Thomas 85 Repair Manual
REPAIR MANUAL
Thomas 85 loader
Publication No. 53322/1
March, 2009
THOMAS EQUIPMENT LIABILITY WARRANTY
THE WARRANTY IS THE ONLY OBLIGATION OF THOMAS OR A THOMAS DEALER
TO THE PURCHASER OR ANYONE ELSE CONCERNING A PRODUCT, ITS SERVICE,
ITS USE OR PERFORMANCE OR ITS LOSS OF USE OR FAILURE TO PERFORM.
NEITHER THOMAS NOR A THOMAS DEALER HAVE MADE AND NEITHER WILL
MAKE ANY OTHER EXPRESSED OR IMPLIED REPRESENTATION, WARRANTY OR
AGREEMENT CONCERNING A PRODUCT. NEITHER THOMAS NOR A THOMAS
DEALER HAVE MADE OR WILL MAKE ANY REPRESENTATION, WARRANTY OR
AGREEMENT CONCERNING A PRODUCTS MERCHANTABILITY OR OTHER
QUALITY, ITS SUITABILITY FOR PURCHASER’S PURPOSE (EVEN IF A PURCHASER
HAS INFORMED THOMAS OR A THOMAS DEALER OF THAT PURPOSE), ITS
DURABILITY, PERFORMANCE OR OTHER CONDITION.
EVEN IF THOMAS OR A THOMAS DEALER WAS ADVISE OF THE POSSIBILITY OF
SUCH LOSS, NEITHER THOMAS NOR A THOMAS DEALER WILL BE LIABLE TO
PURCHASER OR ANYONE ELSE FOR ANY INDIRECT, INCIDENTAL
CONSEQUENTIAL, PUNITIVE, ECONOMIC, COMMERCIAL, OR SPECIAL LOSS
WHICH IS IN ANY WAY ASSOCIATED WITH A PRODUCT. THIS INCLUDES ANY LOSS
OF USE OR NON-PERFORMANCE OF A PRODUCT, ANY REPLACEMENT RENTAL OR
ACQUISITION COST, ANY LOSS OF REVENUE OR PROFITS, ANY FAILURE TO
REALIZE EXPECTED SAVINGS, ANY INTEREST COSTS, ANY IMPAIRMENT OF OTHER
GOODS, ANY INCONVENIENCE OR ANY LIABILITY OF PURCHASER TO ANY OTHER
PERSON.
PURCHASER MAY NOT ATTEMPT TO ENLARGE ITS RIGHTS UNDER THE
WARRANTY BY MAKING A CLAIM FOR INDEMNITY, FOR BREACH OF CONTRACT,
FOR BREACH OF COLLATERAL WARRANTY, FOR A TORT (INCLUDING
NEGLIGENCE, MISREPRESENTATION OR STRICT LIABILITY) OR BY CLAIMINGANY
OTHER CAUSE OF ACTION.
THE WARRANTY IS A CONDITION OF SALE OF THE PRODUCT TO PURCHASER
AND WILL THEREFORE APPLY EVEN IF PURCHASER ALLEGES THAT THERE IS A
TOTAL FAILURE OF THE PRODUCT.
N.B. Read and practice your Thomas operating and servicing instructions. Failure to do this may
void your warranty.
Publication Number 53322 rev. 1
2
FOREWORD
It is important when ordering replacement parts or making a service inquiry to provide both the model number
and serial number of your Thomas loader. The serial number plate is located at the rear of the machine on the
left hand side hydraulic oil tank. In the event that the serial number plate is missing, the serial number is
stamped on under the engine.
S/N Tag location.
Tag is found on
opposite side on
some models
C5000
S/N Stamp Location
3
SAFETY PRECAUTIONS
Practically all Service work involves the need to drive the
loader. The Owner’s / Operator’s Manual, supplied with
each loader, contains safety precautions relating to
driving, operating and servicing that loader. These
precautions are as applicable to the service technician as
they are to the operator and should be read, understood
and practiced by all personnel.
Prior to undertaking any maintenance or repair operations,
make the necessary safety precautions to prevent possible
personal injury to yourself, or to bystanders.
PERSONAL CONSIDERATIONS
* CLOTHING
The wrong clothing or carelessness in dress can
cause accidents. Check to see that you are
suitably clothed. Some jobs require special
protective equipment.
* SKIN PROTECTION
Avoid long term contact with used motor oil.
Follow work practices that minimize the amount
of skin exposed and length of time used oil stays
on your skin.
* EYE PROTECTION
Injury can be avoided by wearing eye protection
when engaged in chiseling, grinding, welding,
painting and any other task that involves airborne
matter.
* BREATHING PROTECTION
Fumes, dust and paint spray are unpleasant and
harmful. These can be avoided by wearing
respiratory protection.
* FOOT PROTECTION
Substantial or protective footwear with
reinforced toecaps will protect the feet from
falling objects. Additional oil-resistant soles
will help to avoid spilling.
* SPECIAL CLOTHING
For certain work it may be necessary to wear
flame or acid resistant clothing.
