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.