Bracket cracked, not
affecting performance .. 1 .. Suggest repair or replacement.
Bracket holes elongated,
affecting performance .. A .. Require repair or replacement.
Bracket holes elongated,
not affecting
performance ............ .. ........ No service suggested or
required.
Bracket loose, affecting
performance ............ A .. Require repair or replacement.
Bracket loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Bracket missing ......... C ............ Require replacement.
Connection damaged ...... B .. Require repair or replacement.
Contaminated, affecting
performance ............ A ............ Require replacement.
Corroded internally ..... 1 ............ Suggest replacement.
Dessicant bag
deteriorated ........... A ........ (1) Require replacement.
Further inspection required.
Dessicant at the end of
its useful life
(saturated
with moisture) ......... 1 .. Suggest repair or replacement.
Filter screen torn ...... A .. Require replacement of screen.
Fitting damaged ......... B .. Require repair or replacement.
Fusible plug leaking .... A .... Require replacement of plug.
Inoperative ............. A ........... ( 2) Require repair or
replacement.
Leaking ................. A .. Require repair or replacement.
Pressure relief device
leaking ................ A . Require replacement of pressure
relief device.
Restricted .............. A .. Require repair or replacement.
Sight glass no longer
transparent ............ 2 ... Suggest replacement of drier.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
Tubing connection
leaking ................ A .. Require repair or replacement.
( 1) - Inspect system to determine effects of dessicant bag
deterioration.
( 2) - Inoperative includes intermittent operation or out of
OEM specification.
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WATER PUMPS (ELECTRIC AUXILIARY)
WATER PUMP (ELECTRIC AUXILIARY) 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.
A/C-HEATER SYSTEM
1998 Mitsubishi Montero
1998 AIR CONDITIONING & HEAT
Mitsubishi - A/C-Heater System
Montero
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article.
A/C SYSTEM SPECIFICATIONS
A/C SYSTEM SPECIFICATIONS TABLE \
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Application Specification
Compressor Type ............... Nippondenso 10PA15 10-Cyl.
Compressor Belt Deflection ( 1)
New .......................... 13/64-15/64" (5.1-6.0 mm)
Used ......................... 17/64-19/64" (6.6-7.5 mm)
Compressor Oil Capacity ..................... ( 2) 2.7 ozs.
Refrigerant (R-134a) Capacity ................. 21-23 ozs.
System Operating Pressures ( 4)
High Side ............... 149-213 psi (10.5-15.0 kg/cm
)
Low Side .................... 14-33 psi (1.0-2.3 kg/cm)
( 1) - With 22 lbs. (100 N.m) force applied midway on longest
span of belt.
( 2) - Use ND 8-OIL refrigerant oil.
( 3) - Use SUN PAG 56 refrigerant oil.
( 4) - With ambient temperature at about 80
F (27C). \
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DESCRIPTION
Slight variations exist among manual A/C-heater systems used.
On Montero, a Nippondenso 10-cylinder compressor is used. Cycling of
compressor clutch is controlled by an automatic A/C Control Unit
(ACCU).
Compressors will only operate within normal temperatures and
pressures set for each model. An electric condenser fan operates
whenever A/C system is operating. System components may vary depending
upon model. Systems may include an ACCU, fan switch, evaporator,
temperature sensor, dual-pressure switch, engine coolant temperature
switch, compressor, condenser, receiver-drier and various pipes and
hoses.
OPERATION
A/C CONTROL UNIT (ACCU)
ACCU controls cycling of compressor clutch based on
information received from air thermosensor and air inlet sensor, dual-
pressure switch, A/C switch and A/C engine coolant temperature switch.
ACCU is attached to top of evaporator housing.
ADJUSTMENTS
NOTE: For adjustment procedures, see HEATER SYSTEM article.
TROUBLE SHOOTING
NO COOLING
1) Ensure compressor clutch is operating. If compressor
clutch is operating, go to next step. If compressor clutch is not
operating, check fuses and A/C switch. Check dual-pressure switch.
Check air inlet sensor and air thermosensor. Check A/C compressor
relay. Check A/C compressor clutch coil. Check A/C control unit.
2) Ensure system is properly charged with correct amount of
refrigerant. Evacuate and charge system as necessary. Ensure receiver-
drier is not clogged. Check compressor belt for proper tension. Check
for clogged expansion valve. Check compressor operation. Repair or
replace components as necessary.
INSUFFICIENT AIRFLOW
Check for air leakage at air duct joint. Check for frost on
evaporator. Ensure blower motor is operating properly. Check for
obstructed air intake.
INSUFFICIENT COOLING
Ensure system is properly charged with correct amount of
refrigerant and free of air and moisture. Evacuate and charge system
as necessary. Ensure receiver-drier is not clogged. Ensure sufficient
airflow through condenser exists. Check compressor belt for proper
tension. Check compressor operation. Repair or replace compressor as
necessary. Check for clogged expansion valve. Replace expansion valve
as necessary. Check A/C compressor clutch coil.
INTERMITTENT COOL AIR
Check for air or moisture in system. Evacuate and charge
system as necessary. Check for expansion valve malfunction. Replace
expansion valve if necessary. Check compressor belt for proper
tension.
TESTING
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article.
NOTE: For testing procedures not covered in this article, see
HEATER SYSTEM article.
A/C SYSTEM PERFORMANCE
1) Park vehicle out of direct sunlight. Install A/C gauge
set. Start engine and allow it to idle at 1000 RPM. Turn A/C on. Set
A/C controls to recirculated air, panel (vent) mode and full cold
Fig. 6: Testing 4-Terminal Relay
Courtesy of Mitsubishi Motor Sales of America.
REMOVAL & INSTALLATION
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT
SYSTEM article.
NOTE: For removal and installation procedures not covered in this
article, see HEATER SYSTEM article.
A/C CONTROL UNIT (ACCU)
Removal & Installation
Lower glove box. Remove 2 clips on top of evaporator, and
remove ACCU. Disconnect wiring harness from ACCU. To install, reverse
removal procedure. See Fig. 7.
Fig. 7: Locating A/C Control Unit (ACCU)
Courtesy of Mitsubishi Motor Sales of America.
A/C SYSTEM GENERAL SERVICING
1998 Mitsubishi Montero
1998 AIR CONDITIONING & HEAT
Mitsubishi - A/C System General Servicing
Diamante, Eclipse, Galant, Mirage, Montero, Montero Sport &
3000GT
A/C COMPRESSOR APPLICATIONS
A/C COMPRESSOR APPLICATION TABLE \
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Application Compressor
Diamante ......................... Sanden MSC105CVS Scroll
Eclipse
2.0L Non-Turbo ............. Nippondenso 10PA17C 10-Cyl.
2.0L Turbo & 2.4L .............. Sanden MSC105CVS Scroll
Galant ............................ Sanden MSC90C12 Scroll
Mirage ............................... Sanden MSC90 Scroll
Montero ....................... Nippondenso 10PA15 10-Cyl.
Montero Sport ...................... Sanden MSC105C Scroll
3000GT .............................. Sanden MSC105 Scroll
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USING R-12 & R-134a REFRIGERANT
HANDLING/SAFETY PRECAUTIONS
1) Always work in a well-ventilated, clean area. Avoid
breathing refrigerant vapors. Exposure may irritate eyes, nose and
throat. Refrigerant is colorless and is invisible as a gas.
Refrigerant is heavier than oxygen and will displace oxygen in a
confined area.
2) A/C system high pressure can cause severe injury to eyes
and skin if a hose were to burst. Always wear eye protection, gloves
and other protective clothing when working around A/C system and
refrigerant.
3) Refrigerant evaporates quickly when exposed to atmosphere,
freezing anything it contacts. If liquid refrigerant contacts eyes or
skin (frostbite), DO NOT rub eyes or skin. Immediately flush affected
area with cool water for 15 minutes and consult a doctor or hospital.
4) Never use R-134a in combination with compressed air for
leak testing. Pressurized R-134a in the presence of oxygen (air
concentrations greater than 60 percent by volume) may form a
combustible mixture. DO NOT introduce compressed air into R-134a
containers (full or empty), A/C system components or service
equipment.
5) DO NOT expose A/C system components to high temperatures,
steam cleaning for example, as excessive heat will cause
refrigerant/system pressure to increase. Never expose refrigerant
directly to open flame. If refrigerant needs to be warmed, place
bottom of refrigerant tank in warm water. Water temperature MUST NOT
exceed 125
F (52C).
CAUTION: When R-134a is exposed to an open flame, drawn into engine,
or detected with a Halide (propane) leak tester, a poisonous
gas is formed. Keep work areas well ventilated.
6) Use care when handling refrigerant containers. DO NOT
drop, strike, puncture or incinerate containers. Use Department Of
Transportation (DOT) approved, DOT 4BW or DOT 4BA refrigerant
containers.
7) Never overfill refrigerant containers. The safe filling
level of a refrigerant container MUST NOT exceed 60 percent of the
container's gross weight rating. Store refrigerant containers at
temperature less than 125
F (52C).
8) R-134a refrigerant is sold and stored in 30- or 50-pound
Light Blue containers, while Freon (R-12) is stored in White colored
containers.
9) Refrigerant R-12 and R-134a must never be mixed, as they
and their desiccants and lubricants are not compatible. If
refrigerants are mixed, system cross-contamination or A/C system
component failure may occur. Always use separate servicing and
refrigerant recovery/recycling equipment.
10) Follow equipment manufacturer instructions of all service
equipment to be used. The Material Safety Data Sheet (MSDS), provided
by refrigerant manufacturer/suppliers, contains valuable information
regarding the safe handling of refrigerants.
11) Before connecting refrigerant lines always lubricate "O"
rings using appropriate refrigerant oil.
12) Always plug or cap A/C system refrigerant lines and
component connections as soon as possible to protect components from
moisture and/or dust. DO NOT remove plugs or caps until ready to
install component.
13) Always use a back-up wrench when tightening or loosening
fittings.
IDENTIFYING R-134a SYSTEMS & COMPONENTS
To prevent refrigerant cross-contamination, use following
methods to identify R-134a based systems and components.
Fittings & "O" Rings
All R-134a based A/C systems use 1/2" - 16ACME threaded
fittings (identifiable by square threads) and quick-connect service
couplings. See Fig. 1. Besides the use of these fittings, most
manufacturers will use Green colored "O" rings in R-134a systems.
Fig. 1: Identifying R-134a Fittings & Quick-Connect Service Couplings
Courtesy of Audi of America, Inc.
Underhood A/C Specification Labels
Most R-134a based systems will be identified through the use
Other Means Of Identification
Refrigerant R-134a, when viewed through a sight glass, may
have a "milky" appearance due to the mixture of refrigerant and
lubricating oil. As the refrigerant and oil DO NOT exhibit a "clear"
sight glass on a properly charged A/C system, most R-134a systems have
no sight glass.
REFRIGERANT OILS
NOTE: Use ONLY the specified oil for the appropriate system or A/C
compressor. Always check vehicle underhood A/C specification
label or A/C compressor label before adding refrigerant oil
to A/C compressor/system. See Figs. 2 and 3. Always use
refrigerant oil specified on vehicle underhood A/C
specification label if different from the following list.
Refrigerant R-12 based systems use mineral oil, while R-134a
systems use Polyalkylene Glycol (PAG) oils. Using a mineral oil based
lubricant with R-134a will result in A/C compressor failure due to
lack of proper lubrication. The following R-134a refrigerant oils are
currently specified:
Use DENSO/ND-Oil 8 refrigerant oil on Nippondenso
compressors. Use SUN PAG 56 refrigerant oil on Sanden compressors.