CAUTION
Avoid injury through incorrect handling of
components. Make sure you are capable of lifting
the object. If in doubt, get help.
EQUIPMENT CONSIDERATIONS
* MACHINE GUARDS
Before using any machine, check to ensure that
the machine guards are in position and
serviceable. These guards not only prevent parts
of the body or clothing coming in contact with
the moving parts of the machine but also ward
off objects that might fly off the machine and
cause injury.
* LIFTING APPLIANCES
Always ensure that lifting equipment, such as
chains, slings, lifting brackets, hooks and eyes
are thoroughly checked before use. If in doubt,
select stronger equipment. Never stand under a
suspended load or raised implement.
* HEARING PROTECTION
Loud noise may damage your hearing and the
longer the exposure the greater the risk of
hearing damage. Always wear hearing protection
when working around loud machinery.
* HAND PROTECTION
It is advisable to use a protective cream before
work to prevent irritation and skin
contamination. After work, clean your hands
with soap and water. Solvents such as white
spirits, paraffin, etc. may harm the skin.
* COMPRESSED AIR
The pressure from a compressed air line is often
as high as 100 psi (6.9 bar). Any misuse may
cause injury.
Never use compressed air to blow dust, filing
dirt, etc. away from your work area unless the
correct type of nozzle is fitted.
Compressed air is not a cleaning agent. It will
only move dust etc. from one place to another.
Look around before using an air hose as
bystanders may get grit into their eyes, ears and
skin.
4
* HAND TOOLS
Many cuts, abrasions and injuries are caused by
defective tools. Never use the wrong tool for the
job as this leads either to injury or to a poor job
done.
SAFETY PRECAUTIONS
* HOUSEKEEPING
Many injuries result from tripping or slipping
over, or on, objects or materials left lying around
by a careless worker.
Never Use:
A hammer with a loose or split handle.
Spanners or wrenches with spread or worn
jaws.
Wrenches or files as hammers, drills, clevis
pins or bolts as punches.
For removing or replacing hardened pins use a
copper or brass drift.
For dismantling, overhaul and assembly of major
and sub-components always use the Special
Service Tools recommended. These will reduce
the work effort, labor time and the repair cost.
Always keep tools clean and in good working
order.
* ELECTRICITY
Electricity has become so familiar in day to day
usage that it’s potentially dangerous properties
are often overlooked. Misuse of electrical
equipment can endanger life.
Before using any electrical equipment,
particularly portable appliances, make a visual
check to ensure that the cable is not worn or
frayed and that the plugs, sockets etc.are intact.
Make sure you know where the nearest isolating
switch for your equipment is located.
GENERAL CONSIDERATIONS
* SOLVENTS
Use only cleaning fluids and solvents that are
known to be safe. Certain types of fluids can
cause damage to components such as seals, etc.
and can cause skin irritation. Solvents should be
checked that they are suitable not only for the
cleaning of components and individual parts but
also that they do not affect the personal safety of
the user.
Prevent these accidents from occurring. If you
notice a hazard, don’t ignore it, remove it.
A clean hazard free place of work improves the
surroundings and daily environment for
everybody.
* FIRE
- Extinguish matches, cigars, cigarettes etc.
before throwing them away.
- Work cleanly, disposing of waste material into
proper containers.
- Locate all the fire extinguishers and ensure all
personnel know how to operate them.
- Do not panic, warn those near and sound the
alarm.
- Do not allow or use an open flame near the
loader fuel tank, battery or component parts.
* FIRST AID
In the type of work that machanics are engaged
in, things such as dirt, grease, fine dust etc. all
settle upon the skin and clothing. If a cut,
abrasion or burn is disgrarded it may be found
that a septic condition has formed in a short time.
What appears at first to be trivial could become
painful and injurious. It only takes a few minutes
to have a fresh cut dressed but it will take longer
if you neglect it.
* CLEANLINESS
Cleanliness of the loader hydraulic system is
essential for optimum performance. When
carrying out service and repairs, plug all hose
ends and components connections to prevent dirt
entry.
Clean the exterior of all components before
carrying out any form of repair. Dirt and abrasive
dust can reduce the efficiency and working life
of a component and lead to costly replacement.
Use of a high pressure washer or steam cleaner is
recommended.
5
SAFETY PRECAUTIONS
OPERATIONAL CONSIDERATIONS
* Stop the engine, if at all possible, before
performing any service.
* Place a warning sign on loaders which, due to
service or overhaul, would be dangerous to start.
Disconnect the battery leads if leaving such a
unit unattended.
* Do not attempt to start the engine while standing
beside the loader or attempt to bypass the safety
starting system.
* Avoid prolonged running of the engine in a
closed building or in an area with inadequate
ventilation as exhaust fumes are highly toxic.
* Always turn the radiator cap to the first stop to
allow pressure in the system to dissipate when
the coolant is hot.
* Never work beneath a loader which is on soft
ground. Always take the unit to an area which
has a hard working surface, preferably concrete.
* If it is found necessary to raise the loader for
ease of maintenance, make sure that safe and
stable supports (such as jackstands that have a
rated capacity greater than the loader weight)
are installed beneath the main frame before
commencing work.
