
PPA, PPB.

• If the relation of pressure dimension of PPA, PPB is reversed (i.e. PPA<PPB), control piston moves reversal di­rection.

• On SK714-5, AS valve is not installed, so pressurized oil from PPC valve is directly inducted to control piston.

• On SK815-5 and SK815-5 turbo, AS valve is installed and lower pressure between AS valve output pressure and
PPC pressure is selected by shuttle valve and inducted to control piston (see topic “shuttle valve”).

10-24

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

SUCTION SAFETY VALVE

HYDRAULIC PUMP

5

4

2

3

3

1

1. Charge pump

2. Charge safety valve

3. Suction safety valve
3A. Valve
3B. Rod
3C. Sleeve
3D. Spring
3E. Spring
3F. Plug

4. Piston pump

5. Travel motor

FUNCTION

There are two suction safety valves installed to each HST pump, and they have the following functions:

1) High pressure safety valve

The valve restricts the maximum pressure inside the HST circuit in order to protect the HST circuit.

3A 3B 3C 3D 3F3E

RKS00110

RKS00090

2) Suction safety valve

The valve ensures the flow of the charge oil to the closed HST circuit and prevents the charge oil from flowing into
the pump high pressure side (delivery side).

SK714-5 SK815-5 SK815-5 turbo

10-25

STRUCTURE AND FUNCTION

Actuation when acting as high pressure relief valve
(Valve at piston pump delivery side)

Port A is connected to the piston pump circuit and port B is connected to the charge circuit. The pressurized oil fills
port C through drill hole a of piston (3A). The pressurized oil at high pressure port A fills port D through groove b
between body and valve. Poppet (3A) is in tight contact with valve seat (3C).

HYDRAULIC PUMP

B

• If abnormal pressure is generated in the circuit and the oil pressure at ports A and D reaches to the pressure set by
spring (3D), poppet (3A) is pushed to direction, and oil at port A is relieved to port B to reduce the oil pressure
at port A.

B

3A 3B 3C 3D 3E

a AbC D

3A

RKS00050

10-26

a Ab D

3D

SK714-5 SK815-5 SK815-5 turbo

RKS00060

STRUCTURE AND FUNCTION

Operation when acting as suction safety valve

1) When HST pump delivery is 0.

The HST circuit is closed, and the charge oil does not flow into the HST circuit. Therefore the charge pressurized oil
from the charge pump (1) all passes the charge safety valve (2) and is drained to the pump case.

Travel motor

Travel pump

HYDRAULIC PUMP

2

3

PB PA

RKS00121

3

1

SK714-5 SK815-5 SK815-5 turbo

10-27

STRUCTURE AND FUNCTION

2. When HST pump discharges from port PA

1) Valve at the piston pump delivery side.

When the pressure oil is discharged from port PA of the HST pump (4), port PA becomes the high pressure side.
This pressure oil at port PA flow into port D through the groove b.
When this happen, sleeve (3C) is pushed to direction, because of the difference in area (A1>A2). Therefore the
pressure oil from charge pump is prevented from flowing into HST pump.

HYDRAULIC PUMP

3C b D

PA

PAPB

A2

A1

4

RKS00070

PAPB

1

2) Valve at piston pump suction side

Port PB is at low pressure because port PB is suction side.
And sleeve (3C) is pushed to direction to open body seat portion because of th e difference in area ( A1>A2).
In this way, the charge pressure oil at port B flows into port PB through this clearance to charge to the HST circuit..

3C

PB

RKS00130

10-28

A1

A2

B

RKS00080

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

CHARGE SAFETY VALVE

HYDRAULIC PUMP

2

3

RKS00140

3

1

1. Charge pump

2. Charge safety valve
2A. Valve
2B. Spring
2C. V alve seat
2D. Poppet
2E. Spring
2F. Adjustment screw

3. Suction safety valve

FUNCTION

There is the charge safety v alve installed to the HST pump.
The charge safety valve restricts the maximum pressure inside the charge circuit in order to protect the charge circuit.

2A 2B 2G 2C 2D 2E 2F

RKS00040

SK714-5 SK815-5 SK815-5 turbo

10-29

STRUCTURE AND FUNCTION

FUNCTION

•Port A is connected to the charge circuit.
Port B is connected to the tank drain circuit.
The pressurized oil fills port C through orifice a in valve (2A).
Poppet (2D) is in tight contact with valve seat (2C)

C

2A 2C 2D

1

A

HYDRAULIC PUMP

2E

a

• If abnormal pressure is generated in the circuit or the shuttle valve of HST motor is at neutral and the oil pressure at
ports A and C reaches the pressure set by spring (2E), poppet (2D) is pushed to direction, and oil at C is relieved
to port B and pressure of the oil at C reduce.

A

B

C

2D 2E2A

RKS00020

RKS00010

B

• When the pressure of the oil at port C goes down, a differential pressure is occured between ports A and C because
of orifice a in valve (2A).
Valve (2A) is pushed to direction by oil pressure at port A, and oil at port A is relieved to port B.
In this way, the pressure in the charge circuit is prevented from going any higher.

10-30

2A

A

a

B

C

RKS00030

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

CHARGE PUMP

HYDRAULIC PUMP

1

2

3

6

7

1. Slide plate

2. Coupling

3. Shaft

4. Outer ring

5. Case

6. Inner roter

7. Outer roter

4

5

RKS00150

FUNCTION

• HST charge pump is built-in the HST pump and driven
with HST pump at the same time.

• Discharged oil is delivered to AS valve and charge sa­fety valve. (AS valve is only installed SK815-5 and
SK815-5 turbo).

• Charge pump sucks oil from hydraulic tank.