NOTE: PAG oils absorb moisture very rapidly, 2.3-5.6 percent by
weight, as compared to a mineral oil absorption rate of
0.005 percent by weight.
SERVICE EQUIPMENT
A/C systems using R-134a refrigerant and PAG lubricants
cannot use R-12 refrigerant or mineral oil lubricants. R-134a
refrigerant is NOT compatible or interchangeable with R-12
refrigerant. Separate sets of hoses, manifold gauge sets and
recovery/recycling equipment are required to service the different
systems. This is necessary to avoid cross-contaminating and damaging
A/C system. A single set of A/C service equipment cannot be cleaned
thoroughly enough to be used with both types of refrigerant.
All equipment used to service A/C systems using R-134a must
be U.L. listed and certified to meet SAE standard J2210. The service
hoses on the manifold gauge set must have manual (turn wheel) or
automatic back-flow valves at the service port connector ends. This
will prevent refrigerant from being released into the atmosphere.
For identification purposes, R-134a service hoses must have a
Black stripe along its length and be clearly labeled SAE J2196/R-134a.
The low pressure test hose is Blue with a Black stripe. The high
pressure test hose is Red with a Black stripe, and the center test
hose is Yellow with a Black stripe.
R-134a manifold gauge sets can be identified by one or all of
the following: Labeled FOR USE WITH R-134a on set, labeled HFC-134a or
R-134a on gauge face, or by a Light Blue color on gauge face. In
addition, pressure/temperature scales on R-134a gauge sets are
different from R-12 manifold gauge sets.
SYSTEM SERVICE VALVES
SCHRADER-TYPE VALVES
NOTE: Although similar in construction and operation to a tire
valve, NEVER replace a Schrader-type valve with a tire valve.
Schrader valve is similar in construction and operation to a
tire valve. When a test gauge hose with built-in valve core depressor
is attached, Schrader stem is pushed inward to the open position and
allows system pressure to reach gauge.
If test hose does not have a built-in core depressor, an
adapter must be used. Never attach hose or adapter to Schrader valve
unless it is first connected to manifold gauge set.
Refrigerant R-12 Schrader-type valve cores have TV5 thread
size. Refrigerant R-134a Schrader-type valve cores use M6 (Metric)
threads. See Fig. 1.
SERVICE VALVE LOCATIONS
SERVICE VALVE LOCATIONS TABLE \
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Vehicle High Low
Diamante ...................... ( 1) ................ ( 2)
Eclipse ....................... ( 1) ................ ( 2)
Galant ........................ ( 1) ................ ( 2)
Mirage ........................ ( 1) ................ ( 2)
Montero ....................... ( 3) ................ ( 3)
Montero Sport ................. ( 1) ................ ( 2)
3000GT ........................ ( 4) ................ ( 2)
( 1) - On high pressure line, between accumulator/receiver-
drier and evaporator.
( 2) - On low pressure line, between evaporator and
compressor.
( 3) - On top of accumulator/receiver-drier.
( 4) - On high pressure line, near receiver-drier.
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REFRIGERANT RECOVERY/RECYCLING
Refrigerant recovery/recycling equipment is used to remove
refrigerant from vehicle's A/C system without polluting atmosphere. To
remove and recycle refrigerant, connect the recovery/recycling
equipment and following the equipment manufacturer's instructions.
Removed refrigerant is filtered, dried and stored in a tank
within the recovery/recycling equipment until it is ready to be pumped
back into vehicle A/C system. With refrigerant stored in the
recovery/recycling equipment, A/C system can be opened without
polluting atmosphere.
NOTE: Separate sets of hoses, gauges and refrigerant
recovery/recycling equipment MUST be used for R-12 and
R-134a based systems. DO NOT mix R-12 and R-134a
refrigerants, as their refrigerant oils and desiccants are
not compatible. It is NOT possible to clean equipment
thoroughly enough to prevent cross-contamination of A/C
systems. On systems with R-134a refrigerant, use
Polyalkylene Glycol (PAG) wax-free refrigerant oil.