MANITOU MLT634 Service Manual

MAINTENANCE INSTRUCTIONS

ELECTROHYDRAULIC ACTUATION
MODULE

TYPE EMS

MAINTENANCE

Type : electrohydraulic actuation module EMST = EMSP

SUMMARY

1. Introduction

1.1 Foreword

1.2 Safety instructions

2. Troubleshooting

3. Fondamental rules

3.1 General information concerning electrohy­draulic actuation module connection

4. Removal / installation of electrohydraulic
actuation module

4.1 General recommendations

4.2 Removal of a single electrohydraulic actua­tion module

4.3 Removal of one of several electrohydraulic
actuation modules assembled together

4.4 Electrohydraulic actuation module assem­bly

4.5 Removal / disassembly of the electrohy­draulic transformation stage

5. Removal / assembly of connecting flange and
filter

5.1 Connecting flange removal / assembly

5.2 Filter replacement

6. Neutral position adjustement

1. INTRODUCTION

1.1 - Foreword

It is recommended that only qualified personnel perform
the installation, connection and maintenance of this devi­ce, and that all operations be carried out in compliance
with the technical standards in force and the cleanliness
regulations specific to this type of installation.

To ensure maximum performance and safety during

maintenance operations we advise you to

READ THIS MANUAL THOROUGHLY

All informations, illustrations, instructions and characte­ristics contained in this document are based on the
latest product information available at the time of publi­cation. In its attempts to maintain a high-quality product,
MANITOU reserves the right to make design or technical
modifications at any time and without prior notification.

1.2 - Safety instructions

Please pay a particular attention to the signals of the
safety alertsand special instructions in this manual. They
are indicated in the following manner :

Indicates informations or instructions which
must be followed to guarantee your safety
during operations.

CAUTION : WARNING AGAINST POSSIBLE

EQUIPMENT DAMAGE.

7. Start-up procedures

NOTE : Useful information.

14

MAINTENANCE INSTRUCTIONS - Troubleshooting

Observed problems Probable cause

Absence of movement on all
the proportional functions.

Absence or defect of
movement on a proportional
function.

1. Supply voltage insufficient. Check minimum supply

2. Pilot pressure insufficient. Verify the supply pressure of

3. Sealing of the protection
filter of the proportional
controls.

1. Absence of signal of the
proportional control of the
distributor.

2. Signal defect of the propor­tional control of the distri­butor.

Additional verifications Solutions

voltage 9V of the proportional
control unit.

the pilot circuit of the
proportional control units
minimum 15 bar.

Clean the filter. Remove filter of the hydraulic

supply unit
(page 22).

Check the signal of the mani­pulator towards the proportio­nal control units.

Value = 2.5 volts if manipula­tor knob is at neutral.

Ensure that the signal voltage
comprises of between 1 and
4 volts while using the control
knob of the manipulator.

Verify the connections and
clusters between proportional
control unit and manipulator.

If OK, change the manipula­tor.

If value outside of limits,
change the manipulator.

Untimely movement with pro­portional control of the mani­pulator in neutral.

Sudden or irregular move­ment on all the proportional
functions.

Sudden or irregular move­ment on a single proportional
function.

Sudden or irregular move­ment in a single direction on
a proportional function.

3. Insufficient voltage of the
proportional control units of
the distributor.

Signal defect of the proportio­nal controls of the manipula­tor.

Protection filter partially sea­led.

Looking or jamming of the
position sensor of the propor­tional control unit.

Looking or jamming of the
pilot drawer of the proportio­nal control unit.

Verify control voltage 5 volts
provided by the proportional
control units to the manipula­tor.

Check the signal of the mani­pulator towards the proportio­nal control units.

Value = 2.5 volts if manipula­tor knob is at neutral.

Clean the filter. Remove filters of hydraulic

If voltage nil or insufficient,
replace the proportional
control unit
(pages 17, 18, 19).

Verify the connections and
clusters between proportional
control unit and manipulator.

If OK, change the manipula­tor.

supply unit
(page 22).

Replace the proportional
control unit (pages 17, 18,

19).

Replace the proportional
control unit (pages 17, 18,

19).

15

MAINTENANCE INSTRUCTIONS - Troubleshooting

Observed problems Probable cause

Symmetry defect of the
control of a proportional func­tion.

Oil leak between two propor­tional control units.

Oil leak between electro­hydraulic and mechanical
interface of the proportional
control units.

Shift of the neutral position of
the position sensor.

Imperviousness defect of the
piping of the pilot circuit bet­ween the units.

1. Packing damaged.

2. Pilot pressure too high. Verify that the supply pressu-

Additional verifications Solutions

Adjust the neutral position of
the position sensor
(page 24).

Change the packing
(pages 17, 18, 19).

