1991 MITSUBISHI MONTERO service

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A/C C O M PR ESSO R O IL C HEC KIN G

1991 M it s u bis h i M onte ro
1991 GENERAL SERVICING
Compressor Refrigerant Oil Checking
ISOLATING COMPRESSOR
NOTE: Only compressors with stem-type service valves can be
isolated.
1) Connect service gauge set to the compressor service valves
and open compressor valves slightly (turn in clockwise). Start engine
and operate air conditioning. Slowly turn compressor suction valve
clockwise toward closed (front-seated) position.
2) When suction pressure is reduced to zero or less, turn off
engine and compressor and quickly turn suction valve stem in to full
front-seated position. Suction pressure should be slightly above zero.
Turn discharge valve into front-seated position.
3) To check oil level, slowly open compressor crankcase plug
to relieve any remaining pressure. After oil level is corrected, cap
service gauge ports on both valves. Back-seat suction service valve to
allow refrigerant to enter compressor. Open discharge valve halfway.
4) Loosen discharge service valve cap, allowing refrigerant
pressure to force air out of compressor. Back-seat service valve and
tighten cap. Compressor is now ready for operation.
REFRIGERANT OIL
Only new, pure, moisture-free refrigerant oil should be used
in the air conditioning system. This oil is highly refined and
dehydrated to a point where moisture content is less than 10 parts per
million. The oil container must be tightly closed at all times when
not in use, or moisture will be absorbed into the refrigerant oil from
the air.
SERVICING PRECAUTIONS
NOTE: Recent findings by the EPA indicate that refrigerant is
harmful to the earth's protective Ozone layer. When
discharging refrigerant, DO NOT allow refrigerant to enter
the atmosphere. If available, use refrigerant
recovery/recycle systems when discharging system. Always
follow manufacturer's instructions.
DISCHARGING SYSTEM PRECAUTIONS
If compressor has stem-type service valves, it can be
isolated and removed without discharging entire system. See ISOLATING
COMPRESSOR at the beginning of this article. Otherwise, discharge
system completely before loosening any fittings.
DISCONNECTING LINES & FITTINGS TEST
After system is discharged, carefully clean area around all
fittings to be opened. Always use 2 wrenches when tightening or
loosening fittings to avoid twisting or distorting lines. Cap or plug
all openings as soon as lines are removed. DO NOT remove caps until
immediately before connections are made. This will keep entry of air

and moisture to a minimum.
CONNECTING LINES AND FITTINGS
A new gasket or "O" ring should be used in all instances when
connecting lines or fittings. Dip "O" ring in new refrigerant oil and
ensure it is not twisted during installation. Always use 2 wrenches to
prevent damage to lines and fittings.
PLACING SYSTEM IN OPERATION
After component service or replacement has been completed and
all connections have been made, evacuate system thoroughly with a
vacuum pump. Charge system with proper amount of refrigerant and
perform a leak test. See REFRIGERANT OIL & R-12 SPECIFICATIONS chart
in this section for system capacities. Be sure to check all fittings
that have been opened. After system has been leak tested, make a
system performance check.
NOTE: Air conditioning systems will not normally need addition of
refrigerant oil unless definite oil loss has occurred due to
ruptured lines, leaking compressor seals, compressor
overhaul or component replacement.
ATSUGI ROTARY VANE DRAIN & REFILL
1) Before checking and adjusting oil level, operate
compressor at engine idling speed, with controls set for maximum
cooling and high blower speed, for 20 to 30 minutes to return oil to
compressor.
2) Stop engine, discharge refrigerant and remove compressor
from vehicle. See SERVICING PRECAUTIONS at beginning of article. Drain
compressor oil from compressor discharge port and measure the amount.
Oil is sometimes hard to drain when compressor is cool. Remove oil
while compressor is warm.
3) If the amount drained is less than 3 ounces, conduct leak
tests at system connections, and if necessary, repair or replace
faulty parts. Check purity of oil and adjust oil level as follows.
4) If amount drained was above 3 ounces, oil level is right.
Pour in same amount as was drained. If amount drained was below 3
ounces, pour in 3 ounces of new refrigerant oil.
BOSCH 6-CYL DRAIN & REFILL
1) Before checking and adjusting oil level, operate
compressor at engine idling speed, with controls set for maximum
cooling and high blower speed, for 20 to 30 minutes to return oil to
compressor.
2) Stop engine and discharge refrigerant. Remove refrigerant
oil level inspection plug on side of compressor. Oil should be at
lower lip of threaded hole. Add necessary new refrigerant oil (if
low). Replace inspection plug and tighten to 10-12 ft. lbs. (14-16 N.
m).
CALSONIC V5 5-CYLINDER
1) Before checking and adjusting oil level, operate
compressor at 1000-1500 engine RPM, and set controls at maximum
cooling and blowing speed for 20-30 minutes to return oil to