* Use footsteps or working platforms when
servicing those areas of the loader that are not
within easy reach.
* Before loosening any hoses or tubes, switch off
the engine, remove all pressure in the lines by
operating the foot pedals several times. This will
remove the danger of personal injury by oil
pressure.
* Prior to pressure testing, make sure all the hoses
and connectors on both the loader and on the test
machine are in good condition and tightly sealed.
Pressure readings must be taken with the gauges
specified. The correct procedure should be
rigidly observed to prevent damage to the system
or the equipment and to eliminate the possibility
of personal injury.
* Always lower equipment to the ground when
leaving the loader.
* To avoid personal injury, service the loader with
the arms down and the bucket or attachment on
the ground. If it is necessary to service the
loader with the boom arms raised, be sure to
engage the boom supports. Never work under or
around a loader with raised boom arms without
boom support engaged.
* If high lift attachments are installed on a loader,
beware of overhead power and telephone lines
when travelling. Drop attachment near to ground
level to increase stability and minimize risks.
* Do not park or attempt to service a loader on an
incline. If unavoidable, take extra care and block
the wheels.
* Escaping hydraulic / diesel fluid under pressure
can penetrate the skin causing serious injury. Do
not use your hand to check for leaks. Use a piece
of cardboard or paper to search for leaks. Stop
the engine and relieve pressure before connecting
or disconnecting lines. Tighten all connections
before starting the engine or pressurizing the
lines. If any fluid is injected into the skin, obtain
medical attention immediately.
* Prior to removing wheels and tires from a loader,
check to determine whether additional ballast
(liquid or weight) has been added. Seek
assistance and use suitable equipment to support
the weight of the wheel assembly.
* When inflating tires beware of over inflation;
constantly check the pressure. Over inflation can
cause tires to burst and result in personal injury.
* Safety precautions are very seldom the figment
of someones imagination. They are the result of
sad experience where most likely someone has
paid dearly through personal injury.
* Heed these precautions and you will protect
yourself accordingly. Disregard them and you
will duplicate the sad experiences of others.
6
SAFETY PRECAUTIONS
SERVICE TECHNIQUES
A. SERVICE SAFETY
Appropriate service methods and proper repair
procedures are essential for the safe, reliable
operation of all motor vehicles as well as the
personal safety of the individual doing the work. This
shop manual provides general directions for
accomplishing service and repair work with
tested effective techniques. Following them will help
assure reliability.There are numerous variations in
procedures, techniques, tools and parts for servicing
vehicles as well as in the skill of the individual doing the
work. This manual cannot possibly anticipate all such
variations and provide advice or cautions as to each.
Accordingly, anyone who departs from the instructions
provided in this manual must first establish that he or she
compromises neither his personal safety nor the vehicle
integrity by his choice of methods, tools or parts.
B. SERVICE TECHNIQUES
Clean the exterior of all components before carrying out
any form of repair. Dirt and abrasive dust can reduce the
efficient working life of a component and lead to costly
replacement.
Use cleaning fluids which are known to be safe. Certain
types of fluid can cause damage to O- rings and cause
skin irritation. Solvents should be checked that they are
suitable for the cleaning of components and also that they
do not risk the personal safety of the user.
Time spent on the preparation and cleanliness of working
surfaces will pay dividends in making the job easier and
safer and will result in overhauled components being
more reliable and efficient in operation.
When installing a new hose, loosely connect each end and
make sure the hose takes up the designed position before
tightening the connection. Clamps should be tightened
sufficiently to hold the hose without crushing and to
prevent chafing.
The hoses are the arteries of the unit. Be sure they are in
good condition when carrying out repairs or maintenance.
Otherwise the machines output and productivity may be
affected.
After hose replacement to a moving component, check
that the hose does not foul by moving the component
through the complete range of travel.
Hose connections which are damaged, dented , crushed or
leaking, restrict oil flow and the productivity of the
components being served. Connectors which show signs
of movement from the original swaged position have
failed and will ultimately separate completely.
A hose with a chafed outer cover will allow water entry.
Concealed corrosion of the wire reinforcement will
subsequently occur along the hose length with resultant
hose failure.
Ballooning of the hose indicates an internal leakage due
to structural failure. This condition rapidly deteriorates
and total hose failure soon occurs.
Kinked, crushed, stretched or deformed hoses generally
suffer internal structural damage which results in oil
restriction, a reduction in the speed of operation and
ultimate hose failure.
Free moving, unsupported hoses must never be allowed to
touch each other or related working surfaces. This causes
chafing which reduces hose life.
Replace O rings, seals or gaskets whenever they are
disturbed. Never mix new and old seals and O rings,
regardless of condition. Always lubricate new seals and O
rings with hydraulic oil before installation.
When replacing component parts use the correct tool for
the job.
C. HOSES AND TUBES
Always replace hoses and tubes if the end connections are
damaged. Be sure any hose installed is not kinked or
twisted.
D. PRESSURE TESTING
Prior to pressure testing, be sure all hoses are in good
condition and all connections tight. Pressure readings
must be taken with gauges of specified pressure readings.
