TUG M3 Operation manual

Overhaul

Chapter 3: Overhaul Sept. 1995 p. 1
CHAPTER 3
TABLE OF CONTENTS
CHAPTER/SECTION PAGE
OVERHAUL
I. RECOMMENDED OVERHAUL PERIODS 3 - 1 1
A. GENERAL.....................................................................................................................................1
B. HYDRAULIC PUMP ......................................................................................................................1
C. DISC BRAKE CALIPERS..............................................................................................................1
D. BRAKE BOOSTER PUMP............................................................................................................1
E. MASTER CYLINDER....................................................................................................................1
F. PLANETARY REDUCTION HUBS................................................................................................1
II. STEER AXLE 3 - 2 1
A. DISCUSSION................................................................................................................................1
B. INSPECTION AND OVERHAUL...................................................................................................1
III. HYDRAULIC PUMP 3 - 3 1
A. DISCUSSION................................................................................................................................1
B. HYDRAULIC (STEERING) PUMP ASSEMBLY REMOVAL:......................................................... 1
C. HYDRAULIC (STEERING) PUMP ASSEMBLY INSTALLATION: .................................................1
IV. MASTER CYLINDER DISASSEMBLY AND ASSEMBLY 3 - 4 1
A. MASTER CYLINDER REMOVAL..................................................................................................1
B. DISASSEMBLY .............................................................................................................................1
C. INSPECTION AND REPAIR .........................................................................................................2
D. ASSEMBLY ...................................................................................................................................2

Chapter 3: Contents Sept. 1995 p. 2
IV. MASTER CYLINDER DISASSEMBLY AND ASSEMBLY 3 - 4 1
E. BLEEDING THE MASTER CYLINDER.........................................................................................3
F. MASTER CYLINDER INSTALLATION ..........................................................................................3
V. FOUR WHEEL DISC BRAKES 3 - 5 1
A. BRAKE PAD REPLACEMENT......................................................................................................1
1. Preparation:.......................................................................................................................... 1
2. Rear Caliper Removal..........................................................................................................1
3. Brake Pad Removal .............................................................................................................2
4. Cleaning and inspection:......................................................................................................2
5. Brake Pad Installation ..........................................................................................................4
6. Caliper Installation................................................................................................................4
7. Check-Out: ...........................................................................................................................5
B. CALIPER OVERHAUL ..................................................................................................................6
1. General Layout; Front ..........................................................................................................6
2. Removal...............................................................................................................................6
3. Disassembly .........................................................................................................................7
4. Cleaning and Inspection.......................................................................................................8
5. Reassembly.......................................................................................................................... 8
6. Installation ............................................................................................................................9
7. Check-Out: ...........................................................................................................................9
C. FRONT ROTOR............................................................................................................................9
1. Rotor Removal ..................................................................................................................... 9
2. Cleaning .............................................................................................................................10
3. Inspection ...........................................................................................................................10
4. Reassembly........................................................................................................................ 10
5. Installation ..........................................................................................................................10
6. Check Out ..........................................................................................................................10
D. BLEEDING THE DISC BRAKE SYSTEM ...................................................................................11
1. General ..............................................................................................................................11
2. Manual Bleeding.................................................................................................................11
3. Pressure Bleeding .............................................................................................................. 11
4. Check-Out ..........................................................................................................................12
E. REAR WHEEL DISK BRAKE SPECIFICS .................................................................................12
1. Caliper Removal ................................................................................................................12
2. Rear Caliper Assembly.......................................................................................................13

Chapter 3: Overhaul Sept. 1995 Section 3-1 p. 1
I. Recommended Overhaul Periods
A. GENERAL
The following overhaul periods are approximate and can vary greatly due to different operating
conditions. Units operating in extreme conditions such as high or low temperatures, long periods
of sustained operation, continued operation in sand or dust or continued exposure to sea air or
moisture require careful, regular inspections. Overhaul periods may be adjusted with time and
experience in operating this tractor. If an overhaul of a component or system is anticipated or
required, the procedures that cover that component or system should be read and fully under-
stood prior to attempting any part of the overhaul.
B. HYDRAULIC PUMP
Overhaul when internal or external leakage is evident or after 5,000 hours.
C. DISC BRAKE CALIPERS
Calipers should be overhauled if piston seizure is evident, if leakage occurs around piston boot
or if uneven braking persists after troubleshooting brake lines.
D. BRAKE BOOSTER PUMP
Booster pump components (i.e. pump section and motor section) can be replaced more easily
and economically than overhauling. Refer to troubleshooting section to isolate brake booster
problems.
E. MASTER CYLINDER
Refer to troubleshooting section to isolate problems with master cylinder. Master cylinder should
be rebuilt if piston gasket damage is evident and when significant brake pressure is being lost
after all other possible causes have been eliminated.
F. PLANETARY REDUCTION HUBS
Hubs should pass roll test and leak test before being deemed service worthy. Refer to Final
Drives supplement, chapter 5.