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A/C C O M PR ESSO R S ER VIC IN G

1991 M it s u bis h i M onte ro
1991 GENERAL SERVICING
Compressor Service
* PLEASE READ THIS FIRST *
CAUTION: When discharging air conditioning system, use only approved
refrigerant recovery/recycling equipment. Make every attempt
to avoid discharging refrigerant into the atmosphere.
ISOLATING COMPRESSOR
NOTE: Only compressors with stem-type service valves can be
isolated.
1) Connect service gauge set to the compressor service valves
and open compressor valves slightly (turn in clockwise). Start engine
and operate air conditioning. Slowly turn compressor suction valve
clockwise toward closed (front-seated) position.
2) When suction pressure is reduced to zero or less, turn off
engine and compressor and quickly turn suction valve stem in to full
front-seated position. Suction pressure should be slightly above zero.
Turn discharge valve into front-seated position.
3) To check oil level, slowly open compressor crankcase plug
to relieve any remaining pressure. After oil level is corrected, cap
service gauge ports on both valves. Back-seat suction service valve to
allow refrigerant to enter compressor. Open discharge valve halfway.
4) Loosen discharge service valve cap, allowing refrigerant
pressure to force air out of compressor. Back-seat service valve and
tighten cap. Compressor is now ready for operation.
REFRIGERANT OIL
Only new, pure, moisture-free refrigerant oil should be used
in the air conditioning system. This oil is highly refined and
dehydrated to a point where moisture content is less than 10 parts per
million. The oil container must be tightly closed at all times when
not in use, or moisture will be absorbed into the refrigerant oil from
the air.
DISCHARGING SYSTEM PRECAUTIONS
CAUTION: When discharging air conditioning system, use only approved
refrigerant recovery/recycling equipment. Make every attempt
to avoid discharging refrigerant into the atmosphere.
If compressor has stem-type service valves, it can be
isolated and removed without discharging entire system. Otherwise,
discharge system completely using approved refrigerant
recovery/recycling equipment before loosening any fittings.
DISCONNECTING LINES & FITTINGS TEST
After system is discharged, carefully clean area around all
fittings to be opened. Always use 2 wrenches when tightening or
loosening fittings to avoid twisting or distorting lines. Cap or plug
all openings as soon as lines are removed. Do not remove caps until

immediately before connections are made. This will keep entry of air
and moisture to a minimum.
CONNECTING LINES AND FITTINGS
A new gasket or "O" ring should be used in all instances when
connecting lines or fittings. Dip "O" ring in new refrigerant oil and
ensure it is not twisted during installation. Always use 2 wrenches to
prevent damage to lines and fittings.
PLACING SYSTEM IN OPERATION
After component service or replacement has been completed and
all connections have been made, evacuate system thoroughly with a
vacuum pump. Charge system with proper amount of refrigerant and
perform a leak test. See REFRIGERANT OIL & R-12 SPECIFICATIONS chart
in this section for system capacities. Be sure to check all fittings
that have been opened. After system has been leak tested, make a
system performance check.
NOTE: Air conditioning systems will not normally need addition of
refrigerant oil unless definite oil loss has occurred due to
ruptured lines, leaking compressor seals, compressor
overhaul or component replacement.
ATSUGI ROTARY VANE CLUTCH R & I
Removal
When replacing compressor clutch, be careful not to scratch
shaft or bend pulley. When removing center bolt, hold clutch disc with
Clutch Holder (KV99231010). Using Hub Puller (KV998VR001 &
KV99231010), remove clutch disc. When removing pulley, remove lock nut
with Hub Socket (KV99235160).
Installation
Wipe oil off clutch surface. Adjust disc pulley clearance to
.012-.024" (.3-.6 mm). Tighten center bolt to 80-104 INCH lbs. (9.1-
11.8 N.m). Tighten clutch lock nut to 22-29 ft. lbs. (29-39 N.m). See\
Fig. 1 .
Fig. 1: Atsugi Rotary Vane Compressor
Courtesy of Nissan Motor Co., U.S.A.
BOSCH 6-CYL CLUTCH R & I