SPECIFICATIONS

• Type: trochoid pump

• Theoletical delivery: 25 cm³/rev

SK714-5 SK815-5 SK815-5 turbo

10-31

STRUCTURE AND FUNCTION

FUNCTION

Discharge port

A

HYDRAULIC PUMP

7 6

B

2

Discharge side

Suction side

A

Suction port

• Charge pump is connected to HST pump shaft by coupling (2), so inner roter (6) and outer roter (7) rotate.

• When inner roter (6) and outer roter (7) rotate, capacity of A increase and oil is sucked, and capacity of B decrease
and oil discharge.

A

RKS00161

10-32

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

ANTI ENGINE-STALL CONTROL VALVE (AS VALVE)

4

HYDRAULIC PUMP

3

1. AS valve
1A. Nut
1B. Screw
1C. Spring
1D. Spring
1E. Spring
1F. Valve
1G. Valve
1H. Nut
1L. Screw

2. Charge pump

3. Orifice

4. Charge safety valve

5. Engine

1A 1B 1C 1F 1D 1E

FUNCTION

• The AS valve is attached on the main piston pump. It
reduces pressure for pump swash plate control from
charge circuit.

• The AS valve outputs pressure correspond with en­gine revolution.

1G 1H1L

E

2

5

RKS00170

SK714-5 SK815-5 SK815-5 turbo

10-33

STRUCTURE AND FUNCTION

OPERATION

HYDRAULIC PUMP

3

2

B

A

5

E

1C 1D 1G

D

G

C

• The oil from the charge pump (2) that rotates with the engine flows through a orifice (3) that is installed in the main
piston pump. And the oil always flows to pump charge circuit.

• Charge pump (2) is fixed capacity pump, so that discharge flow is proportionate to engine rotation speed. With the
oil from the charge pump (2) passed through the orifice, differential pressure is generated at port A and port B. This
differential pressure actuates the differential pressure sensing valve (1G) and makes hydraulic force F.

• By the hydraulic force F, the differential pressure sensing valve (1G) is moved direction.
That makes a change of spring (1D) load.
In port C, the AS valve output pressure that is balanced with spring (1C) and (1D) load is generated by reducing from
charge pressure of port G.
So the AS valve outputs pressure correspond with charge flow that is changed by engine (5) revolution.

E

F

RKS00180

10-34

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

SHUTTLE VALVE

HYDRAULIC PUMP

1. Valve

2. Plug

3. Cover

123

RKS00200

FUNCTION

• The shuttle valves are installed in covers of pump
swash plate control pistons. They select lower pres­sure either travel PPC pressure or AS valve pressure,
and output to pump swash plate control pressure.

D

B

A

F2

F1

C

1

E

RKS00210

OPERATION

•Port C is connected to port A (Travel PPC pressure inlet port). And hydraulic force F1 by travel PPC pressure ac-
tuates the valve (1).

• And port D is connected to port B (AS pressure inlet port). Hydraulic force F2 by AS valve pressure actuates the val­ve (1).

• By the hydraulic force F1 and F2, the shuttle valve selects lower pressure either PPC pressure or AS valve pressure.
It outputs lower pressure of them from port E to control pump swash plate.

SK714-5 SK815-5 SK815-5 turbo

10-35

STRUCTURE AND FUNCTION

CONTROL VALVE (3-SPOOL)

SK714-5 – SK815-5 – SK815-5 turbo STANDARD

B

D

B3

B2

PA3

G

A3

A2

CONTROL VALVE

A

PB3

G

F

PA2

E

PA1

B1

C

TS

T

B

A1

P1

F

PB2

E

PB1

C

A

D

RKS00250

P1: from gear pump
T: to tank
Ts: to tank
A1: to lift arm cylinder (head side)
A2: to bucket cylinder (head side)

10-36

A3: to attachment port
B1: to lift arm cylinder (bottom side)
B2: to bucket cylinder (bottom side)
B3: to attachment port

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

CONTROL VALVE

4

4

9

5

8

3

2

7

6

1

Section A - A

AA

BB

10

Section B- B

12

AA

Section C - C

1. Main relief valve

2. Stop plug (lift arm bottom side)

3. Suction valve (bucket bottom side)

4. Stop plug for individual relief valve

5. Suction valve (lift arm head side)

6. Series - parallel circuit switching valve

7. Spool (lift arm)

SK714-5 SK815-5 SK815-5 turbo

BB

11

Section AA-AA

8. Spool (bucket)

9. Spool (attachment)

10. Flow divider

11. Check valve (circulating circuit)

12. Combination circulating valve

13. Leveling circulating valve

13

Section BB-BB

RKS00521

10-37

STRUCTURE AND FUNCTION

CONTROL VALVE

9

4

5

8

9

6

3

2

1

12

Section D - D

11

7

10

2

Section E - E

15 15

7

14

13

1. Unload valve

2. Pressure compensation valve F (lift arm)

3. Pressure compensation valve F (bucket)

4. Pressure compensation valve F (attachment)

5. Pressure compensation valve R (attachment)

6. Pressure compensation valve R (bucket)

7. Pressure compensation valve R (lift arm)

8. Spool (lift arm)

9. Suction valve

3

Section F - F

6

10-38

4

Section G - G

10. Shuttle valve

11. Spool (bucket)

12. Suction valve

13. Shuttle valve

14. Spool (attachment)

15. Stop plug for individual relief valve

★ F: Flow control valve

R: Pressure reducing valve

SK714-5 SK815-5 SK815-5 turbo

5

RKS00671

STRUCTURE AND FUNCTION

CONTROL VALVE (4-SPOOL)