Chapter 3: Overhaul Sept. 1995 Section 3-1 p. 2
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Chapter 3: Overhaul Sept. 1995 Section 3-2 p. 1
II. STEER AXLE
A. DISCUSSION
If tractor has been properly lubricated and maintained and has not experienced damage to the
steering system, the steering components will provide many hours of service without an over-
haul. Should overhaul be required, follow the procedure below:
WARNING: OBSERVE ALL SAFETY PRECAUTIONS DISCUSSED IN THE SAFETY SEC-
TION OF THIS MANUAL!
B. INSPECTION AND OVERHAUL
Jack up the front end of the tractor using normal jacking procedures (i.e., chock rear tires, apply
hand brake, and place blocks under tractor front bumper).
Inspect the steering linkage rod for damage. Also check for wear of the linkage rod ball joints by
grasping the rod and shaking it. If the linkage rod ball joints are loose, replace the rod.
1. Bearings and Seals
Grasp the top and bottom of each tire and shake it in and out while observing the hub and
spindle area to detect any wobble or looseness. If any wobble or looseness is noted in the
hub and the spindle is rigid, the wheel bearings and seals should be adjusted by tightening
the hub retainer nut. If excessive noise is experienced after adjustment, the bearings and
seals should be replaced as follows:
(a) Remove the front wheels by removing the lug nuts on each wheel.
(b) Remove disc brake caliper.
(c) Remove the grease cap, cotter pin, outer hub retainer nut, nut lock and inner hub
retainer nut.
(d) Grasp the hub and slide it off the axle shaft.
(e) Remove the inner and outer seals and bearings from the hub and wipe the hub
interior clean.
(f) Inspect hub interior surfaces (bearing races) for scoring. If the races are scored or
worn, replace with new races.
(g) Install new bearings and seals into the hub, packing the bearings with lithium-based
grease, and replace the hub onto the axle shaft.
(h) Replace caliper.
(i) Secure the hub with the retainer nuts and nut lock and replace the hub cap.
(j) Install the wheel.

Chapter 3: Overhaul Sept. 1995 Section 3-2 p. 2
II. STEER AXLE
B. INSPECTION AND OVERHAUL (CONT):
2. A-Arm Bushings Removal/Replacement:
Note: This procedure written with the assumption that both sets of bushings to be changed.
Spindle assemblies do not have to be removed for this procedure, however a-arms will be quite
heavy. Procedure is written as if spindles are to be left intact on a-arms.
a. Chock rear tires, jack front end of vehicle. Secure front with jackstands under front
frame.
b. Remove tires.
c. Remove tie rod. Note: Use jack stands, floor jacks or individual jack stands to
support a-arms before disconnecting tie rod.
d. Remove calipers:
(1) Remove upper king pin cover (two bolts).
(2) Unbolt and tie-off calipers.
e. Remove lower shock bolt. Note: This bolt also holds bottom link of spring limiter
chains.
f. Remove (2) main a-arm pivot bolts. Remove a-arm assembly.
g. Remove old bushings; press-in new bushings.
Note that bushings are located at the tips of the U-shape. The span between the U-
tips must be bridged so that arms are not bent during pressing. Rig a secure steel
bridge between the arms, or contact Tug Manufacturing regarding special tooling.
h. Reassemble a-arm(s) but do not tighten pivot bolts.
i. Rotate a-arm into place, attach bottom shock bolt with chain limiter. Tighten
securely.
j. Tighten a-arm pivot bolts securely.
k. Reassemble remaining components in reverse order from disassembly.
3. Tie Rod Ends:
Grasp the sides of the wheel and shake it from side to side while observing the rod ends. If
excessive movement is observed in the rod connection ends, replace the connecting rod
ends as follows:

Chapter 3: Overhaul Sept. 1995 Section 3-2 p. 3
(a) Disconnect the rod ends from the spindle arms, removing the cotter pins and
retainer nuts.
(b) Remove the connecting rod and remove the rod end retainer clamps.
(c) Screw the new rod ends approximately 1/4 inch into each end of the rod.
(d) Install the connecting rod to the spindle arms, securing the connecting rod ends to
the spindle arms with the two (2) retainer nuts and cotter pins.
(e) With the wheels pointing straight forward, adjust the “toe-in” by turning the
connecting rod until the centerline-to-centerline distance across the back of the tires
is 0 to 1/8 inch longer than the centerline-to-centerline distance across the front of
the tires.
(f) After the toe-in adjustment has been accomplished, install the rod end clamps,
securing the connecting rod adjustment.