The correct procedure should be rigidly observed to
prevent damage to the system or the equipment and to
eliminate the possibility of personal injury.
7
SAFETY PRECAUTIONS
E. BEARINGS
Bearings which are considered suitable for further service
should be cleaned in a suitable solvent and immersed in
clean lubricating oil until required.
Installation of a bearing can be classified into two (2)
ways:
press fit on rotating parts such as shafts and gears,
push fit into static locations such as reduction gear
houses.
Where possible, always install the bearing onto the
rotating components first. Use the correct tools or a press
to install a bearing or bushing. In the absence of the
correct tools or press, heat the bearing and / or casing in
hot oil to assist the installation of the bearing.
When bearings or bushings are removed, always carefully
check that the bearing is free from discoloration and signs
of overheating. Also check for mechanical damage such
as excessive clearance, nicks and scuffing. If in doubt,
replace the bearings or bushings.
Bearings should never be removed unless absolutely
necessary. Always use the recommended puller to reduce
the risk of bearing or related component failure.
These bearings and bushings are subjected, in normal
operation, to high working loads and adverse conditions.
Be sure during normal routine servicing, maintenance or
repair that bearings are given the right attention and are
installed with care.
F. BOOM SUPPORTS
For safety while performing regular service or
maintenance work, the loader is equipped with boom
supports.
The boom supports, when extended, prevent the boom
arms from dropping if hydraulic pressure is relieved or
the foot control pedals are accidentally cycled.
To operate the boom supports, first remove any bucket or
attachment from the quick - tach; raise the boom arms to
full height and shut off the engine. Raise the boom
handles up and push out toward the boom arms to extend
the boom supports. (fig. C320, C321)
WARNING
To avoid personal injury, service the loader with the
arms down and the bucket or attachment on the
ground. If it is necessary to service the loader with
the boom arms raised be sure to engage the boom
supports. Never work under or around a loader with
raised boom arms without boom supports engaged.
8
TABLE OF CONTENTS
Section 1 Hydraulic System
Hydraulic Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.1
Gear Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.2
Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.3
Hydraulic Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.4
Hydraulic Oil Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.5
Hydraulic Oil Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.6
Trouble Shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.7
Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.8
Conversion Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.9
Section 2 Hydrostatic Drive System
Hydrostatic Drive Circuit ..................................................................2.1
Specifications.....................................................................................2.2
General Information...........................................................................2.3
Trouble Shooting ...............................................................................2.4
Pressure Tests.....................................................................................2.5
Towing Procedure ..............................................................................2.6
Flushing The Hydraulic System ........................................................2.7
Start - up Procedure ...........................................................................2.8
Gear Pump Replacement ...................................................................2.9
Tandem Pump Replacement ..............................................................2.10
Tandem Pump Parts Diagram ............................................................2.11
Drive Motor .......................................................................................2.12
Torque Specs ......................................................................................2.13
Section 3 Final Drive
Specifications and Maintenance ........................................................3.1
Lubrication.........................................................................................3.2
Drive Chain........................................................................................3.3
Drive Motor Sprocket ........................................................................3.4
Axle Assembly...................................................................................3.5
Parking Brake ....................................................................................3.6
Trouble Shooting ...............................................................................3.7
Section 4 Controls
Steering ..............................................................................................4.1
Foot Pedals.........................................................................................4.2
Hand Controls ....................................................................................4.3
Throttle...............................................................................................4.4
Restraint Bar ......................................................................................4.5
Parking Brake ....................................................................................4.6
Trouble Shooting ...............................................................................4.7
9
TABLE OF CONTENTS
Section 5 Electrical
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.1
Wiring Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.2
Instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.3
Ignition Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.4
Engine Glow Plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.5
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.6
Electrical Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.7
Starter Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.8
Charging Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.9
Safety Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.10
Auxiliary Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.11
Accessory Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.12
Trouble Shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.13
Section 6 Main Frame
Quick - Tach.......................................................................................6.1
Boom Arms........................................................................................6.2
Boom Support....................................................................................6.3
ROPS .................................................................................................6.4
Rear Door...........................................................................................6.5
Section 7 Engine
Maintenance.......................................................................................7.1
Cylinder Head ....................................................................................7.2
Replacement.......................................................................................7.3
Specifications.....................................................................................7.4
Trouble Shooting ...............................................................................7.5
Section 8 Maintenance & Specifications
Maintenance.......................................................................................8.1
Trouble Shooting ...............................................................................8.2
Special Tools ......................................................................................8.3
Specifications.....................................................................................8.4
Conversion Charts..............................................................................8.5
10
SECTION 1 HYDRAULIC SYSTEM
Hydraulic Circuit 1.1
Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pg.1-2
Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-3
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-4
Maintenance Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-4
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pg. 1-5
Gear Pump 1.2
Replacing the Gear Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-6
Gear Pump Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-7 ~ 8
Start Up Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-9
Control Valve 1.3
Testing / Adjusting the Relief Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-10 ~ 11
Control Valve Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-11 ~ 12
Exploded Illustration Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-13 ~ 14
Control Valve Disassembly / Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-15 ~ 24
Exploded Illustration Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pg. 1- 25 ~ 28
Control Valve Disassembly/Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pg. 1-29 ~ 32
Hydraulic Cylinders 1.4
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pg. 1-33
Testing Piston Seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-34
Lift Cylinder Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-35
Tilt Cylinder Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-36
Cylinder Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-37 ~ 38
Cylinder Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-39
Cylinder Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-39 ~ 40
Hydraulic Oil Filter 1.5
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-41
Filter Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-41
Hydraulic Oil Reservoir 1.6
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-42
Checking the Oil Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-42
Adding Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-42
Servicing the Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-43
Trouble Shooting 1.7
Trouble Shooting Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-44 ~ 45
Torque Chart 1.8
Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-45
Conversion Charts 1.9
Conversion Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-46
1-1
1
HYDRAULIC CIRCUIT 1.1
C5274
NOTE: Foot pedal control operated machine illustrated.