SK815-5 – SK815-5 turbo SUPER HIGH-FLOW

CONTROL VALVE

C

B

PA3

B4

B3

A4

A3

Pi

A

JJ

A2
A1

H

PB3

G

F

PB2

E

PB1

D

A

H

G

F

PA2

E

B2

PA1

B1

D

TS

T

P1

B

C

P2

P1. from gear pump
P2: from gear pump
T: to tank
Ts: to tank
Pi2: From solenoid valve group ST2 (S port)
A1: to lift arm cylinder (head side)
A2: to bucket cylinder (head side)

SK714-5 SK815-5 SK815-5 turbo

RKS00370

A3: to attachment port
A4: to High - Flow port
B1: to lift arm cylinder (bottom side)
B2: to bucket cylinder (bottom side)
B3: to attachment port
B4: to High-Flow attachment port

10-39

STRUCTURE AND FUNCTION

CONTROL VALVE

4

4

4

4

3

2

5

10

1

9

Section A - A

8

1. Main relief valve

2. Stop plug (lift arm bottom side)

3. Suction valve (bucket bottom side)

4. Stop plug for individual relief valve

5. Float valve

10-40

7

6

Section B - B

6. Series - parallel circuit switching valve

7. Spool (lift arm)

8. Spool (bucket)

9. Spool (attachment)

10. Spool (High-Flow)

SK714-5 SK815-5 SK815-5 turbo

RKS00382

STRUCTURE AND FUNCTION

CONTROL VALVE

AA

BB

6

7

AA

8

Section D - D

BB

5

9

4

10

11

3

2

1

Section C - C

1. Unload valve

2. Pressure compensation valve F (lift arm)

3. Pressure compensation valve F (bucket)

4. Pressure compensation valve F (attachment)

5. Pressure compensation valve F (High Flow)

6. Check valve (for High - Flow joining circuit)

7. Pressure compensation valve R (High Flow)

8. Pressure compensation vavle R (attachment)

9. Pressure compensation valve R (bucket)

13

Section BB-BB

14

Section AA-AA

10. Pressure compensation valve R (lift arm)

11. Combination circulating valve

12. Leveling circulating valve

13. Flow-divider

14. Check valve (circulating circuit)

★ F: Flow control valve

R: Pressure reducing valve

12

RKS00701

SK714-5 SK815-5 SK815-5 turbo

10-41

STRUCTURE AND FUNCTION

2 4

CONTROL VALVE

3

8

1

Section E - E

7

5

5

11

10

6

19

16

16

12913

Section F - F

15

5

18

Section H - H

20

21

Section J - J

1. Pressure compensation valve F (lift arm)

2. Spool (lift arm)

3. Stop plug

4. Float valve

5. On - off solenoid

6. Spool (float)

7. Pressure compensation valve F (lift arm)

8. Shuttle valve

9. Pressure compensation valve R (bucket)

10. Spool (bucket)

11. Suction valve

12. Pressure compensation valve R (bucket)

22

16

5

14

Section G - G

13. Shuttle valve

14. Pressure compensation valve F (attachment)

15. Spool (attachment)

16. Stop plug for individual relief valve

17. Pressure compensation valve R (attachment)

18. Pressure compensation valve F (High Flow)

19. Spool (High - Flow)

20. Pressure compensation valve R (High Flow)

21. Check valve (High - Flow joining circuit)

22. Spool (High Flow joining)

★ F: Flow control valve

R: Pressure reducing valve

17

16

RKS00681

10-42

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

CLSS

1. OUTLINE

Features

• CLSS stands for Closed center Load Sensing System, and has the followings characteristics.
1 - Controlability, not influenced by load.
2 - Controllable digging force at fine control range.
3 - Easy simultaneous operation by spool opening proportional flow dividing function.

2. PRESSURE COMPENSATION CONTROL

A valve (pressure compensation valve) is installed to the inlet port side of the control valve to balance the load.
When there is compound operation of the actuators, this valve acts to make pressure difference
stream flow (inlet port) and downstream flow (outlet port) of the notch of each spool.
In this way, the flow of oil from the pump is divided in proportion to area of opening S1 and S2 of each valve.

∆P constant for the up-

CLSS

Load

W

Actuator

∆ P ∆ P

S1

Pressure
compensation
valve

Pressure
compensation
valve

Load

W

Actuator

S1

SK714-5 SK815-5 SK815-5 turbo

Pump

RKS00691

10-43

STRUCTURE AND FUNCTION

CLSS

3. OPERATION FOR EACH FUNCTION AND VALVE

Features

• The small capacity gear pump keeps high speed movement because lift arm and the bucket circuit are connected
in a series circuit.

• The control valve has built in self leveling function.

• If loading pressure of bucket becomes beyond a certain value, the lift arm and the bucket circuits automatically chan­ge to parallel circuit to keep strong digging force.

• The lift arm, attachment and High-flow section are connected in a parallel circuit and it has pressure compensa­tioning function each section.

• During individual operations, attachment High-flow keep individual demand flow rate.
However during compound operations, they are divided in the proportion of 1 to 9 and keep High-flow section flow
rate. (SK815-5 and SK815-5 turbo has only Super-flow specification.)

Hydraulic circuit diagram and names of val ve s

P2

13

P1

Ls

A4

Optional equipment
High-flow

B4

Raise arm

Pa1

Dump bucket

11

9

6

A3

Optional equipment

B3

Pa3

Pa3

Port

5

A2

B2

Pa2

11

Pa2

Curl bucket

Bucket cylinder

4

A1

B1

Raise cylinder

7

8

3

12

10

1

2

Pa1

Lower arm

RKS00751

1. Unload valve

2. Main relief valve

3. Pressure compensation valve (lift arm)

4. Pressure compensation valve (bucket)

5. Pressure compensation valve (attachment)

6. Pressure compensation valve (High - Flow)

7. Float valve

10-44

8. Leveling circulating valve

9. Combination circulating valve

10. Flow divider

11. Shuttle valve

12. Check valve (circulating circuit)

13. High - Flow joining spool

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

3.1 SERIES CIRCUIT
Function

• Return flow rate from the lift arm is recirculated to the bucket.