Chapter 3: Overhaul Sept. 1995 Section 3-2 p. 4
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Chapter 3: Overhaul Sept. 1995 Section 3-3 p. 1
III. HYDRAULIC PUMP
A. DISCUSSION
Hydraulic pump should be overhauled after 5000 hours or when internal or external leakage is
evident. The hydraulic pump assembly can be divided into three main components. (Refer to
figure on page 2). Reservoir, pump section & motor. Disassemble and replace all worn or
damaged parts.
B. HYDRAULIC (STEERING) PUMP ASSEMBLY REMOVAL:
CAUTION! SIDE PANELS ARE HEAVY! REMOVE CAREFULLY
1. Disconnect battery, remove right side access panel.
2. Disconnect electrical wiring.
3. Remove (4) mounting bolts: Use long extension rachet and matching wrenches below
tractor.
CAUTION: WIPE ALL CONNECTIONS CLEAN PRIOR TO OPENING SYSTEM.
CAUTION: CAP OR PLUG ALL OPEN PORTS AND LINES.
NOTE: USE BACK UP WRENCHES ON ALL MATING FITTINGS.
4. Gently rotate pump to reveal access to hydraulic line connections.
5. Use tape to label lines (in & out).
6. Remove hydraulic lines at elbows.
7. Remove pump & reservoir assembly.
C. HYDRAULIC (STEERING) PUMP ASSEMBLY INSTALLATION:
1. Place pump & reservoir assembly into floor of right side service bin, reservoir end toward
rear of vehicle.
2. Attach hydraulic lines at elbows.
3. Attach assembly to floor using (4) mounting bolts: Use long extension rachet and matching
wrenches below tractor.
4. Connect electrical wiring.
5. Top off hydraulic fluid in reservoir.
6. Replace right side access panel.

Chapter 3: Overhaul Sept. 1995 Section 3-3 p. 2

Chapter 3: Overhaul Sept. 1995 Section 3-3 p. 3
Ref. Part Description No.
No. No. Req'd
1 03142 PUMPASSEMBLY,Gear Code62 1
02625 PUMPASSEMBLY,Gear Code51 1
02650 PUMPASSEMBlY,Gear Code43 1
02624 PUMPASSEMBlY,Gear Code42 1
02629 PUMPASSEMBLY,Gear Code05 1
02659 PUMPASSEMBLY,Gear Code03 1
2. 02352 O-RING,Industrial (3-5/8x 3-7/8 x1/8) 1
3. 00075 PARTS KIT, Check Valve(main) 1
4. 02159 SEAL 1
5. 03766 PARTS KIT, Relief Valve 1
6. 03427 SWITCH,Solenoid, 12VDC,3-post groundedto can 1
03481 SWITCH,Solenoid, 12VDC3-post (coated)groundedto can 1
03336 SWITCH,Solenoid, 12VDC,3-post insulatedground 1
03340 SWITCH,Solenoid, 12VDC,3-post (coated)insulatedground 1
03335 SWITCH,Solenoid, 12VDC4-post isolatedground 1
03342 SWITCH,Solenoid, 12VDC4-post (coated)isolatedground 1
03467 SWITCH,Solenoid, 24VDC,3 post,grounded to can 1
03652 SWITCH,Solenoid, 24VDC,3 post,(coated) grounded tocan 1
03343 SWITCH,Solenoid, 24VDC3 postinsulatedground 1
03344 SWITCH,Solenoid, 24VDC3 post(coated)insulated ground 1
7. 01349 STRAP,Motor-Solenoid 1
8. 07683 SCREW, Round HeadMachine 10-32 x1/4 2
9. 08111 MOTOR, Electric, 12 VDC 1
08112 MOTOR, Electric, 12 VDC 1
08120 MOTOR, Electric, 24 VDC 1
10. 02318 BEARING,Base,motor 1
11. 07625 NUT, Hex 5/16-24 1
12. 07781 WASHER, Lock 5/16" 1
13. 07737 WASHER, Star 1/4" 4
14. 07795 WASHER, Lock 1/4" 2
15. 07738 SCREW, HexHeadCap 1/4-20x6-1/2" 2
16. 02238 BRACKET, Mounting 1
17. 04559 BRACKET, Plate Mount 5.00" C to C 1
04560 BRACKET, Plate Mount 3.25" C to C 1
18. 07894 SocketHeadCap,Thread forming,torxdrive, 5/16-18 x1-1/8 2
19. 07717 SCREW,Hex Head,threadforming 1/4-20x1-3/8 2
20. 01134 SCREEN,Filter (suction) 1
21. 01209 TUBE, Filter Suction 3/8 NPT 90 Deg. 1
22. 01329 ADAPTER,PumpMountingBracket 1
23. 01274 TUBE, Return (1/8 NPT) 1
24. 06661 RESERVOIR, 4-1/2" Dia. x 8", 76 cu in usable 1
06663 RESERVOIR, 4-1/2" Dia. x 10", 102 cu in usable 1
06665 RESERVOIR, 4-1/2" Dia. x 12", 127 cu in usable 1
25. 06678 RESERVOIR, 5" x 5" x 10", 211 cu in usable1
06663 RESERVOIR, 5" x 5" x 12", 249 cu in usable 1
06665 RESERVOlR, 5" x 5" x 15", 306 cu in usable1
26. 01143 PLUG,Vent (plastic) 1
03866 PLUG, Vent, 3/8" NPT 1
27. 01482 TUBE ASSEMBLY, Downspout,return(1/4 NPTMxF) 1
28. 07703 SCREW, ThreadForming10-24 x3/8" 6