Change the packing
(page 20).

re of the pilot circuit does not
exceed 35 bar.

3. FONDAMENTAL RULES

3.1 - General information concerning electrohydraulic actuation module connection

Hydraulic

When removing the electrohydraulic actuation module, all openings must be plugged immediately to prevent any conta­mination of the hydrailic system.
Check the hydraulic installation’s oil quality and filtration capacity during all servicing / maintenance operations.
When replacing the electrohydraulic actuation module, remove the plastic plugs from the openings and lines just before
making the connections.
Do not tighten connectors to a torque greater than that specified in the assembly instructions.
The use of Teflon tape, hemp and joint filler is prohibited.
Hydraulic lines and connections must not be under any strain whatsoever.

Electric

All along the operations, pay attention not to damage the cables and electrical connections.
Check that there is no residual voltage across the cables and electrical connections.

16

MAINTENANCE INSTRUCTIONS

4. REMOVAL / INSTALLATION OF THE ELECTROHYDRAULIC ACTUATION MODULE

4.1 - General recommendations

CAUTION : BEFORE REMOVING THE CONTROL BACK FROM THE MACHINE, THE BLOCK AND ITS SURROUN-

DINGS MUST BE THOROUGHLY CLEANED (NOTE: DO NOT DIRECT THE JET OF A PRESSURE WASHING UNIT
DIRECTLY AT THE UNIT).

NO IMPURITIES MUST ENTER THE HYDRAULIC SYSTEM. PLASTIC PLUGS ARE TO BE FITTED ON LINES AND
ORIFICES IMMEDIATELY FOLLOWING THEIR REMOVAL.

Wear protective clothing and use suitable equipment to prevent accidents, particularly concerning the hydraulic fluid.
Use the lifting eyes and suitable handling equipment.
Set all actuators connected to the machine in neutral position (on the ground, at lower limit...) to avoid accidents which

could result from uncontrolled movements of the equipment when the hydraulic system is deconnected.
With the machine off, release the pressure remaining in the system by manipulating all of the distribution spools. This

can be performed by moving the handle in all directions.

17

MAINTENANCE INSTRUCTIONS

4.2 - Removal of a single electrohydraulic actuation
module

Machine off :

- place all of the machine’s actuators connected

to the control block in neutral position,

- release stored pressure by operating all the

spools (move the handler in all directions).

NOTE : Install a vacuum pump on the tank of the machi-

ne to limit oil leakage when connections are
removed.
After disconnecting the lines from the electrohy­draulic actuation module, immediately fit the
sealing plugs. Make sure to collect any possible
oil leakage in a suitable receptacle.

Unscrew the mounting screw using an allen wrench M5.

Reassembly : torque : 15 ± 1 N.m.

Pull the electrohydraulic actuation module backward
parallely to the spool axis in order to release the opera­tion piston.

Remove the cover of spring return system on the oppo­site side of the spool (see SX14 Maintenance instruc­tions § 6.3).

Unscrew the positionning piston from the distributing
spool using a 19mm wrench on piston side and a M5
Allen wrench on spring side.

Reassembly : Apply 2 drops of loctite 242 onto the pis-

ton thread.

torque : 10 ± 1 N.m.

18

MAINTENANCE INSTRUCTIONS

Remove and replace the tightness seal lying between
the actuator and the control valve.

Remove the centering plater.

NOTE : Do not remove the spool from the control valve.
Reassemble in reverse order.
Adjust the neutral position (see § 6).

19

MAINTENANCE INSTRUCTIONS

4.3 - Removal of one of several electrohydraulic
actuation modules assembled together

Machine off :

- Place all of the machine’s actuators connected

to the control block in neutral position.

- Release stored pressure by operating all the

spools (move the handler in all directions).

NOTE : Install a vacuum pump on the tank of the machi-

ne to limit oil leakage when connections are
removed.
After disconnecting the lines from the electrohy­draulic actuation module, immediately fit the
sealing plugs. Make sure to collect any possible
oil leakage in a suitable receptacle.

To remove an intermediary or terminal electrohydraulic
actuation module, it is required to remove the complete
module assembly.
Unscrew all the mounting screws of each electrohydrau­lic actuation modules using an Allen wrench M5 (see §

4.2).

Reassembly : torque : 15 ± 1 N.m.

Pull the module assembly backward parallely to the
spool axis in order to release the opertion piston.

Place the modules on a clean and clear surface in order
to pull them apart.

Reassembly :

- Remove and replace the carry-over pipes of the faulty

module.

- Replace the faulty electrohydraulic actuation module.

- Replace all the tighteness seals lying between the

actuators ans their control valve.

- Reassemble in reverse order.

- Adjust the neutral position (see § 6).

20

MAINTENANCE INSTRUCTIONS

4.4 - Electrohydraulique actuation module assembly

Check the cleanliness of the contact faces prior to reas­semble.
Replace the carry-over pipes that have been removed.
Replace the O-ring between the electrohydraulic actua­tion module and the control valve element.
Reassemble the module in the reverse order of opera­tions described in § 4.2 and 4.3.

4.5 - Removal / disassembly of the electrohydraulic
transformation stage

NOTE : The electrohydraulic actuation module does not
need to be removed to perform this operation.

Machine off :

- Place all of the machine’s actuators connec­ted to the control block in neutral position.

- Release stored pressure by operting all the

spools.

Once correctly installed, the unit can be placed into
operation :

- Check the condition of line connector seals.

- Check the condition of electric wires.

- Connect the lines to the block as per the connecting
diagram and tighten to the torque specification
(refer to the table in the Data sheat).

- Ensure that hoses are not twisted nor rub.

NOTE : Install a vacuum pump on the tank of the machi-

ne to limit oil leakage when connections are
removed.
After disconnecting the lines from the electrohy­draulic actuation module, immediately fit the
sealing plugs. Make sure to collect any possible
oil leakage in a suitable receptacle.

Unscrew the 4 mounting screws using an allen wrench
M3.

Reassembly : torque : 3 to 3,5 N.m.

Remove the electrohydraulic transformation stage by
gently pulling it backward parallely to the spool axis until
the rod of the position sensor is completly extracted.

NOTE : The removal of the 4 mounting screws of the

electrohydraulic transformation stage releases
the PCB tightened protecting cover. Avoid all
risk of pollution, humidification or impacts on
electronics and hydraulics parts during the
operations.

21

MAINTENANCE INSTRUCTIONS

Remove one or both electrohydraulic valve(s).
NOTE : This operation is to be performed only in the

case of an external leakage noticed around the
tightness seal between the valve and the hou­sing.

Reassembly :

- replace the external tightness seals on the valves

- fit the valve(s) into its (their) housing(s).

Replace the external tightness seal of the rod (or sensor
O-ring).

NOTE : Place the sensor O-ring in its groove on the

mechanical interface side prior to assembly.

Reassemble the electrohydraulic transformation stage in
reverse order.

Joints d'étanchéité

22

MAINTENANCE INSTRUCTIONS

5. REMOVAL / ASSEMBLY OF CONNECTING
FLANGE AND FILTER

Machine off :

- Place all of the machine’s actuators connec­ted to the control block in neutral position.

- Release stored pressure by operating all the
spools.

NOTE : Install a vacuum pump on the tank of the machi-

ne to limit oil leakage when connections are
moved.
After disconnecting the lines from the electrohy­draulic actuation module, immediately fit the
sealing plugs. Make sure to collect any possible
oil leakage in a suitable receptacle.

5.1 - Connecting flange removal / assembly

Unscrew the 2 mounting screws using an allen wrench
M5.
Reassembly : torque : 11 ± 1 N.m.

Remove the connecting flange. Pull the connecting flan­ge backward parallely to the screw axis in order to relea­se the carry-over pipes.

Reassemly :

- Replace carry-over pipes.

- Reassemble parts in reverse order.

5.2 - Filter replacement

Unscrew the filter in the port P using a flat screw driver.

Reassembly : hand tight the filter in port P.

23

MAINTENANCE INSTRUCTIONS

6. NEUTRAL POSITION ADJUSTMENT

NOTE : To perform this operation, the control block does

not need to be removed from the machine, nor
the electrohydrauic actuator module from the
control valve.

Machine off :

- Place all of the machine’s actuators connected
to the control block in neutral position.

- Release stored pressure by operating all the

spools (move the handler in all directions).

Locate and remove the inspection plug on the lower side
of the actuation module rear cover.
Switch on the electrical power (12VDC or 24VDC) only
(no hydraulic power).
The assistance pressure of 35 bar must absolutely be
decompressed.

Locate the adjusting trimmer inside and the green LED
underneath. The green LED will turn on by the time the
”mechanical zero” of the spool matches the ”electrical
zero” of the electronic setup.

Using a flat and thin screwdriver, turn the trimmer clock­wise or counterclockwise until the green LED turns on.

24

MAINTENANCE INSTRUCTIONS

7. START UP PROCEDURES

Machine off :

- Place all of the machine’s actuators connected to the control block in neutral position.

- Release stored pressure by operating all the spools. Make sure that the remote control is switched off
while starting up the engine and before the hydraulic pump is engaged.

Start up the engine and engage the oil pump. Turn on the remote control system.

CAUTION

THE ELECTROHYDRAULIC PROPORTIONAL SYSTEM IS DESIGNED AND QUALIFIED FOR LOW TEMPERATURE
OPERATION UP TO -40°C. FOR OIL TEMPERATURE LESS THAN -15°C, ACTUATORS MOVEMENTS MAY INITIAL­LY RESULT SLOW AND JERKY. IT IS STRONGLY RECOMMANDED THAT COLD WEATHER START-UP ARE FOL­LOWED BY PROPER OIL HEATING PROCEDURES.

Engage the remote control device and slowly vary the control signal making sure that no external obstacle can be hit in
case of unadverted movements.

In response to a variable signal generated by the remote control device, the selected machine’s function must smoothly
accelerate / decelerate, showing good stability and repeatability.

When one remote control function at a time is engaged, only the corresponding machine function must respond, while all
the other machine functions remain at rest.

25

50

Transmission control and adjustment

6 - SPRUNG-ON 4 WHEEL DRIVE DIS-ASSEMBLY AND RE-ASSEMBLY

DIS-ASSEMBLY

6-1

The sprung on 4 wheel drive assembly.

6-2

Position the shaft in a soft jawed vice
and remove the sealing ring.

6-3

Using the appropriate bearing puller
remove the rear bearing.

6-5

6-4

Remove the thrust washer.

6-6

Remove the 4 wheel drive gear.

Remove the two needle bearings and
spacer.

(01/07/2008)

6-7

Invert the shaft and using the appropriate
bearing puller remove the front bearing.

Transmission control and adjustment

6-8

Using the appropriate tool compress the
spring and release the circlip.

51

6-9

Remove the circlip, retainer, and spring.

6-11

6-10

Remove the piston drum assembly.

6-12

Remove the piston seal and «O»ring from
the shaft and discard.

(01/07/2008)

Remove and discard the piston seal and
«O»ring from the piston drum.

52

Transmission control and adjustment

RE-ASSEMBLY

6-13

Fit a new «O»ring and sealing ring to the
shaft.
See (fi g. 6-11).

6-14

Fit a new «O»ring and sealing ring into the
piston. Bend the sealing ring into a heart
shape as shown to assist assembly.

6-15

Lubricate the seals with a light grease
and refi t the piston to the shaft.

6-17

6-16

Replace the piston spring and retainer.

6-18

Using the appropriate tool compress the
spring and retainer and refi t the circlip.

Using an appropriately sized tube refi t
the front bearing.

(01/07/2008)

6-19

Invert the shaft and refi t the two needle
bearings and spacer as shown.

Transmission control and adjustment

6-20

Replace the 4 wheel drive gear.

53

6-21

Replace the thrust washer.

6-23

6-22

Using an appropriately sized tube replace
the rear bearing.

Fit a new sealing ring.

(01/07/2008)

54

Transmission control and adjustment

7 - PERMANENT 4 WHEEL SHAFT DIS-ASSEMBLY AND RE-ASSEMBLY

DIS-ASSEMBLY

7-1

The permanent 4 wheel drive shaft.

7-2

Using the appropriate bearing puller
remove the front and rear bearings.

7-3

Remove the 4 wheel drive gear.

RE-ASSEMBLY

7-4

Replace the 4 wheel drive gear using
stop threaded product (P / N° 548110),
on the shaft splines . Then using a
suitably sized tube re-fi t the front and
rear bearings.

(01/07/2008)

Transmission control and adjustment

8 - DIS-ASSEMBLY AND RE-ASSEMBLY OF THE OIL PUMP

Note : Individual components of the oil
pump are non serviceable. The pump
may, however, be stripped for cleaning
and examination purposes.

8-1

View showing a dismantled pump
assembly.

55

8-2

The pump oil seal may be replaced using
an approprietely sized tube.

(01/07/2008)

56

Transmission control and adjustment

9 - DIS-ASSEMBLY AND RE-ASSEMBLY OF THE VALVE

Nota : Dis-assembly of the control valve

is not generally recommended
as, with the exception of the
solenoids, individual parts are
non serviveable. It may however
be dismantled for cleaning and
examination.

9-1

The retaining nut, coil and washers
removed.

9-2

The modulation components removed.

9-3

There are 4 «O»rings fi tted to the
underside of the valve which may be re­newed if necessary.

(01/07/2008)

Transmission control and adjustment

10 - GEAR LEVER HOUSING DIS-ASSEMBLY AND RE-ASSEMBLY

10-1

Remove the plastic ties from the rubber
gaiter and pull the assembly apart as
shown.

Nota : Before re-assembly remove all

traces of old sealant from the
joint faces.

57

10-2 10-3

Apply a airtightness product (P / N°

562228) to the sealing face as shown.

Lubricate the ball seating with a light
grease and push the two halves of the
assembly together. Secure the rubber
gaiter with two new plastic ties.

(01/07/2008)