cover at low pressure side of compressor. Connect Pressurizer
(KV994C1552) to can of R-12 refrigerant. Wrap a rag around compressor
shaft. Apply pressure of 28-71 psi (2-5 kg/cm
) at low pressure
(suction) service valve of compressor. Catch shaft seal seat in rag.
See Fig. 11 .
NOTE: If shaft seal cannot be pulled out, reset to its original
position, and pressurize again.
4) Insert shaft seal Remover/Installer (KV994C1143) through
the open end of front cover. Depress carbon seal and hook tool at case
projection of shaft seal. Slowly pull out to remove shaft seal. See
Fig. 11 .
Fig. 10: Hitachi 6-Cylinder Compressor Shaft Seal Seat Removal
Courtesy of Nissan Motor Co., U.S.A.

Removal
1) Remove A/C compressor. Remove pressure plate shaft bolt
using socket wrench and Clutch Stopper (07112-76060). Install Clutch
Remover (07112-66040) on pressure plate. Using clutch stopper and
socket wrench, rotate clutch remover to remove pressure plate.
2) Remove shims from pressure plate. Remove snap ring from
compressor. Tap rotor off shaft with plastic hammer. Disconnect stator
wire from housing. Remove snap ring from inside stator. Remove stator.
See Fig. 12 .
CAUTION: DO NOT damage pulley when tapping on rotor.
Installation
To install, reverse removal procedure. Ensure snap rings are
installed with beveled side up. tighten shaft bolt to 10 ft. lbs.
(14 N.m). Ensure clutch clearance is .014-.026" (.36-66 mm). adjust
clearance by adding or subtracting shims as necessary.
NIPPONDENSO 6 & 10-CYL SHAFT SEAL R & I
NOTE: Check compressor refrigerant oil level when replacing seals.
See COMPRESSOR OIL CHECKING article in the AIR CONDITIONING &
HEAT section.
Removal
1) Hold clutch hub stationary and remove center nut. Screw
remover into center of hub. Turn center bolt to remove pressure plate.
2) Remove shims from shaft. Remove snap ring from inside of
pulley. Tap pulley off of shaft with plastic mallet. Be careful not to
distort pulley while removing.
3) Disconnect clutch coil wires from compressor housing.
remove snap ring inside coil and lift coil off compressor. Pry dust
seal out from around compressor shaft (if equipped).
4) Place shaft key remover on shaft and turn to remove key.
Remove drain plug (if equipped). Remove service valves-to-compressor
body bolts. Remove valves. Discard "O" rings. Drain oil out of
compressor.
5) Remove 6 through bolts from front head of compressor and
discard washers. Tap head loose from compressor; be careful not to
scratch sealing surfaces. remove snap ring (if equipped) from front
housing. Press seal plate out. Remove seal from shaft. See Fig. 14.
Installation
1) Lubricate shaft seal with clean refrigerant oil and place
on compressor shaft. Lubricate seal plate and "O" ring (if equipped)
and install in front housing. Install snap ring (if equipped).
2) Place front housing on compressor body. Install through
bolts with new washers. Tighten bolts evenly and alternately to
18 ft. lbs. (24 N.m). Install shaft key using installer and plastic
mallet. Insert dust seal into front of compressor.
3) Install drain plug with new gasket. Add correct amount of
refrigerant oil to compressor. If service valves were removed, coat
new "O" rings with refrigerant oil and install service valves.
4) Place clutch coil on compressor and install snap ring.
Install shims on shaft to adjust pressure plate-to-rotor clearance to
.016-.028" (.41-.71 mm). Tighten shaft nut to 12 ft. lbs. (16 N.m).