Hydraulic fluid comes out the port closest to the spool
end of the valve when the spool is pushed in.
Hydraulic fluid received at the fixed end of the cylinder
pushes it out. When the hydraulic cylinder receives fluid
at the ram (rod) end, it retracts.
1-2
HYDRAULIC SCHEMATIC 1.1
1
C5204
1-3
SPECIFICATIONS & MAINTENANCE 1.1
Hydraulic Specifications
1
Pump Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Gear
Pump Capacity (theoretical) . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3GPM(23.9l/m)
Rated speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3140
Control Valve . . . . . . . . . . . . . . . . . . . . . . . .Series type with float on boom and
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .detent on auxiliary
Main Relief Pressure, +/- 50PSI (3.5 Bar) . . . . . . . . . . . . . . . . . . . . . . .2200 psi
Reservoir Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10Gal.(38 L)
Fluid Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10W30 API CF
Filtration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 micron
Lift Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 per loader
Lift Cylinder Bore Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 in. (5 cm.)
Lift Cylinder Rod Diameter . . . . . . . . . . . . . . . . . . . . . . . . . .1.125 in. (2.86cm.)
Tilt Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 per loader
Tilt Cylinder Bore Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 in. (5 cm.)
Tilt Cylinder Rods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.125 in. (2.86 cm.)
Lift Cycle +/- 1.5 seconds (Up / Down) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6/4
Tilt Cycle + / - 1.5 seconds (Up / Down) . . . . . . . . . . . . . . . . . . . . . . . . . . .2.5/3
Maintenance Schedule . . . . . . . . . First (HRS) . . . . Every (HRS)
Oil level check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 . . . . . . . . . . . . . . . . . . . . . .8
Oil filter change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 . . . . . . . . . . . . . . . . . . . .150
General system check ( leaks etc. ) . . . . . . . . . . . . . . . .8 . . . . . . . . . . . . . . . . . . . . . .8
Lubricate (grease pivots) . . . . . . . . . . . . . . . . . . . . . . . .8 . . . . . . . . . . . . . . . . . . . . . .8
Hydraulic oil change . . . . . . . . . . . . . . . . . . . . . . . . . 1000 . . . . . . . . . . . . . . . . . . 1000
1-4
GENERAL INFORMATION 1.1
Hydraulic System
Oil is drawn from the hydraulic oil reservoir through a
100 micron element. From there it travels to the main
hydraulic pump. (fig. C5003).
•The hydraulic pump is a gear type which is driven by a
shaft and coupler through the hydrostatic drive pump at
engine speed. The oil then flows from the gear pump to
the hydraulic control valve. (C5248).
•The hydraulic control valve is equipped with an
adjustable relief valve which is adjusted to 2200 psi (148
bar). The control valve is a series type with 3 spools
(banks). The various spools activate the boom, bucket and
auxiliary hydraulic functions.
When the spools are in neutral, oil flows from the
hydraulic gear pump, through the control valve and
returns to the 10 micron hydraulic filter. From the
hydraulic filter, the fluid flows to charge the tandem
hydrostatic pump and pressurize the hydraulic brake
release system and then back to the hydraulic reservoir.
Each control valve section spool end contains a centering
spring which returns the spool to neutral when the foot
pedal, or control handle, is released. (fig.C5195).
Gear pump Location
1
C5003
Control valve location
C5248
•The boom section, on foot control operated loaders, has
a detent mechanism to hold the spool in the float position.
The auxiliary section is operated by foot pedal operation,
or may have an optional electrical solenoid operated
control, and may be engaged momentarily by the control
lever mounted switch, forward or reverse, or by engaging
the dash mounted toggle switch for constant power in the
forward direction only.
The system relief valve operates when ever a hydraulic
function has been restricted or overloaded (fig. C5063).
To protect against excessive pressure build up, the relief
valve opens and allows oil to return to the valve outlet.
The system relief valve is adjustable, and is preset at
2200 psi (148 bar).
•Load check valves are located between the ports of each
spool circuit. The function of the load check valve is to
hold the boom arms or bucket in position during initial
spool movement.
Spring return
C5195
Relief valve
C5063
1-5
1
GEAR PUMP 1.2
Replacement
Start the gear pump removal procedure by removing any
attachment, raising the boom arms and engaging the
boom support pins. Shut off the engine.