CLSS

2

a

3

d

4

b

c

F

P1

Q1

P2

D

A

B

C

Q2

1

5

6

E

Operation

When the lift arm raise and the bucket dump are operated at the same time.

• The lift arm spool (1) strokes fully and the bucket spool (2) stokes by half.

• When this happens, notch (a ) doesn’t open, so all flow rate from pump supplies to the lift arm raise.

• The lift arm and the bucket PPC pressure are sent by passage E and F.
Then the leveling circulating valve (3) and the combination circulating valve (4) stroke fully.

• Return flow rate from the lift arm cylinder passes through passage A.
Then it is divided to passage B and C, by the leveling circulating valve (4) and the combination circulating valve (3).

• When this happens, the flow divider (5) is operated as P1=P2, so flow rate (Q1, Q2) is divided to passage B and C
in proportion to the area of opening of not ch (b) and (c) as below expression.

Q1:Q2= (notch (b) + notch (d) ): notch (C)
Q1= flow rate flows to B, Q2= flow rate flows to C

• Q1 passes through the check valve (6) and then supplies to the bucket cylinder.

SK714-5 SK815-5 SK815-5 turbo

RKS00720

10-45

STRUCTURE AND FUNCTION

3.2 SELF LEVELING FUNCTION
Function

• When the only lever of the lift arm raise is operated, the lift arm raise and the bucket dump are worked.
When this happens, the work equipment can raise with constant bucket bottom angle. (Only the lift arm raise)..

CLSS

2

a

3

d

4

b

c

F

P1

Q1

P2

D

A

B

C

Q2

1

5

6

E

Operation

When the lift arm raise is operated individually.

• The lift arm spool (1) strokes fully and the bucket spool strokes by half.

• When this happens, notch (a) doesn’t open, so all flow rate from pump supplies to the lift arm raise.

• The lift arm raise PPC pressure is sent by passage E.
Then the leveling circulating valve strokes fully.

• Return flow rate from the lift arm cylinder passes through passage A.
Then it is divided to passage B and C, by the leveling circulating valve (3).

• When this happens, the flow divider (5) is operated as P1=P2, so flow rate (Q1, Q2) is divided to B and C in prportion
to the area of opening of notch (b) and (c) as below expression.
Q1:Q2= notch (b):notch (C)

• Q1 passes through the check valve (6) and then supplies to the bucket cylinder.

10-46

SK714-5 SK815-5 SK815-5 turbo

RKS00720

STRUCTURE AND FUNCTION

3.3 THE FUNCTION TO SWITCH SERIES CIRCUIT TO PARALLEL CIRCUIT
Function

• (1) Low bucket load: Series circuit

• (2) High bucket load: Parallel circuit

• Depend on bucket load, a circuit can change automatically as above.
Then the machine gets high speed and strong digging power.

CLSS

2

a

3

d

F

H

4

b

A

P1

Q1

c

P2

D

BC

1

Q2

f

SK714-5 SK815-5 SK815-5 turbo

E

P3

5

6

e

G

7

RKS00730

10-47

STRUCTURE AND FUNCTION

CLSS

Operation

When the lift arm raise and the bucket digging are operated at the same time.

• The lift arm spool (1) and the bucket spool (2) stroke fully.

• When this happens, the bucket digging PPC pressure is sent by passage H.
Then the combination circulating valve (3) strokes fully to the right and also the lift arm raise PPC pressure is sent
by passage E.
Then the leveling circulating valve (4) strokes fully to the left.

• Return flow rate from the lift arm cylinder passes through passage A.
Then it is divided to passage B and C, by the leveling circulating valve (4) and the combination circulating valve (3).

• When this happens, the flow divider (5) is operated as P1=P2, so flow rate (Q1, Q2) is divided to passage B and C
in proportion to the area of opening as below expression.

Q1:Q2= (notch (b) + notch (d)): notch (C)
Q1= flow rate flows to B
Q2=flow rate flows to C

• If the bucket load becomes beyond a certain valve by influences of digging, the series-parallel switching valve (7)
strokes to the right.
Then it passes thorough passage G by opening notch (e).
And then the spring chamber of flow divider (5) is connected to tank.

• As a result, flow divider strokes fully to the right, and P2=T
Return flow rate from the lift arm is connected with tank totally, and Q1=0L/min.

• When this happens, notch (f) of the lift arm spool and notch (a) of the bucket spool open, so the lift arm and the bucket
become parallel circuit (CLSS).
And flow rate of the lift arm raise (Q3) and teh buck et digging flow rate are divided as below expression.
Q3:Q4= notch (f): notch (a)

10-48

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

CLSS

3.4 PRESSURE COMPENSATION VALVE
Function

• During compound operations, if the load pressure becomes lower than the other actuator and the oil flow tries to in­crease, compensation is received. (When this happens, the other actuator being used for compund operation (right
side) is at a higher load than the actuator on this side (left side))..

W

A

W

A

T

PPA

a

PLS1

PPA

a

PA

1

PA

2

PP

Operation

• If the load pressure of the other actuator (right side) becomes higher during compound operations, the oil flow in ac­tuator circuit A on this side (left side) tries to increase.

• If this happens, the LS pressure PLS of the other actuator acts on spring chamber PLS1, and reducing valve (1) and
flow control valve (2) are pushed to the left in the direction of the arrow.

