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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
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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
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A/C S YSTE M P R EC AU TIO NS
1991 M it s u bis h i M onte ro
AIR CONDITIONING & HEAT
A/C System Precautions
* 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.
BEFORE OPENING THE SYSTEM
Before disconnecting any lines or fittings, the system must
be completely discharged using approved refrigerant recovery/recycling
equipment.
DISCHARGING A/C SYSTEM
NOTE: Recent findings by the EPA indicate that R-11, R-12 and R-113
are harmful to the Earths' protective Ozone layer. Make every
attempt possible, to avoid discharging R-11, R-12 or R-113
into the atmosphere.
1) Remove service valve caps and install gauges. For high
side gauge hose, Adapter (D81L-19703-A) must be used to connect to
high side service valve.
2) Place open end of center hose in garage exhaust outlet or
in a well ventilated area. Slightly open low side gauge valve and let
refrigerant escape slowly without loosing refrigerant oil.
3) When system is nearly discharged, using approved
refrigerant recovery/recycling equipment, open high side gauge valve
to release any pressure trapped in compressor. Close valves
immediately after discharging to prevent entry of moisture.
DISCONNECTING LINES & FITTINGS
1) After system is discharged, using approved refrigerant
recovery/recycling equipment, carefully clean entire area around
coupling nut to prevent dirt entering system. Always use two wrenches
to avoid twisting or distorting lines and fittings (hold fitting with
one wrench while loosening coupling nut with second wrench).
2) Cap or plug all LINES and FITTINGS immediately to prevent
entry of air and moisture into system. Do not remove these caps until
connections are being made.
COMPONENT REPLACEMENT
When components are replaced, system oil level must be
adjusted. Add refrigeration oil to replacement component. See
Compressor oil Check article, as well as, Component Oil Replacement
Quantities" chart under "A/C SYSTEM SPECS" article in this section.
USING R-12 REFRIGERANT - SAFETY PRECAUTIONS
1) Always work in a well-ventilated, clean area. Refrigerant
(R-12) is heavier than oxygen, and will displace oxygen in a confined
area. Always wear eye protection when working around air conditioning
systems and R-12. The system's high pressure can cause severe injury
to eyes and skin if a hose were to burst. R-12 evaporates quickly
when exposed to atmosphere, freezing anything it contacts.
2) Use care when handling refrigerant containers. DO NOT drop
or strike containers or expose refrigerant containers to excessive
heat. Containers must never be heated more than 125
F (52 C). Never
expose R-12 directly to open flame.
CAUTION: When R-12 is exposed to an open flame, drawn into a running
engine, or detected with a Halide (propane) leak tester,
poisonous phosgene gas is formed. Keep work areas ventilated
and avoid running engines near work area.
USING INDIVIDUAL R-12 CANS
Disposable refrigerant cans (referred to as one pound cans)
have a flat type seal or a screw type seal, and proper can tap must be
used for each type. Be sure sealing gasket on can tap is in good
condition. A proper safety can tap will prevent refrigerant from
flowing back into open can, as tap has a one-way flow control.
NOTE: Recent findings by the EPA indicate that refrigerant is
harmful to the Earth's protective Ozone layer. When
discharging refrigerant avoid allowing refrigerant to enter
the atmosphere. Refrigerant recovery system should be used
when discharging the system.
MULTI-CAN DISPENSING VALVES
A multi-can dispensing valve allows attachment of several
cans of refrigerant, and is a good substitute when a bulk container is
not available. Cans are installed onto each leg of multi-can
dispensing valve in the same manner as the individual cans, and each
leg has its own can tap.
CAN TAP INSTALLATION FLAT TYPE SEAL CANS
On cam-lock or one-piece can taps, first turn the handle
outward to the fully open position. Securely engage locking lugs over
the can flange, and lock them in place by turning cam lock or locking
nut. Screw tap assembly into adapter so sealing gasket is fully seated
against the can top. Turn tap inward to pierce the can and close the
tap. DO NOT open tap until ready to purge the service hose or dispense
refrigerant into the system.
On 2-piece can taps, be certain tap handle is turned fully
inward to the closed position. Check that locking base is turned to
its outer limit. Securely engage locking lugs over the can flange.
Turn entire tap assembly (without disturbing the closed setting)
downward into the locking base to pierce the can. DO NOT open tap
until ready to dispense into system.
SCREW TYPE SEAL CANS
Ensure can tap is fully closed. Screw refrigerant can into
can tap fitting until tight. This will pierce the can. Connect tap to
center hose on manifold gauge set. DO NOT open tap until ready to
dispense R-12 into system.
WARNING: DO NOT open high side hand valve while air conditioning
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A ... Require repair or replacement
of hardware.
Binding, affecting
performance ............ A .. Require repair or replacement.
Binding, not affecting
performance ............ 2 .. Suggest repair or replacement.
Broken .................. A .. Require repair or replacement.
Burned, affecting
performance ............ A ........... (1) Require repair or
replacement.
Burned, not affecting
performance ............ 2 ........... ( 1) Suggest repair or
replacement.
Cracked, affecting
performance ............ A .. Require repair or replacement.
Cracked, not affecting
performance ............ 1 .. Suggest repair or replacement.
Float saturated ......... A ............ Require replacement.
Leaking ................. A .. Require repair or replacement.
Malfunctioning .......... A ........... ( 2) Require repair or
replacement.
Melted, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Melted, not affecting
performance ............ 2 ........... ( 1) Suggest repair or
replacement.
Missing ................. C ............ Require replacement.
Out of adjustment ....... B .. Require repair or replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
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.
Won't return ............ A .. Require repair or replacement.
Worn .................... 1 ............ Suggest replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Includes inoperative, intermittent operation, or failure to
perform all functions.
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TIRES
Consult the vehicle owner's manual or vehicle placard for
correct size, speed ratings, and inflation pressure of the original
tires.
TIRE INSPECTION