WARNING
To prevent personal injury do not work under the
boom arms without the boom supports engaged.
Remove bolts
1 Remove the seat. (fig. C5017)
2 Attach a vacuum system to the hydraulic oil reservoir
filler location. Or drain the oil reservoir. Seal the threads
on the drain plug, if removed, with teflon tape or a liquid
form of pipe sealant before re - installing.
3 Disconnect the hydraulic hoses from the gear pump.
( fig. C5114 ) Remove the pump fittings. Cap all open
hoses to prevent contamination. After capping ends you
may unhook vacuum system from oil reservoir.
4 Remove the bolts holding the gear pump to the
hydrostatic tandem section. ( fig. C5003) Remove the
gear pump.
5 Replace gear pump in reverse order.
IMPORTANT
If gear pump replacement is being done because of
failure, the hydraulic system and oil should be
checked for contamination.
6 If the hydraulic system has been contaminated by
pump or other failure you must follow the cleaning
procedure outlined in section 2.7.
WARNING
Use caution when dealing with hydraulic fluid under
pressure. Escaping fluid under pressure can
penetrate the skin and cause serious injury.
C5017
Hyd. Hoses
C5003
Screws
Hyd. lines
C5003
7 Start the engine and check for leaks. Do not use your
hands to find leaks.
8 Check the fluid level in the hydraulic oil reservoir
and replenish as required. (fig. C5006)
IMPORTANT
When making repairs to the hydraulic system, keep
the work area and parts clean. Use caps and plugs
on all open lines and ports.
Oil level
C5006
1-6
GEAR PUMP 1.2
Disassembly
1. General
The following is a detailed procedure for disassembly
and assembly of the D series hydraulic gear pump. Prior
to proceeding it may be necessary to prepare some subassemblies separately. The details for preparing each
subassembly are given in the following section, as well as
some general recommendations.
2. Cleanliness
Cleanliness is the primary factor for reliable pump
performance. Wash the outside of the pump thoroughly
before disassembly and all pieces prior to assembly.
Cleaning parts with clean shop solvent and air drying is
usually adequate.
3. Lubrication Of Moving Parts
During assembly, it is imperative to provide
lubrication with clean hydraulic oil to all the running
parts of the pump. It is also necessary to coat the seals
with grease. The absence of lubrication during assembly
can cause the unit to seize after a few minutes of running.
Screws
1
Hyd. lines
C5003
4. Care Of Surface Treatment
Be careful when handling all the internal surfaces,
especially bearings, gears, and body faces. Do not touch
or score them with metal tools or cutting edges.
5. Marking The Parts
Mark the parts before completely disassembling a
pump. The marks allow components to be reassembled in
the same relative position. This action should be applied
to the body, bearings, and gears. Scribing, bluing, or
using a felt pen to mark the outside of the body on the
inlet side is suggested to indicate the relative position of
the front flange and the rear cover to the body. Mark the
bearing blocks also on the inlet side and the gears
position relative to each other. DO NOT scribe internal
surfaces.
IMPORTANT
Mark all pieces during disassembly so that the unit
can be reassembled correctly. Installing components
incorrectly could severely damage the unit and/or
cause it to not function properly.
1-7
1
GEAR PUMP 1.2
Disassembly 85
1
2
2
3
2
1. Gear Pump Assembly
2. Seal Kit
3. O-ring
1-8
GEAR PUMP 1.2
Start up Procedure
1 Mount the gear pump to the loader. (fig. C5003)
2 Connect the hydraulic lines.
3 Start the engine and idle for 3 minutes @ zero
pressure, (auxiliary not engaged). Engage auxiliary.
a. Half speed at zero restriction.
b. Half speed, intermittently loaded to 500 psi (35 bar)
c. Full speed, intermittently loaded to 1000 psi (69 bar)
4 Check for leaks.
5 Check flow and pressure at rated speed as outlined in
section 1.3.
C5003
Screws
Hyd. lines
1
WARNING
Use caution when dealing with hydraulic fluid under
pressure. Escaping fluid under pressure can
penetrate the skin and cause serious injury.
IMPORTANT
When making repairs to the hydraulic system, keep
the work area and parts clean. Use caps and plugs
on all open lines and ports.
Intermittently load the gear pump at start up
Flow test meter p / n 960456
C2352
1-9
1
CONTROL VALVE 1.3
Testing and Adjusting the Relief Valve Pressure
Hoses and gauges required for this test must be capable
of withstanding 3000 psi (207 bar) continuous pressure,
and hydraulic flow meter capable of measuring 30 gallons
per minute. (113 l/min) (fig. C5004) This test also
checks the status of the gear pump capacities.
Pressure fluctuations may be caused by restricted oil flow
through the relief valve. The relief valve may need
replacing when its filter is contaminated.
1 Install the flow meter / pressure tester to the auxiliary
hydraulic quick couplers. The female coupler attached to
the loader provides the power out when the auxiliary
control is engaged. (fig, C5004) Connect the flow meter
and pressure gauge inlet side to match the power out of
the female auxiliary coupler to prevent meter and gauge
damage. Be sure to connect a return line to the male
auxiliary hydraulic quick coupler. (fig. C2352)
2 Start the engine and engage the auxiliary hydraulic
system. Increase the engine speed to full operating rpm.