• Flow control valve (2) throttles the area of opening between pump circuit PP and spool upstream PPA, and pressure
loss is generated between PP and PPA.

• Flow control valve (2) and reducing valve (1) are balanced in position where the difference in pressure between PLS
and PA acting on both ends of reducing valve (2) and the pressure loss between PP and PPA on both sides of flow
control valve (2) are the same.

• In this way, the pressure difference between upstream pressure PPA and down stream pressure PA of both spools
used during compund operations is the same, so the pump flow is divided in prioportion to the area of opening of
notch a of each spool.

PLS

RKS00740

SK714-5 SK815-5 SK815-5 turbo

10-49

STRUCTURE AND FUNCTION

3.5 DIVIDING FUNCTION (1:9) (Only Super-Flow specification for SK815-5 and SK815-5 turbo)
Function

1 When each section is operated individually

Attachment: 60L/min
High-Flow attachment: 100L/min

2 When standard attachment and high flow attachment are operated at the same time

1:9=attachment: High-Flow

1

2

3

CLSS

A

Attachment section High-flow section

RKS00711

Operation

1 When each section is operated individually

• Attachment spool (1) and High-Flow spool (3) stroke fully and individually, therefore they keep demand flow rate in­dividually.
Attachment: 60L/min
High-Flow: 100L/min

2 When attachment and High-Flow are operated at the same time.

• High-Flow attachment PPC pressure passes through passage A, is sent to retainer (2) and makes retainer (2) stroke
to the left.

• When this happens, attachment spool (1) can stroke by half.

• As a result, flow rate of attachment and High-Flow are divided as below expression.
Attachment: High-Flow= 1:9

• Therefore flow rate of high flow is kept.

10-50

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

SOLENOID VALVE

SOLENOID VALVE GROUP ST1

(SERVOCONTROL - PARKING BRAKE - 2nd SPEED)

SOLENOID VALVE

1

2

3

P

Z

T

A

B

C

FUNCTION

1. 2nd speed

2. Servocontrol

3. Parking brake

SK714-5 SK815-5 SK815-5 turbo

S

View Z

A Port – To travel motors (PP1 port)
B Port – To PPC valve
C Port – To travel motors (PP2 port)
P Port – From hydraulic pump (E1 port)
T Port – To hydraulic tank
S Port – To accumulator

RKS01151

10-51

STRUCTURE AND FUNCTION

SOLENOID VALVE ST2

HIGH-FLOW CONTROL

S

SOLENOID VALVE

T

P2

T Port – To hydraulic tank
P1 Port – From control valve (PA3 port)
P2 Port – From control valve (PB3 port)
S Port – To control valve (Pi2 port)

P2

RKS01140

10-52

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

ACCUMULATOR

ACCUMULATOR

TECHNICAL DATA

Servocontrol feed unit

• Nominal volume: 0.35

• Pre-loading: 8 bar

• Working pressure: 25 – 27 bar

ᐉ

A

1

B

RKS01650

FUNCTION

• An elastic rubber bag (1) containing nitrogen is fitted
inside the accumulator to maintain oil pressure in the
circuit to which the accumulator is connected.

OPERATION

• When the engine is running the chamber A of the rub­ber bag (1) (containing nitrogen) is compressed by oil
under pressure coming from line B.

• If the oil under in line B falls below the maximum ca­libration pressure (even after intensive use), the rub­ber bag (1) will expand due to pressure from the
nitrogen it.

SK714-5 SK815-5 SK815-5 turbo

10-53

STRUCTURE AND FUNCTION

PATTERN CHANGE VALVE (OPTIONAL)

PATTERN CHANGE VALVE (OPTIONAL)

P out 4

OPT ISO

View Z

P out 6

P out 1

6

1

2

3

5

4

P out 3

P out 5

P out 2

Z

P out 4
P out 3
P out 2
P out 1
P out 5
P out 6

Pout 4

Pout 3
Pout 2
Pout 1
Pout 5
Pout 6

P in 4
P in 3
P in 2
P in 1
P in 5
P in 6

P in 4

P in 3
P in 2
P in 1
P in 5
P in 6

Pin 1. From L.H. PPC valve (P4 port)
Pin 2. From L.H. PPC valve (P1 port)
Pin 3. From L.H. PPC valve (P3 port)
Pin 4. From L.H. PPC valve (P2 port)
Pin 5. From R.H. PPC valve (P1 port)
Pin 6. From R.H. PPC valve (P2 port)

ISO PATTERNOPTIONAL

PATTERN

OPTIONAL

ISO PATTERN

PATTERN

B

P in 4

4

P in 6

Pout 1. To hydraulic pump (DA1 port)
Pout 2. To hydraulic pump (DA2 port)
Pout 3. To hydraulic pump (DB1 port)
Pout 4. To hydraulic pump (DB2 port)
Pout 5. To control valve (PA1 port)
Pout 6. To control valve (PB1 port)

6

2

P in 2

P in 1

1

P in 5

5

3

AA

P in 3

B

RKS00661

10-54

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

PATTERN CHANGE VALVE (OPTIONAL)

C

E

F

G

D

C

F

D

E

3

G

7

Section A - A

7

5

Section H - H

4

3

1

H

2

6

H

Section B - B

Section E - E

Section E - E

Section C - C

Section D - D

1. Lever

2. Rotor

3. Valce seat

4. Ball

SK714-5 SK815-5 SK815-5 turbo

Section F - F

Section G - G

5. Upper cover

6. Lower cover

7. Pin lock

Section F - F

Section G - G

RKS00651

10-55

STRUCTURE AND FUNCTION

OPERATION

PATTERN ISO

P out 4

P out 3

P out 2

P out 1

P out 5

P out 6

PA1

PB1

A1

B1

B2

A2

P in 4

P in 3

P in 2

P in 1

P in 5

P in 6

PATTERN CHANGE VALVE (OPTIONAL)

