1991 MITSUBISHI MONTERO lock

(1) - This condition may be normal on some vehicles equipped with
anti-lock brakes.
( 2) - Refer to OEM procedures for adjusting low fluid level.
Inspect for brake hydraulic system leaks and friction
material wear.
( 3) - This condition may indicate contaminated brake fluid.
See BRAKE FLUID .









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MODULATORS
See HYDRAULIC MODULATORS .
MOTORS
See ELECTRICAL PUMPS AND MOTORS .
PARKING BRAKE SWITCHES
See SWITCHES.
PARKING BRAKE SYSTEMS
NOTE: The parking brake is an integral part of the brake
system. It is important that the parking brake function
properly when brake service is performed.
PARKING BRAKE SYSTEM INSPECTION









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Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Cable improperly
adjusted ............... B ....... Require cable adjustment.
Cable or individual
wires in the cable
are broken ............. A .... Require replacement of cable
assembly.
Cable sticking .......... A ...... Require cable lubrication.
Cable stuck inside conduit
and cannot be lubricated
so that parking brake
functions properly ..... A .... Require replacement of cable
assembly.
Inoperative ( 1) ......... A .......... Require replacement of
inoperative parts.
Parking brake
parts bent ............. B ... Require repair or replacement
of bent parts.
Parking brake
parts broken ........... A ... Require replacement of broken
parts.
Parking brake parts

Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
(1) - Inoperative includes intermittent operation or out of OEM
specification.
( 2) - Determine cause and correct prior to repair or
replacement of part.









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ROTORS
Determine the need to recondition based upon individual rotor
conditions that follow. Friction material replacement does not require
rotor reconditioning unless other justifications exist. DO NOT
recondition new rotors unless they are being pressed or bolted onto an
existing hub. It is not necessary to replace rotors in axle sets.
However, when replacing or reconditioning a rotor due to the
conditions that follow, you may suggest reconditioning of the other
rotor on the same axle to eliminate uneven braking behavior.
Determine the need to replace based upon the individual rotor
conditions that follow. Reconditioning is defined as machining and
block sanding, or block sanding only. Block sanding is defined as
using 120-150 grit sandpaper with moderate to heavy force for 60
seconds per side. Always wash rotors after servicing or before
installing.
ROTOR INSPECTION









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Condition Code Procedure
Corrosion affecting
structural integrity ... A ........ ( 1) Require replacement.
Cracked ................. B ............ Require replacement.
Hard spots .............. 2 ....... Suggest reconditioning or
replacement of rotor according
to OEM specifications.
Lateral runout (wobble)
exceeds OEM
specifications ......... B ............ Require re-indexing,
reconditioning, or replacement
according to specifications.
Measured thickness is less
than OEM discard
specifications ......... B ............ Require replacement.
Rotor thickness is less
than OEM "machine to"
specifications but thicker
than "discard at"
specifications, and the
rotor does not require
reconditioning ......... 1 ........ ( 2) Suggest replacement.
Rotor thickness will be
less than OEM "machine to"
specifications after
required

BRAK E S YSTE M

1991 M it s u bis h i M onte ro
1991 BRAKES
Disc & Drum
Chrysler Motors: Ram-50;
Mitsubishi: Montero, Pickup
DESCRIPTION
Brake system consists of a master cylinder, vacuum power
brake unit, proportioning valve and self-adjusting assembly. Pickup
and Ram-50 models have a Load-Sensing Proportioning Valve (LSPV). All
models are equipped with front disc brakes and rear drum brakes.
Parking brake assembly activates rear brakes.
BLEEDING BRAKE SYSTEM
BLEEDING PROCEDURES
Montero
Bleed brake system in following order: right rear, right
front and left front (one circuit handles both rear brakes).
Pickup & Ram-50
Bleed brake system in following order: right rear, left rear,
LSPV, right front and left front.
ADJUSTMENTS
BRAKE PEDAL HEIGHT & FREE PLAY
1) Separate connector from stoplight switch, and loosen lock
nut. Position switch so it does not contact brake pedal arm. Adjust
brake pedal height by rotating master cylinder push rod (yoke, if
equipped) until distance from top of brake pedal to floor board is
correct. See BRAKE PEDAL SPECIFICATIONS table.
2) DO NOT depress push rod. Tighten lock nut, and ensure
brake pedal height is within specification. Start engine to evacuate
brake booster chamber. Stop engine, and apply brake several times to
remove vacuum from brake booster.
3) Using hand pressure, depress brake pedal to measure free
play before resistance is felt. If distance is incorrect, bleed the
brake hydraulic system, and check for misadjusted brakes. Refer to the
BRAKE PEDAL SPECIFICATIONS table.
BRAKE PEDAL SPECIFICATIONS TABLE