(See Section 7 for checking and adjusting engine speed to
3000 rpm plus or minus 25 rpm)
C5004
Auxiliary couplers
Pressure out
CAUTION
Adjusting the relief valve setting too high may cause
damage to the gear pump.
3 Turn the flow control valve on the flow meter to
restrict the oil flow down to 2 gal /min. (7.5 l/min ) As
you are turning the flow control valve, watch the pressure
gauge and make sure it does not go over 3000 psi (207
bar). Stop further adjustment immediately if the reading
goes over this setting. Shut off the auxiliary hydraulic
system and shut off the engine. Move to step 6 to make
initial setting.
WARNING
To prevent personal injury or damage to the loader,
do not adjust the relief valve while the engine is
operating.
C2352
Relief valve
C5063
1-10
CONTROL VALVE 1.3
4 Repeat steps 2 and 3 if necessary. Allow the loader to
operate at this setting until the oil temperature has
increased to 160° F (71ºC), operating temperature.
5 Turn the flow control valve further to restrict the oil
flow to no flow. (Zero) Correct pressure setting is 2100
psi +/- 100 psi (148 bar +/- 6.9 bar).
6 If adjustment is necessary, return the flow control
valve to the open position, shut down the auxiliary
hydraulic system and shut off the engine. Locate the
control valve in the engine compartment.
7 Loosen the jam nut on the relief valve adjusting
screw and turn the screw clockwise, counting the turns,
until the screw bottoms out. (fig. C5063)
8 Turn the screw back. Reduce the number of turns
that you turned in to increase the pressure, increase the
number of turns to decrease the pressure.
9 Retake the pressure readings by performing steps 2
through 5. If necessary make further adjustments by
repeating steps 6 through 9.
NOTE: If adequate pressure and / or flow is not
available, the gear pump could be failing, the intake to
the gear pump is restricted, or the filter in the relief
valve is clogged.
Control Valve Replacement
1 Remove any attachment and shut off the engine.
Turn the key on with the safety devices activated so the
pedals can be moved. Slowly jog both pedals and press
the electric auxiliary switch. This will take any pressure
out of the system.
1
Jam nut
Relief valve
C5063
Solenoid coil
mounting nuts
C5064
Disconnect control cables
IMPORTANT
Clean the work area prior to repair. Cap all open
lines, fittings and ports to prevent contamination.
2 Disconnect the control cables, electrical solenoid
spool locks, and electrical auxiliary solenoid wiring
connectors if equipped. (fig. C5064, C5065)
3 Disconnect the the inlet hose coming from the gear
pump. Cap the hose and fitting and remove the adapter
fitting in the control valve.
4 Disconnect the 6 hoses going to the boom, bucket
and auxiliary circuits. Marking the hoses as you remove
them is recommended to ease re-assembly and assure the
circuits are functioning properly at restart.(fig. C5005)
5 Disconnect the accumulator line from the electric
auxiliary circuit and remove the adapter fitting( if so
equipped). Plug and cap all open ports and hose ends.
C5065
Control valve mounts
C5005
1-11
1
CONTROL VALVE 1.3
6 Disconnect the return line from the control valve and
remove the adapter fitting. Plug and cap all open ports
and hose ends.
7 Remove the 3 nuts holding the control valve to the
mount and remove the control valve.
8 Remove any fittings left in the control valve. Cap all
open ports to prevent contamination. Place these fittings
in the new or repaired control valve. Be sure to check all
fitting flares and o -rings for damage and replace as
required.
Install valve to mount
IMPORTANT
Follow the hydraulic fitting torque chart in Section
1.10 when connecting fittings and lines.
9 Assemble the control valve to the loader in the
reverse order above. Torque the bolts holding the control
valve to the mount at 15 ft lbs. (20.4 Nm)
10 After all connections have been made, including the
control valve electrical connections, check the oil level in
the hydraulic reservoir and top off if necessary.
WARNING
Use extreme caution when checking the hydraulic
system for leaks. Fluid under pressure can penetrate
the skin and cause serious injury.
11 Start the engine and cycle the various hydraulic
functions to check for leaks. Make sure the control valve
lock system is functioning properly. Do not use your
hands to check for leak locations, fluid under operating
pressure can penetrate the skin and cause serious personal
injury.
C5066
Control valve fittings
C5066a
Check fluid level
WARNING
All safety switches must be connected and
functioning to prevent possible operator injury.
12 After checking for leaks, you must retest the relief
valve setting as outlined on page 1-6 Testing and
adjusting.