P1

LEFT

STEERING

P2

P3

P4

P

T

P1

P2

P3

REVERSE

ARM

RAISE

RIGHT

STEERING

FRONT

BUCKET

DUMP

FORWARD

ARM

DOWN

PATTERN OPTIONAL

P out 4

P out 3

P out 2

P out 1

P out 5

P out 6

PA1

A1

B1

B2

A2

P in 4

P in 3

P in 2

P in 1

P in 5

P in 6

BUCHET

P4

P

T

P1

P2

P3

P4

P

T

L.H. REVERSE

CURL

ARM

RAISE

ARM

DOWN

RKS00921

L.H. FORWARD

FRONT

P1

BUCKET

CURL

P2

P3

R.H. REVERSE

R.H. FORWARD

PB1

10-56

BUCKET

P4

P

T

DUMP

RKS00931

SK714-5 SK815-5 SK815-5 turbo

PAGE INTENTIONALLY

LEFT BLANK

STRUCTURE AND FUNCTION

R.H. PPC VALVE (STANDARD)

EQUIPMENT CONTROL

P2 P4

B

R.H. PPC VALVE (STANDARD)

P1P3

B

A

C

P1 port - To control valve (PA1 port)
P2 port - To control valve (PB1 port)
P3 port - To control valve (PA2 port)
P4 port - To control valve (PB2 port)
P port - From solenoid valve group ST1 (B port)
T port - To hydraulic tank

EE

T

C

A

FUNCTION

P1 Lower arm
P2 Raise arm
P3 Curl bucket
P4 Dump bucket

DD

P

RKS00800

10-58

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

6

R.H. PPC VALVE (STANDARD)

5

7

4

8

3

9

2

10

1

Section A - A

Section B - B

1. Spool

2. Metering spring

3. Centering spring

4. Piston

5. Disc

Section D - D

Section C - C

Section E - E

RKS00811

6. Nut

7. Joint

8. Cover

9. Stopper

10. Body

SK714-5 SK815-5 SK815-5 turbo

10-59

STRUCTURE AND FUNCTION

FUNCTION

1. NEUTRAL
Ports P1 and P2 of the PPC valve are connected to
drain chamber D through fine control hole f in spool
(1). (Fig. 1)

R.H. PPC VALVE (STANDARD)

D

f

T

P

2. During fine control (NEUTRAL → fine control)

• When piston (4) starts to be pushed by disc (5), re­tainer (9) is pushed; spool (1) is also pushed by me­tering spring (2), and moves down.
When this happens, fine control hole f is shut off
from drain chamber D, and at almost the same time,
it is connected to pump pressure chamber PP, so pi­lot pressure oil from the control pump passes throu­gh fine control hole f and goes to port P1.
When the pressure at port P1 becomes higher, spo­ol (1) is pushed back and fine control hole f is shut off
from pump pressure chamber PP.
At almost the same time, it is connected to drain
chamber D to releas e the pressure at port P1.
When this happens, spool (1) moves up or down so
that the force of metering spring (2) is balanced with
the pressure at port P1. The relationship in the po­sition of spool (1) and body (10) (fine control hole f is
at a point midway between drain hole D and pump
pressure chamber PP) does not change even if the
pressure at port P1 becomes max.
Therefore, metering spring (2) is compressed pro­portionally to the amount of movement of the control
lever, so the pressure at port P1 also rises in pro­portion to the travel of the control lever. (Fig. 2)

Fig. 1

Fig. 2

1

P2P1

RKS00820

5

4

9
3
2

f

P

1

P

D

T

PP

10

2P1

RKS00830

10-60

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

3. During fine control (when the lever is returned)

(fine control → neutral)

When disc (5) starts to be returned, spool (1) is pu­shed up by the force of centering spring (3) and the
pressure at port P1.
When this happens, fine control hole f is connected
to drain chamber D and the pressure oil at port P1 is
released.
If the pressure at port P1 drops too far, spool (1) is
pushed down by metering spring (2), and fine con­trol hole f is shut off from drain chamber D.
At almost the same time, it is connected to pump
pressure chamber PP, and the pump pressure is
supplied until the pressure at port P1 recovers to a
pressure that corresponds to the lever position.
(Fig. 3).

Fig. 3

R.H. PPC VALVE (STANDARD)

5

4

9
3

2

f

P

1

P

D

T

f

PP

2P1

RKS00840

SK714-5 SK815-5 SK815-5 turbo

10-61

STRUCTURE AND FUNCTION

R.H. PPC VALVE (PATTERN CHANGE) (OPTIONAL)

R.H. PPC VALVE (PATTERN CHANGE) (OPTIONAL)

EQUIPMENT AND TRAVEL CONTROL

P2 P4

P1P3

B

B

A

C

Attacco P1- To pattern change valve (Pin 5 port)
Attacco P2- To pattern change valve (Pin 6 port)
P3 port - To control valve (PA2 port)
P4 port - To control valve (PB2 port)
P port - From solenoid valve group ST1 (B port)
T port - To hydraulic tank

EE

T

C

A

FUNCTION
ISO PATTERN: P1 Lower arm

P2 Raise arm
P3 Curl bucket
P4 Dump bucket

OPTIONAL PATTERN:

P1 R.H. travel forward

P2

R.H. travel
P3 Curl bucket
P4 Dump bucket

DD

P

RKS00800

reverse

10-62

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

6

R.H. PPC VALVE (PATTERN CHANGE) (OPTIONAL)

5

7

4

8

3

9

2

10

1

Section A - A

Section B - B

1. Spool

2. Metering spring

3. Centering spring

4. Piston

5. Disc

Section D - D

Section C - C

Section E - E

RKS00811

6. Nut

7. Joint

8. Cover

9. Stopper

10. Body

SK714-5 SK815-5 SK815-5 turbo

10-63

STRUCTURE AND FUNCTION

FUNCTION

1. NEUTRAL
Ports P1 and P2 of the PPC valve are connected to
drain chamber D through fine control hole f in spool
(1). (Fig. 1)

R.H. PPC VALVE (PATTERN CHANGE) (OPTIONAL)

D

f

T

P

2. During fine control (NEUTRAL → fine control)

• When piston (4) starts to be pushed by disc (5), re­tainer (9) is pushed; spool (1) is also pushed by me­tering spring (2), and moves down.
When this happens, fine control hole f is shut off
from drain chamber D, and at almost the same time,
it is connected to pump pressure chamber PP, so pi­lot pressure oil from the control pump passes throu­gh fine control hole f and goes to port P1.
When the pressure at port P1 becomes higher, spo­ol (1) is pushed back and fine control hole f is shut off
from pump pressure chamber PP.
At almost the same time, it is connected to drain
chamber D to releas e the pressure at port P1.
When this happens, spool (1) moves up or down so
that the force of metering spring (2) is balanced with
the pressure at port P1. The relationship in the po­sition of spool (1) and body (10) (fine control hole f is
at a point midway between drain hole D and pump
pressure chamber PP) does not change even if the
pressure at port P1 becomes max.
Therefore, metering spring (2) is compressed pro­portionally to the amount of movement of the control
lever, so the pressure at port P1 also rises in pro­portion to the travel of the control lever. (Fig. 2)

Fig. 1

Fig. 2

1

P2P1

RKS00820

5

4

9
3
2

f

P

1

P

D

T

PP

10

2P1

RKS00830

10-64

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

3. During fine control (when the lever is returned)

(fine control → neutral)

When disc (5) starts to be returned, spool (1) is pu­shed up by the force of centering spring (3) and the
pressure at port P1.
When this happens, fine control hole f is connected
to drain chamber D and the pressure oil at port P1 is
released.
If the pressure at port P1 drops too far, spool (1) is
pushed down by metering spring (2), and fine con­trol hole f is shut off from drain chamber D.
At almost the same time, it is connected to pump
pressure chamber PP, and the pump pressure is
supplied until the pressure at port P1 recovers to a
pressure that corresponds to the lever position.
(Fig. 3).

R.H. PPC VALVE (PATTERN CHANGE) (OPTIONAL)

5

4

9
3

2

f

P

1

P

Fig. 3

D

T

f

PP

2P1

RKS00840

SK714-5 SK815-5 SK815-5 turbo

10-65

STRUCTURE AND FUNCTION

L.H. PPC VALVE (STANDARD)

TRAVEL CONTROL

P2 P4

B

L.H. PPC VALVE (STANDARD)

P1P3

A

P1 port - To hydraulic pump (DA2 port)
P2 port - To hydraulic pump (DB2 port)
P3 port - To hydraulic pump (DA1 port)
P4 port - To hydraulic pump (DB1 port)
P port - From solenoid valve group ST1
T port - To hydraulic tank

E

C

B

T

P

E

FF

DD

C

RKS00860

A

FUNCTION

L.H. travel forward

P1
P2

L.H. travel reverse

P3

R.H. travel forward

P4

R.H. travel reverse

★ When acting control lever, two ports are pressurized

contemporarily (i.e.: travel forward pressurize P1 and
P3 ports).

10-66

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

6

L.H. PPC VALVE (STANDARD)

5

7

4

8

3

9

2

10

1

Section A - A

Section B - B

1. Spool

2. Metering spring

3. Centering spring

4. Piston

5. Disc

6. Nut

7. Joint

Section C - C

Section E - E

Section D - D

G

Section F - F

Section G - G

8. Cover

9. Stopper

10. Body

11. Plug

12. Ball

13. Seat

14. Body (for shuttle valve)

11

12

13

G

14

RKS00871

SK714-5 SK815-5 SK815-5 turbo

10-67

STRUCTURE AND FUNCTION

FUNCTION

1. NEUTRAL
Ports P1 and P2 of the PPC valve are connected to
drain chamber D through fine control hole f in spool
(1). (Fig. 1)

2. During fine control (NEUTRAL → fine control)

• When piston (4) starts to be pushed by disc (5), re­tainer (9) is pushed; spool (1) is also pushed by me­tering spring (2), and moves down.
When this happens, fine control hole f is shut off
from drain chamber D, and at almost the same time,
it is connected to pump pressure chamber PP, so pi­lot pressure oil from the control pump passes throu­gh fine control hole f and goes from port P1.
When the pressure at port P1 becomes higher, spo­ol (1) is pushed back and fine control hole f is shut off
from pump pressure chamber PP.
At almost the same time, it is connected to drain
chamber D to releas e the pressure at port P1.
When this happens, spool (1) moves up or down so
that the force of metering spring (2) is balanced with
the pressure at port P1. The relationship in the po­sition of spool (1) and body (10) (fine control hole f is
at a point midway between drain hole D and pump
pressure chamber PP) does not change even if the
pressure at port P1 becomaes max.
Therefore, metering spring (2) is compressed pro­portionally to the amount of movement of the control
lever, so the pressure at port P1 also rises in pro­portion to the travel of the control lever. (Fig. 2)

Fig. 1

Fig. 2

L.H. PPC VALVE (STANDARD)

D

f

T

P

1

(P3)

P2P1

(P4)

RKS00890

5

4

3

2

f

P

1

D

T

PP

10

P2P1

RKS00900

A

Distributore

B

10-68

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

3. During fine control (when the lever is returned)

(fine control → neutral)

When disc (5) starts to be returned, spool (1) is pu­shed up by the force of centering spring (3) and the
pressure at port P1.
When this happens, fine control hole f is connected
to drain chamber D and the pressure oil at port P1 is
released.
If the pressure at port P1 drops too far, spool (1) is
pushed down by metering spring (2), and fine con­trol hole f is shut off from drain chamber D.
At almost the same time, it is connected to pump
pressure chamber PP, and the pump pressure is
supplied until the pressure at port P1 recovers to a
pressure that corresponds to the lever position.
(Fig. 3).