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Free Play Pedal Height
Application In. (mm) In. (mm)
Montero ............ .12-.31 (3-8) ... 7.5-7.7 (191-196)
Pickup & Ram-50 .... .12-.31 (3-8) ........... 6.5 (166)









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LOAD-SENSING PROPORTIONING VALVE (LSPV) (Pickup & Ram-50)
Park vehicle on level surface. Remove all luggage and
passengers. Ensure lever is not against stopper bolt. Check spring

brake pedal to center shoes, and check pedal travel. Rotate brake drum
to verify free movement.
STOPLIGHT SWITCH
Loosen lock nut, and adjust switch-to-pedal arm clearance to
.02-.04" (.5-1.0 mm). Tighten lock nut. DO NOT depress master cylinder
push rod during stoplight switch adjustment.
TESTING
POWER BRAKE UNIT
Check Valve Inspection
Remove vacuum hose from power brake unit. Remove check valve
from hose (if possible). Using a vacuum pump, ensure airflow is in
direction of intake manifold only.
System Check
1) Run engine for 2 minutes, and shut it off. Depress brake
pedal several times with normal pressure. If pedal height gradually
becomes higher with successive applications, power brake unit is okay.
If pedal height remains steady, power brake unit is faulty.
2) With engine stopped, depress brake pedal repeatedly until
it's height no longer falls. Hold brake pedal down, and start engine.
If pedal moves downward slightly, power brake unit is okay. If pedal
height does not change, power brake unit is faulty.
3) With engine running, press and hold brake pedal and shut
off engine. Hold brake pedal for 30 seconds. Brake pedal height should
not change. If pedal height falls, power brake unit is faulty.
LOAD-SENSING PROPORTIONING VALVE (LSPV) (PICKUP & RAM-50)
1) Before diagnosing Load-Sensing Proportioning Valve (LSPV)\
,
ensure all other brake components are operating properly. When all
other brake system components are determined to be okay, perform LSPV
test beginning with next step.
2) Ensure unladen vehicle is on level ground. Ensure lever is
not contacting stopper bolt. See Fig. 1.
3) When lever is pushed toward valve, distance from LSPV
lever hole and support hole must be 6.97-7.09 in. (177-180 mm). If
measured distance is not within specification, loosen support bolt.
Adjust support until measured distance is within specification.
4) After measured distance is within specification, connect
pressure gauges to input and output ports of LSPV. See Fig. 4. Bleed
brake system. See BLEEDING BRAKE SYSTEM .
Fig. 4: Connecting Pressure Gauges to LSPV (Pickup & Ram-50)
Courtesy of Mitsubishi Motor Sales of America.

Inlet Pressure Outlet Pressure
Application psi (kg/cm) psi (kg/cm)
2.6L
Test 1 ............ 853 (59) ......... 473-526 (33-37)
Test 2 ........... 1280 (88) ......... 672-757 (46-52)
3.0L
2-Door Model
Test 1 .......... 853 (59) ......... 473-526 (33-37)
Test 2 ......... 1565 (108) ........ 768-865 (54-60)
4-Door Model
Test 1 .......... 597 (41) ......... 569-626 (39-43)
Test 2 ......... 1377 (95) ......... 843-928 (58-64)
( 1) - Maximum side-to-side pressure differential
is 57 psi (4kg/cm
).








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REMOVAL & INSTALLATION
FRONT BRAKE PADS
CAUTION: DO NOT remove or contaminate special grease coating on lock
pins.
Removal
1) Raise and support vehicle. Remove front wheel(s). Remove
lower lock pin or sleeve bolt. See Fig. 6. Lift caliper body upward.
2) Support caliper using wire. Remove shim(s), shim holder
(if equipped), anti-squeak shim and pad assembly from support
mounting. Remove pad clips.
Installation
If installing new pads, compress piston to bottom of bore.
Install retaining clips, pad assembly, shim(s), shim holder (if
equipped) and anti-squeak shim onto support mounting.
Fig. 6: Exploded View of Front Disc Brake Assembly (Typical)
Courtesy of Chrysler Motors.
FRONT BRAKE CALIPER