C5006
Replenish fluid as required
C5007
1-12
CONTROL VALVE 1.3
Control Valve Disassembly 85
Control valve, No Auxiliary (Up to S/N LB002671, excluding LB002578
1
10
1
12
C3287
13
14
15
7
5
11
9
8
3
2
4
6
1-13
1
CONTROL VALVE 1.3
Control Valve Disassembly 85
Diagram Legend
1. Seal kit
2. Control, spring return
3. Detent, spring return kit
4. Section, inlet
5. Section, outlet
6. Bolt
7. Mount
8. Relief valve
9. Spool, tilt
10. Spool, lift
11. Solenoid, coil
12. Solenoid and lock kit
13. Connector
14. Seal kit, spring return side
15. Seal kit, section
1-14
CONTROL VALVE 1.3
Disassembly / Repair 85
Remove the hydraulic control valve as outlined in the
removal section, page 1-7. Ensure all openings are
plugged to prevent solvents and dirt from contaminating
the control valve assembly. Before disassembling the
hydraulic control valve, clean the body with a suitable
solvent and dry with compressed air.
WARNING
To avoid eye injury, use safety goggles when
cleaning with compressed air.
Refer to diagram C3287, pg. 1-13 to assist in the
disassembly of the control valve.
1. Remove the solenoid coils and O-ring seals. (fig.
C2368).
2. Remove the locking pin assembly from adapter
block. (fig. C2369)
3. Remove the pressure relief valve. (fig. C2370) Tip
the valve down slightly to ensure the valve poppet comes
out with the spring
Note: Figure C5179 shows an exploded view of the
relief valve system.
O-ring seals
1
C2368
Locking pin assembly
C2369
Relief valve assembly
C2370
Poppet
Valve poppet
Cap
Spring
Sealing washer
C5179
1-15
CONTROL VALVE 1.3
1
Disassembly / Repair 85
(cont’d)
4. Remove the screws retaining the lock adapters to the
control valve assembly. (fig. C2372).
5. Remove the plate and adapter from the control valve
and spool. fig. C2373, C2374)
Remove screws
C2372
Scraper seal plate
6. Remove the O-ring seals and seal shim. (C2374).
Discard the seals and replace with new.
7. Clean the lock adapter with solvent and inspect the
inside of the lock adapter for excessive wear such as
gouging or chipping. Replace with new if worn.
8. Lubricate a new spool O-ring with system oil and
install to the lock adapter. (fig. C2375)
C2373
C2374
Spool O-ring
Section O-ring
O-ring shim
Spool O-ring
C2375
1-16
CONTROL VALVE 1.3
Disassembly Repair 85 (cont’d)
9. Lubricate the spool O-ring shim with system oil and
install over spool seal. (fig. C2376).
10. Lubricate the section O-ring seal with system oil and
install to the lock adapter assembly. (fig. C2377).
C2376
C2377
Section O-ring seal
Spool O-ring shim
1
11. Figure C2378 shows the completely resealed lock
adapter assembly ready to be installed to the control valve
assembly.
12. Remove the screws retaining the spring return caps to
the control valve assembly. (fig. C2379). Remove the
spring return assemblies.
Lock adapter assembly
C2378
Remove screws
C2379
1-17
CONTROL VALVE 1.3
1
Disassembly / Repair 85
(cont’d)
13. Note: The plastic cap over the tilt spring has flat
washers to distribute the load of the mounting screws to
prevent cap damage. (fig. C2380). Be sure to install the
flat washers when reassembling to the control valve.
14. Figure C2381 shows spring assemblies and detent
mechanisms as viewed with the caps removed.
Tilt spring return cap
Mounting screws
Flat washers
C2380
Return springs
15. Remove the section spools noting their location to
the appropriate bores. (fig. C2382). Do not replace the
spools in any other spool bores than the one it came out
of. Clean the spools and valve sections with solvent and
inspect for gouging or chipping. Replace sections as
required. Minor scratches on the spool may be removed
with fine emery cloth. Be sure to remove all solvent from
the control valve body if no further disassembling of the
control valve is to be preformed.
16. Install new O-ring seals at time of assembly. (fig.
C2383) Lubricate the seal, bore and spool with system oil
when reassembling the components.
C2381
Remove spools
C2382
Spool O-ring
C2383
1-18
CONTROL VALVE 1.3
Disassembly / Repair 85
(cont’d)
17. Install the O-ring spacer shim to the spool O-ring
seal. (fig. C2384).
18. Install the flat washer over the O-ring spacer. (fig.
C2385) The spring return side of the control valve is now
complete.
1
C2384
C2385
19. The auxiliary section, section without lock adapter,
has an O-ring seal located in a machined groove in the
section housing. (fig. C2386) Remove the seal using a
pick tool and replace with new. Lubricate the O-ring with
system oil. Figure C2387 shows the seal installed.
C2386
C2387
1-19
CONTROL VALVE 1.3
1
Disassembly / Repair 85
(cont’d)
20. Section seals may be replaced without removing
spools and spring return mechanisms. Loosen the bolts
retaining the control valve sections together. (fig. C2388).
Upon assembly follow the torque specifications given
Section 8.
21. Note the flat spacer washers used on the upper bolts.
(fig. C2389)
Loosen section bolts
C2388
Flat spacer washer
C2389
22. Remove the bolts and mounting brackets. (fig.
C2390)
23. Separate the control valve sections. (fig. C2391)
Mounting bracket
C2390
Separate sections
C2391
1-20
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