L.H. PPC VALVE (STANDARD)

5

4

3

2

f

P

1

D

T

f

PP

Fig. 3

P1

P2

RKS00880

SK714-5 SK815-5 SK815-5 turbo

10-69

STRUCTURE AND FUNCTION

L.H. PPC VALVE - PATTERN CHANGE (OPTIONAL)

L.H. PPC VALVE - PATTERN CHANGE (OPTIONAL)

WORK EQUIPMENT AND TRAVEL CONTROL

P2 P4

P1P3

B

A

P1 port - To pattern change valve (Pin 1 port)
P2 port - To pattern change valve (Pin 2 port)
P3 port - To pattern change valve (Pin 3 port)
P4 port - To pattern change valve (Pin 4 port)
P port - From solenoid valve group ST1
T port - To hydraulic tank

C

B

EE

T

C

A

FUNCTION
ISO PATTERN: P1

P2
P3 L.H.
P4 R.H.

OPTIONAL PATTERN:

P2
P3 Raise arm
P4 Lower arm

DD

P

RKS00800

Travel forward
Travel reverse

travel

travel

P1 L.H. travel forward

L.H. travel reverse

10-70

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

6

L.H. PPC VALVE - PATTERN CHANGE (OPTIONAL)

5

7

4

8

3

9

2

10

1

Section A - A

Section B - B

1. Spool

2. Metering spring

3. Centering spring

4. Piston

5. Disc

6. Nut

Section D - D

Section C - C

Section E - E

RKS00811

7. Joint

8. Cover

9. Stopper

10. Body

SK714-5 SK815-5 SK815-5 turbo

10-71

STRUCTURE AND FUNCTION

FUNCTION

1. NEUTRAL
Ports P1 and P2 of the PPC valve are connected to
drain chamber D through fine control hole f in spool
(1). (Fig. 1)

.

L.H. PPC VALVE - PATTERN CHANGE (OPTIONAL)

D

f

T

P

2. During fine control (NEUTRAL → fine control)

• When piston (4) starts to be pushed by disc (5), re­tainer (9) is pushed; spool (1) is also pushed by me­tering spring (2), and moves down.
When this happens, fine control hole f is shut off
from drain chamber D, and at almost the same time,
it is connected to pump pressure chamber PP, so pi­lot pressure oil from the control pump passes throu­gh fine control hole f and goes from port P1.
When the pressure at port P1 becomes higher, spo­ol (1) is pushed back and fine control hole f is shut off
from pump pressure chamber PP.
At almost the same time, it is connected to drain
chamber D to releas e the pressure at port P1.
When this happens, spool (1) moves up or down so
that the force of metering spring (2) is balanced with
the pressure at port P1. The relationship in the po­sition of spool (1) and body (10) (fine control hole f is
at a point midway between drain hole D and pump
pressure chamber PP) does not change even if the
pressure at port P1 becomaes max.
Therefore, metering spring (2) is compressed pro­portionally to the amount of movement of the control
lever, so the pressure at port P1 also rises in pro­portion to the travel of the control lever. (Fig. 2)

Fig. 1

Fig. 2

1

P2P1

RKS00820

5

4

9
3
2

f

P

1

P

D

T

PP

10

2P1

RKS00830

10-72

SK714-5 SK815-5 SK815-5 turbo

STRUCTURE AND FUNCTION

3. During fine control (when the lever is returned)

(fine control → neutral)

When disc (5) starts to be returned, spool (1) is pu­shed up by the force of centering spring (3) and the
pressure at port P1.
When this happens, fine control hole f is connected
to drain chamber D and the pressure oil at port P1 is
released.
If the pressure at port P1 drops too far, spool (1) is
pushed down by metering spring (2), and fine con­trol hole f is shut off from drain chamber D.
At almost the same time, it is connected to pump
pressure chamber PP, and the pump pressure is
supplied until the pressure at port P1 recovers to a
pressure that corresponds to the lever position.
(Fig. 3).

L.H. PPC VALVE - PATTERN CHANGE (OPTIONAL)

5

4

9
3

2

f

P

1

P

Fig. 3

D

T

f

PP

2P1

RKS00840

SK714-5 SK815-5 SK815-5 turbo

10-73

STRUCTURE AND FUNCTION

CYLINDERS

BUCKET RAISE

1

CYLINDERS

23 4 5 6 7 9 8

BUCKET TILT

1. Bushing

2. Dust

3. Gasket

4. Gasket

5. Rod

6. Gasket

7. Ring

12

13

34

13

2

12

1

11 1 0

5

11 1 0

8. Bushing

9. Nut

10. Piston

11. Cilinder

12. Gasket

13. Head

6

7

9

7

RKS01100

8

RKS01110

Unit: mm

Cilinder Ø Rod Ø Piston Piston stroke
Bucket raise 35 55 678 1616 938 32

Bucket tilt 30 60 357 970 613 32

10-74

Max. cylinder

length

SK714-5 SK815-5 SK815-5 turbo

Min. cylinder

length

Key size