Removal
1) Raise and support vehicle. Remove front wheel(s). Separat\
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rubber flex hose from hydraulic line at brake hose mount, located on
strut housing. Secure end of hydraulic line to prevent spillage of
brake fluid.
2) Remove hose clip from brake hose mount. Disconnect brake
hose from caliper. Remove upper and lower caliper-to-steering knuckle
bolts. Lift caliper body upward. Remove caliper.
Installation
To install, reverse removal procedure. Tighten bolts to
specification. See the TORQUE SPECIFICATIONS table. Bleed brake
system. See BLEEDING BRAKE SYSTEM .
FRONT BRAKE ROTOR
Removal (Montero, Pickup 4WD & Ram-50 4WD)
Raise and support vehicle. Remove and support brake calipers.
Place hub in free-wheeling position. Remove drive hub cover using an
oil filter wrench and protective cloth. Remove snap ring, shim and
free-wheeling hub from drive axle. See Fig. 7. Remove lock washer.
Remove lock nut using Lock Nut Wrench (MB990954). Remove front hub
assembly.
Fig. 7: Exploded View of Front Brake Assembly (4WD)
Courtesy of Mitsubishi Motor Sales of America.
Installation
1) Install front hub assembly. Install and tighten lock nut
to 94-145 ft. lbs. (127-197 N.m), and then loosen and retighten to 18
ft. lbs. (24 N.m). Loosen lock nut 30-40 degrees. Reverse removal
procedure for remaining components. After installation is complete,
check drive axle end play. Adjust end play if not .002" (.05 mm) or
less. Rotate drive axle forward and rearward until maximum end play is
obtained.
2) If adjusting axle shaft end play, use proper shim to
obtain desired end play. Shim is located behind snap ring on end of
drive axle. Install shim, and recheck axle end play.
Removal (Pickup 2WD & Ram-50 2WD)
Raise and support vehicle. Remove front caliper. Remove hub
(dust) cap, cotter pin and nut. Remove washer and outer wheel bearing.\
Remove front hub assembly. Remove bolts attaching rotor to front hub,
and separate assemblies.

POWER BRAKE UNIT CHECK VALVE
NOTE: To test check valve before removal, stop engine, and apply
service brake to ensure air flows only toward intake
manifold.
Removal & Installation
Loosen hose clamps, and remove check valve. Before
installation, coat both ends of check valve with sealant, and install
valve with arrow (identification mark) pointing toward intake
manifold. Install check valve clamp, and secure hose clamps.
POWER BRAKE UNIT
Removal
Remove brake master cylinder. Disconnect vacuum hose from
power brake unit. Disconnect clevis pin attaching brake pedal to power
brake unit push rod. From inside vehicle, remove 4 nuts attaching
power brake unit to firewall. Remove power brake unit.
Installation
To install, reverse removal procedure. Install master
cylinder. Bleed brake system if necessary.
REAR AXLE BEARINGS & OIL SEAL
Removal (Montero)
1) With drum removed, disconnect brake line from wheel
cylinder. Disconnect bearing case from axle housing end. Remove brake
backing plate, bearing case and axle shaft as an assembly. If axle
shaft binds, use slide hammer with puller to remove.
2) Remove "O" ring and shims for preloading wheel bearing (if\
equipped). Retain shims for reassembly. To remove oil seal, use slide
hammer and hook.
3) To remove wheel bearing, straighten lock washer tabs. See
Fig. 9 . Remove lock nut using spanner wrench. Remove lock washer.
Install lock nut 3 turns on axle shaft. Install Puller (MB990787-01)
to remove axle shaft from bearing case. Rotate nuts with equal force
to remove axle shaft. Remove bearing outer race using a hammer and
drift.
Fig. 9: Removing Rear Axle Bearing (Montero)
Courtesy of Mitsubishi Motor Sales of America.
Installation
1) Apply Multipurpose Grease (SAE J310) to oil seal. Install\

oil seal using seal driver. Apply grease to outside circumference of
bearing outer race. Apply grease to lip of oil seal and to roller
surfaces of bearing inner race.
2) Press bearing onto axle shaft. Install rear brake assembly
and bearing case. Pack bearing case and axle threads with grease.
Install lock washer (tab aligned with axle slot) and lock nut (chamfe\
r
toward lock washer). Tighten lock nut to 130-159 ft. lbs. (176-216 N.
m).
3) Bend tabs on lock washer into slots of lock nut. Apply
grease to oil seal area of rear axle housing. Adjust clearance between
bearing case and rear axle by inserting .04" (1.0 mm) shim and "O"
ring into left rear axle housing.
4) Apply semi-drying sealant to mating surface of bearing
case. Install left axle shaft into rear housing. Tighten nuts
diagonally to 36-43 ft. lbs. (49-58 N.m).
5) Install right axle shaft without shims and "O" ring.
Temporarily tighten to about 53 INCH lbs. (6 N.m). Using a feeler
gauge, measure clearance between bearing case and rear axle housing.
6) Remove right axle shaft. Install shims to equal bearing
case-to-axle housing clearance plus .002-.008" (.05-.20 mm). Install
"O" ring to right rear axle housing. Apply sealant to mating surfaces
of bearing case and shim. See Fig. 10.
7) Install axle into housing, tightening nuts diagonally to
36-43 ft. lbs. (50-58 N.m). Check axle shaft for .002-.008" (.05-.20
mm) end play using dial indicator.
Fig. 10: Applying Sealant (Montero, Pickup & Ram-50)
Courtesy of Mitsubishi Motor Sales of America.
Removal (Pickup & Ram-50)
1) With drum removed, disconnect brake line from wheel