Thomas 135 Operating instructions

REPAIR MANUAL
135
137
153
1300 ProTough
Publication No. 49702
September , 2004
THOMAS

2
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 CLAIMING ANY
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 49702

3
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 into the main frame inside the rear door.
FOREWORD
C4223
S/N Stamp Location
S/N Tag location.
Tag is found on
opposite side on
some models

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.
*EYEPROTECTION
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.
*HEARINGPROTECTION
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.
*FOOTPROTECTION
Substantial or protective footwear with
reinforced toecaps will protect the feet from
falling objects.
*SPECIALCLOTHING
For certain work it may be necessary to wear
flame or acid resistant clothing.
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.
*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.
SAFETY PRECAUTIONS
CAUTION
Avoid injury through incorrect handling of
components. Make sure you are capable of lifting
the object. If in doubt, get help.
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.
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.
*HOUSEKEEPING
Many injuries result from tripping or slipping
over, or on, objects or materials left lying around
by a careless worker.
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.
*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.
SAFETY PRECAUTIONS
5

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 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.
*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
6

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.
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.
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.
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.
SAFETY PRECAUTIONS
7

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.
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.
SAFETY PRECAUTIONS
8

9
Section 1 Hydraulic System
Hydraulic Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.1
Gear Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.2
Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.3
Hydraulic Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.4
Oil Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.5
Oil Cooler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.6
Oil Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.7
Trouble Shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.8
Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.9
Conversion Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.10
Section 2 Hydrostatic Drive System
Hydrostatic 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 Specifications........................................................................2.13
Section 3 Final Drive
Specifications and Maintenance ........................................................3.1
Lubrication.........................................................................................3.2
Drive Chain........................................................................................3.3
Chain Tightener..................................................................................3.4
Drive Motor Sprocket........................................................................3.5
Axle Assembly...................................................................................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
TABLE OF CONTENTS

10
Section 5 Electrical
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .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
Decals.................................................................................................8.5
TABLE OF CONTENTS

1-1
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 (137/153) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-7 ~11
Gear Pump Reassembly (137/153) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-12 ~ 14
Gear Pump Disassembly (1300/135) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pg. 1-15 ~ 17
Gear Pump Reassembly (1300/135) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pg. 1-18 ~ 20
Control Valve 1.3
Testing / Adjusting the Relief Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-21 ~ 22
Control Valve Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-22 ~ 23
Exploded Illustration Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-24 ~ 25
Control Valve Disassembly / Repair(137/153) . . . . . . . . . . . . . . . . . . . . . . . pg. 1-26 ~ 31
Control Valve Disassembly/Repair(1300/135) . . . . . . . . . . . . . . . . . . . . . . . .pg. 1-32~ 35
Hydraulic Cylinders 1.4
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pg. 1-36
Testing Piston Seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-37
Lift Cylinder Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-38
Tilt Cylinder Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-39
Cylinder Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-40 ~ 41
Cylinder Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-42
Cylinder Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-42 ~ 43
Hydraulic Oil Filter 1.5
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-44
Filter Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-44
Hydraulic Oil Cooler 1.6
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pg. 1-45
Oil Cooler Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pg. 1-45
Hydraulic Oil Reservoir 1.7
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-46
Checking the Oil Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-46
Adding Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-46
Servicing the Reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-47
Trouble Shooting 1.8
Trouble Shooting Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-48 ~ 49
Torque Chart 1.9
Torque Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1~49
Conversion Charts 1.10
Conversion Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg. 1-50

1
HYDRAULIC LAYOUT 1.1
AAuxiliary Circuit
BTilt Circuit
CLift Circuit
NOTE: Foot pedal control operated machine illustrated.
Items (A3 / B3) are reversed for hand control operated
machines.
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
B B
AA
C C
C4224

1
HYDRAULIC SCHEMATIC 1.1
1-3
C4475

1
1-4
SPECIFICATIONS & MAINTENANCE 1.1
Maintenance Schedule . . . . . . . . . First (HRS) . . . . Every (HRS)
Oil level check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 . . . . . . . . . . . . . . . . . . . . . 8
Oil filter change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 . . . . . . . . . . . . . . . . . . . . 150
Oil cooler clean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 . . . . . . . . . . . . . . . . . . . . . 8
General system check
( leaks etc. ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 . . . . . . . . . . . . . . . . . . . . . 8
Cylinders, lubricate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 . . . . . . . . . . . . . . . . . . . . . 8
Control valve relief filter . . . . . . . . . . . . . . . . . . . . . . . 500 . . . . . . . . . . . . . . . . . . . 1000
Reservoir filters change . . . . . . . . . . . . . . . . . . . . . . . 1000 . . . . . . . . . . . . . . . . . . 1000
Hydraulic oil change . . . . . . . . . . . . . . . . . . . . . . . . . 1000 . . . . . . . . . . . . . . . . . . 1000
Hydraulic Specifications
Pump Type . . . . . . . . . . . . . .137/153 (Sauer-Danfoss) Gear, 1.37 cu in (22.5cc)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1300/135 (Eaton) / 1.2 cu in (19.7cc)
Pump Brand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sauer Danfoss / Eaton
Pump Capacity . . . . . . . . . . . . . . . . . . . . . . . .137/153 16.6 gal/min (62.8 l/min)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1300/135 14.5 gal/min (54.9 l/min)
Control Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Series Type
Main Relief Pressure . . . . . . . . . . . . . . . . . . . 2400 psi (165.5 bar) @ Zero Flow
Reservoir Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 US gallons (30.3 liters)
Fluid Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10W30 API SJ Oil
Reservoir Filtration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Micron
System Filtration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Micron
Oil Cooler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .137/153 674 BTU
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1300/135 440 BTU
Lift Cylinders 153 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (2) 2.5’’ Bore Diameter
Lift Cylinder Rods 153 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5’’ Diameter
Lift Cylinders 137/135/1300 . . . . . . . . . . . . . . . . . . . . . . . (2) 2’’ Bore Diameter
Lift Cylinder Rods 137/135/1300 . . . . . . . . . . . . . . . . . . . . . . . . 1.25’’ Diameter
Tilt Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (2) 2 1/2’’ Bore Diameter
Tilt Cylinder Rods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.125’’ Diameter
Lift Cycle HD 135/153 Cyl. + / - 1.5 seconds (Up / Down) . . . . . . . 4.39 / 3.25
Lift Cycle STD 1300 Cyl. + / - 1.5 seconds (Up / Down) . . . . . . . . . 3.19 / 2.05
Tilt Cycle + / - 1.5 seconds (Up / Down) . . . . . . . . . . . . . . . . . . . . . . 2.20 / 2.50
Allowable Drop, Measured at the Cylinder Rod, Engine Off,
@ Rated Capacity and Operating Temperature . . . . . . 1.5’’ (38mm) / 3 Minutes

1
GENERAL INFORMATION 1.1
Refer to figure C2018 on page 1-2.
Oil is drawn from the hydraulic oil reservoir through a
100 micron element. From there it travels to the main
hydraulic pump.
•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.
•The hydraulic control valve is equipped with an
adjustable relief valve which is adjusted to 2400 psi
(165.5 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 hydraulic cooler, to the 5 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. As a spool is moved, oil is directed to one of
the valve ports and oil flows out to operate a function.
The return oil coming back from this operation is ported
to the next valve section which allows operation of more
than 1 function at the same time. This is a series type
valve function.
Each spool end contains a centering spring which returns
the spool to neutral when the foot pedal, or control
handle, is released.
•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. C3746).
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
2400 psi (165.5 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 (fig. C3717).
C3746
C3717
1-5
Relief Valve
Load Check Valve
Control valve location
Gear pump location
C4226
C4223

1
1-6
GEAR PUMP 1.2
Start the gear pump removal procedure by removing any
attachment, raising the boom arms and engaging the
boom support pins. Shut off the engine.
1Remove the seat and hydrostatic shield.
2Attach a vacuum system to the hydraulic oil reservoir
filler location. ( fig. C4227 ) 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.
3Disconnect the hydraulic hoses from the gear pump.
( fig. C4228 ) Remove the pump fittings. Cap all open
hoses to prevent contamination. After capping ends you
may unhook vacuum system from oil reservoir.
4Remove the 2 bolts holding the gear pump to the
hydrostatic tandem section. ( fig. C4228b) Remove the
gear pump.
5Replace gear pump in reverse order.
6If the hydraulic system has been contaminated by
pump or other failure you must follow the cleaning
procedure outlined in section 2.7.
7Start the engine and check for leaks. Do not use your
hands to find leaks.
8Check the fluid level in the hydraulic oil reservoir
and replenish as required. (fig. C1878)
Replacement
WARNING
To prevent personal injury do not work under the
boom arms without the boom supports engaged.
WARNING
Use caution when dealing with hydraulic fluid under
pressure. Escaping fluid under pressure can
penetrate the skin and cause serious injury.
If gear pump replacement is being done because of
failure, the hydraulic system and oil should be
checked for contamination.
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.
IMPORTANT
C4227
Reservoir filler spout
Vacuum hose
C4228
Hoses
C4228b
Bolts
C1878
Oil level

1
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 sub-
assemblies 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.
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.
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.
IMPORTANT
1-7

1
1. Screws 8. Drive Shaft
2. Cover Assembly 9. Wear Plate
3. Seal Ring 10. Load Ring
4. Wear Plate 11. Preload Ring
5. Gear Plate 12. Seal Ring
6. Dowel Pin 13. Body Assembly
7. Idler Shaft 14. Shaft Seal
1-8
Disassembly 137/153
GEAR PUMP 1.2
1
3
2
4
5
10
11
7 6
8
9
C4347
13
12
14

1
1-9
C4350
C4351
Disassembly 137/153
C4348
C4349
GEAR PUMP 1.2
6. Procedure
1. Clamp the unit in a vice from the flange side
(fig. C4348). Make sure the vice jaws are clean and
have smooth surfaces to prevent damage to the
pump. Caution must be used when using a vice to
avoid distorting any parts or damaging the mounting
pilot.
2. Use a Allen head socket wrench to loosen the
bolts on the cover assembly (fig. C4349). Next
completely unscrew the bolts and remove them.
Inspect the threads for damage (fig. C4350).
3. Slowly remove the cover assembly (fig. C4351).
Note, some units have a shaft seal and others do not.
Should your unit have the shaft seal, be careful not to
damage it when removing the cover assembly.
Vice
Bolts
Remove
bolts and
inspect for
damage.
Front Flange

1
C4352
C4353
C4354
Disassembly 137/153 (cont’d)
1-10
GEAR PUMP 1.2
6. Procedure
4. Place the cover assembly on the work bench
(fig. C4352). Inspect the wear plate for evidence of
extrusion or marks caused by overheating. Replace
if necessary. Remove the wear plate and seal ring on
the cover assembly. Do not use tools with sharp
edges to remove the seal, as damage to the housing
may result.
5. While disassembling the unit, you need to mark
the relative positions of the gear mesh (drive gear
tooth and idler gear tooth) and the body so they can
be reassembled in the same position. Carefully
remove the gear plate (fig. C4353). Remove the
dowel pins and place in the gear plate.
6. Remove the idler shaft and drive shaft from it’s
bearing bore. Inspect the journals and the flat faces
top and bottom of the gears. Ensure these surfaces
are free from burrs or scratches. If scratches are
found, clean them with a flat stone and/or a very fine
emery cloth. Rewash the gears with light oil after
this operation.
Wear Plate
Seal Ring
Idler Shaft
Drive Shaft
C4355