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* A /C -H EA TE R S YSTE M U NIF O RM IN SPEC TIO N G UID ELIN ES *

1 991 M it s u bis h i M onte ro
GENERAL INFORMATION
A/C-Heater System Motorist Assurance Program
Standards For Automotive Repair
All Makes and Models
INTRODUCTION TO MOTORIST ASSURANCE PROGRAM (MAP)
CONTENTS
Motorist Assurance Program (MAP)
OVERVIEW
OVERVIEW OF SERVICE REQUIREMENTS & SUGGESTIONS
Heating, Ventilation and Air Conditioning
ACCUMULATORS
ACTUATORS (ELECTRICAL)
ACTUATORS (VACUUM)
AIR CONDITIONING FITTINGS
AIR CONDITIONING HOSES
AIR CONDITIONING METAL LINES, HOSES AND FITTING ASSEMBLIES
AIR CONTROL DOORS
AIR DAMS (EXTERNAL)
AIR DISTRIBUTION SYSTEM
BELTS
BLEND DOORS
BLOWER FANS (BLOWER WHEEL OR SQUIRREL CAGE)
BLOWER MOTORS
BLOWER RESISTORS
BLOWER SWITCHES
CABIN AIR FILTERS
CIRCUIT BREAKERS
COMPRESSOR CLUTCH ASSEMBLIES
COMPRESSORS
CONDENSER AIR SEALS
CONDENSER FAN MOTORS
CONDENSERS
CONNECTORS
CONTROL CABLES
CONTROL HEADS (FUNCTION SELECTORS)
CONTROL LINKAGES
CONTROL MODULES
COOLANT
COOLING FAN BLADES
COOLING FAN CLUTCHES
COOLING FAN MOTORS
EVAPORATOR DRAIN TUBES
EVAPORATOR PRESSURE REGULATORS (EPRS)
EVAPORATORS
EXPANSION VALVES
FUNCTION SELECTORS
FUSES, FUSIBLE LINKS AND CIRCUIT BREAKERS
FUSIBLE LINKS
GASKETS
HEATER CASES
HEATER CONTROL VALVES
HEATER CORES

HEATER HOSES
HIGH PRESSURE RELIEF VALVES (HPRV)
IDLERS
IN-LINE FILTERS
METAL FITTINGS
METAL LINES
MIX AND AIR CONTROL DOORS (BLEND DOORS)
O-RINGS
ORIFICE TUBES
PILOT-OPERATED ABSOLUTES (POAS)
PLENUMS
PRESSURE CONTROL VALVES
PRESSURE SENSORS
PULLEYS
RADIATORS
RECEIVER-DRIERS
REFRIGERANT
REFRIGERANT OIL
RELAYS
SEALS
SERVICE PORTS
SPRING LOCK COUPLINGS
SUCTION THROTTLING VALVES (STVS)
SWITCHES (ELECTRICAL)
TENSIONERS
THERMISTORS AND PRESSURE SENSORS
THERMOSTATS AND HOUSINGS
VACUUM HOSES AND TUBES
VACUUM RESERVOIRS
VACUUM TUBES
VALVES IN RECEIVER (VIRS)
WATER PUMPS (ELECTRIC AUXILIARY)
WIRING HARNESSES AND CONNECTORS
MOTORIST ASSURANCE PROGRAM (MAP)
OVERVIEW
The Motorist Assurance Program is the consumer outreach
effort of the Automotive Maintenance and Repair Association, Inc.
(AMRA). Participation in the Motorist Assurance Program is drawn from
retailers, suppliers, independent repair facilities, vehicle
manufacturers and industry associations.
Our organization's mission is to strengthen the relationship
between the consumer and the auto repair industry. We produce
materials that give motorists the information and encouragement to
take greater responsibility for their vehicles-through proper,
manufacturer-recommended, maintenance. We encourage participating
service and repair shops (including franchisees and dealers) to adopt
(1) a Pledge of Assurance to their Customers and (2) the Motorist
Assurance Program Standards of Service. All participating service
providers have agreed to subscribe to this Pledge and to adhere to the
promulgated Standards of Service demonstrating to their customers that
they are serious about customer satisfaction.
These Standards of Service require that an inspection of the
vehicle's (problem) system be made and the results communicated to the\
customer according to industry standards. Given that the industry did
not have such standards, the Motorist Assurance Program successfully
promulgated industry inspection communication standards in 1994-95 for
the following systems: Exhaust, Brakes, ABS, Steering and Suspension,
Engine Maintenance and Performance, HVAC, and Electrical Systems.
Further, revisions to all of these inspection communication standards