Chapter 3: Overhaul Sept. 1995 Section 3-3 p. 4
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Chapter 3: Overhaul Sept. 1995 Section 3-4 p. 1
IV. MASTER CYLINDER DISASSEMBLY AND ASSEMBLY
A. MASTER CYLINDER REMOVAL
1. Open Console door.
2. Remove brake lines from cylinder body.
3. Plug brake line ports or drain brake fluid into appropriate container.
4. Remove (2) mounting bolts and nuts.
5. Slide master cylinder off of push rod.
When it is necessary to repair the master cylinder during the warranty period, replace the
cylinder as a unit instead of overhauling the cylinder with a service repair kit.
B. DISASSEMBLY
1. Clean the outside of the master cylinder and remove the reservoir cover and reservoir
diaphragm. Drain any fluid left in the cylinder. Be careful with brake fluid as it damages
painted surfaces.

Chapter 3: Overhaul Sept. 1995 Section 3-4 p. 2
IV. MASTER CYLINDER DISASSEMBLY AND ASSEMBLY
B. DISASSEMBLY(CONT)
2. Remove the push rod boot (if equipped), from the groove at the rear of the master cylinder,
and slide the boot away from the rear of the master cylinder.
3. Remove the snap ring holding the pistons in the cylinder body.
4. Remove the push rod (if equipped), and primary piston assembly from the master cylinder.
Discard the piston assembly, including the boot (if equipped).
WARNING: USE LOW AIR PRESSURE TO REMOVE THE PISTON. HIGH PRESSURE
COULD RESULT IN DAMAGE OR PERSONAL INJURY.
5. Using an air hose in the rear brake outlet port of the cylinder body, carefully blow the
secondary piston out of the cylinder body. Remove the return spring, spring retainer, cup
protector and cups from the secondary piston. Discard the cup protector and cups.
C. INSPECTION AND REPAIR
1. Clean all parts in clean isopropyl alcohol or Rotunda Brake Parts Washer (model 650016)
or equivalent, and inspect the parts for chipping, excessive wear or damage. Replace
them, if necessary. When using a master cylinder repair kit, use all the parts provided.
2. Check all recesses, openings and internal passages to be sure they are open and free of
foreign matter.
3. Inspect the hydraulic master cylinder bore for etching, pitting or rust. Replace the master
cylinder if any of these conditions exist.
D. ASSEMBLY
1. Remove the master cylinder from the vise. Check the outlet ports for brass burrs and
remove, if present.
2. Dip all the parts except for the cylinder body in clean ESA-M6C25-B extra heavy duty
brake fluid or equivalent and lubricate the bore walls with brake fluid.
3. Assemble the secondary cup and 0-ring back-to-back in the grooves near the end of the
secondary piston. Assemble the cup protector, primary cup, spring retainer and secondary
piston return spring on the other end of the secondary piston.
4. Install the secondary piston assembly in the master cylinder. Wet the seals with the brake
fluid and use caution when inserting the piston assemblies into the bore to prevent damage
to the seals.

Chapter 3: Overhaul Sept. 1995 Section 3-4 p. 3
5. Install the primary piston assembly in the master cylinder. Push the primary piston inward
and tighten the secondary piston stop bolt to hold the secondary piston in the bore.
6. Position the stop plate and snap ring on the primary piston. Depress the primary piston and
install the snap ring in the cylinder body.
7. Bleed the master cylinder.
E. BLEEDING THE MASTER CYLINDER
Before installing the master cylinder on the vehicle, bleed the unit as follows:
1. Support the master cylinder body in a soft-jawed vise and fill both fluid reservoirs with
ESA-M6C25-A extra heavy duty brake fluid or equivalent.
2. Install plugs in the front and rear brake outlet ports. Bleed the rear brake system first.
3. Loosen the plug in the rear brake outlet port. Depress the primary piston slowly to force the
air out of the master cylinder. Tighten plug while piston is depressed to prevent air from
entering the master cylinder.
4. Repeat this procedure until air ceases to exit at the outlet port.
5. Repeat steps (3) and (4) for the front brake outlet port with the rear brake outlet plugged.
6. Tighten the plugs and attempt to depress the piston. The piston will resist depression after
all air is expelled.
7. Install the cover and diaphragm assembly, being sure the cover retainer is tightened
securely. Remove the plugs.
F. MASTER CYLINDER INSTALLATION
1. Open Console door.
2. Slide master cylinder onto push rod.
3. Mount cylinder body using (2) mounting bolts and nuts.
4. Unplug cylinder brake line ports.
5. Attach brake lines to brake line ports.

Chapter 3: Overhaul Sept. 1995 Section 3-4 p. 4
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Chapter 3: Overhaul Sept. 1995 Section 3-5 p. 1
V. FOUR WHEEL DISC BRAKES
The following illustrations and procedures apply specifically to the M3 front disc brakes. To
accomodate the specific requirements of the specialized rear end, a different brake caliper has been
designed into the M3 rear disk brakes. In general, the following procedures can be applied to the rear
brakes as well. For specific rear brake information, refer to section E at the end of this section.
A. BRAKE PAD REPLACEMENT
Inspect the brake linings any time that the wheels are removed. Check both ends of the out-
board pad by looking in at each end of the caliper. These are the points at which the highest rate
of wear normally occurs. However, at the same time, check the lining thickness of the inboard
pad to make sure that it has not worn prematurely. Look down through the inspection hole in the
caliper to view the inboard pad. Whenever the thickness of any lining is worn to the approximate
thickness of the metal backing, all pads on the axle should be replaced.
1. Preparation:
For front service, chock rear wheels and raise front of vehicle. For rear service, chock
front tires and raise rear.
2. Front Caliper Removal
(a) Remove 2/3 of brake fluid from master cylinder reservoir.
(b) Push the piston back into its bore. This can be accomplished by using a C-clamp.
(c) Using 3/8" allen wrench, loosen and remove (2) mounting (retainer) bolts (see figure
1). Lift the caliper off the rotor and position on drive axle so that the brake hose will
not support the weight of the caliper.
Figure 1

Chapter 3: Overhaul Sept. 1995 Section 3-5 p. 2
V. FOUR WHEEL DISC BRAKES
A. BRAKE PAD REPLACEMENT
2. Caliper Removal (cont.):
NOTE: If only brake pads and linings are being replaced, omit step (d).
(d) Disconnect brake line from caliper and plug openings in caliper and line to prevent
fluid loss and to keep out contamination. (See Figure 2.)
(e) Inspect mounting bolts for corrosion. If corrosion is found, use new bolts when
installing caliper.
3. Brake Pad Removal
(a) Remove the inboard pad and spring from piston. Dislodge the outboard pad and
remove from caliper.
(b) Remove sleeves from mounting bolt holes and discard. Remove the four rubber
bushings from the grooves in each of the caliper ears and discard. (See Figure 3.)
4. Cleaning and inspection:
(a) Examine the piston area for fluid leaks by looking for excessive moisture around
boot area. Check dust boot for cracks, cuts or other damage that would affect its
ability to seal piston bore. If leaks are present or boot shows damage, the caliper
should be overhauled. See specific section.
(b) If no defects are found, wipe clean the inside of the caliper including the four ears
where bushings are to be installed. Wipe the outside surface of the dust boot so that
when piston is pressed to bottom of bore, boot will fold back without coming out of
groove.
Figure 2

Chapter 3: Overhaul Sept. 1995 Section 3-5 p. 3
Figure 3: