cooling ISUZU AXIOM 2002 Service Repair Manual

SECTION TABLE OF CONTENTS
GENERAL INFORMATION
0AGeneral Information
0BMaintenance and Lubrication
WORKSHOP MANUAL
HEATING, VENTILATION AND AIR
CONDITIONING
1AHVAC System
STEERING
2APower-Assisted System
AXIOM
(UPR/S)SUSPENSION
3CFront Suspension
3DRear Suspension
3EWheel and Tire System
3FIntelligent Suspension System
DRIVELINE/AXLE
4A1Differential (Front)
4A2Differential (Rear)
4B1Driveline Control System
4B2Driveline Control System (TOD)
4CDrive Shaft System
4D2Transfer Case (TOD)
FOREWORD
This manual includes special notes, impor tant points, service data,
precautions, etc. That are needed for the maintenance, adjustments,
service, removal and installation of vehicle components.
All information, illustrations and specifications contained in this manual
are based on the latest product information available at the time of
publication.
All rights are reserved to make changes at any time without notice.
Arrangement of the material is shown in the table of contents on the
right-hand side of this page. A black spot on the first page of each
section can be seen on the edge of the book below each section title.
These point to a more detailed table of contents preceding each
section.BRAKE
5ABrake Control System
5BAnti-Lock Brake System
5CPower-Assisted Brake System
5D1Parking Brake System (4´4 model)
5D2Parking Brake System (4´2 model)
ENGINE
6AEngine Mechanical
6BEngine Cooling
6CEngine Fuel
6D1Engine Electrical
6D2Ignition System
6D3Starting and Charging System
6EDriveability and Emissions
6FEngine Exhaust
6GEngine Lubrication
6HEngine Speed Control System
6JInduction
TRANSMISSION
7AAutomatic Transmission
7A1Transmission Control System
BODY AND ACCESSORIES
8ALighting System
8BWiper/Washer System
This manual applies to 2002 models.8CEnter tainment
8DWiring System
8EMeter and Gauge
8FBody Structure
8GSeats
8HSecurity and Locks
8ISun Roof/Convertible Top
8JExterior/Interior Trim
RESTRAINTS
9ASeat Belt System
9JSupplemental Restraint System (Air Bag System)
9J1Restraint Control System
CONTROL SYSTEM
10ACruise Control System

0B±5 MAINTENANCE AND LUBRICATION
Explanation of Complete Vehicle
Maintenance Schedule
Brief explanations of the services listed in the preceding
Maintenance Schedule are presented below.
Replace all questionable parts and note any necessary
repairs as you perform these maintenance procedures.
Front and Rear Axle Lubricant
Replacement
Check the lubricant level after every 7,500 miles (12,000
km) of operation and add lubricant to level of filler hole if
necessary.
Replace the front and rear axle lubricant at 15,000 miles
(24,000 km) and 30,000 miles (48,000 km) and after
every 30,000 miles (48,000 km) of operation thereafter.
Air Cleaner Element Replacement
Replace the air cleaner under normal operating
conditions every 30,000 miles (48,000 km).
Operation of the vehicle in dusty areas will necessitate
more frequent replacement.
Spark Plug Replacement
Replace the plugs at 100,000 miles (160,000 km)
intervals with the type specified at the end of this section.
Cooling System Service
Drain, flush and refill system with new engine coolant.
Refer to
ªRecommended Fluids and Lubricantsº in this
section, or ENGINE COOLING (SEC.6B).
Timing Belt Replacement
Replacement of the timing belt is recommended at every
100,000 miles (160,000 km).
Failure to replace the timing belt may result in serious
damage to the engine.
Valve Clearance Adjustment
Incorrect valve clearance will result in increased engine
noise and reduced engine output.
Retorque the camshaft bracket bolts before checking and
adjusting the valve clearance.
Check and adjust the valve clearance whenever
increased engine noise is heard.
Tire Rotation
Rotate tires every 7,500 miles (12,000 km).
Front Wheel Bearings Lubricant
Replacement (Vehicles Produced Before
July/31/2001)
Clean and repack the front wheel bearings at 30,000
miles (48,000 km) intervals.
Refer to DRIVE SHAFT SYSTEM (SEC. 4C).
Front Wheel Bearings Check (Vehicles
Produced After Aug./1/2001)
Inspect hub unit bearing at every 60,000 miles (96,000
km).
If there is abnormal condition, replace hub unit bearing.
Radiator Core and Air Conditioning
Condenser Cleaning
Clean the front of the radiator core and air conditioning
condenser, at 60,000 miles (96,000 km) intervals.
Fluid Level Check
A fluid loss in any system (except windshield
washer) may indicate a problem. Repair the system
at once.
Engine oil level
Check level and add if necessary. The best time to check
the engine oil level is when the oil is warm. After stopping
the engine with the vehicle on a level surface, wait a few
minutes for the oil to drain back to the oil pan. Pull out the
oil level indicator (dipstick). Wipe it clean and push the oil
level indicator back down all the way. Pull out the oil level
indicator, keeping the tip down, and look at the oil level on
it.
Add oil, if needed, to keep the oil level above the ªADDº
mark and between the ªADDº and ªFULLº marks in the
operating range area. Avoid overfilling the engine since
this may cause engine damage. Push the oil level
indicator back down all the way after taking the reading.
If you check the oil level when the oil is cold, do not run the
engine first. The cold oil will not drain back to the pan fast
enough to give a true oil level.
Engine coolant level and condition
Check engine coolant level in the coolant reservoir and
add engine coolant if necessary. Inspect the engine
coolant and replace it if dirty or rusty.
Windshield washer fluid level
Check washer fluid level in the reservoir and add if
necessary.
Power steering system reservoir level
Check and keep at the proper level.
Brake master cylinder reservoir level
Check fluid. Keep fluid at proper level. A low fluid level can
indicate worn disc brake pads which may need to be
serviced.
Hydraulic clutch system
Check fluid level in the reservoir. Add fluid as required.
Battery fluid level
Check fluid level in the battery.
Fluid Leak Check
Check for fuel, water, oil or other fluid leaks by looking at
the surface beneath the vehicle after it has been parked
for a while. Water dripping from the air conditioning
system after use is normal. If you notice gasoline fumes or
fluid at any time, locate the source and correct it at once.
Engine Oil and Oil Filter Replacement
Always use API SE, SF, SG, SH or ILSAC GF±1 quality
oils of the proper viscosity.
When choosing an oil, consider the range of
temperatures the car will be operated in before the next oil
change. Then, select the recommended oil viscosity from
the chart.

0B±6MAINTENANCE AND LUBRICATION
Always change the oil and the oil filter as soon as possible
after driving in a dust storm.
Engine Cooling System Inspection
Inspect the coolant/anti±freeze. If the coolant is dirty or
rusty, drain, flush and refill with new coolant. Keep coolant
at the proper mixture for proper freeze protection,
corrosion inhibitor level and best engine operating
temperature. Inspect hoses and replace if cracked,
swollen or deteriorated. Tighten the hose clamps if
equipped with screw±type clamps. Clean outside of
radiator and air conditioning condenser. Wash filler cap
and neck. To help ensure proper operation, a pressure
test of both the cooling system and the cap is also
recommended.
Exhaust System Inspection
Visually inspect the exhaust pipes, muffler, heat shields
and hangers for cracks, deterioration, or damage.
Be alert to any changes in the sound of the exhaust
system or any smell of fumes. These are signs the system
may be leaking or overheating. Repair the system at
once, if these conditions exist. (See also ªEngine Exhaust
Gas Safetyº and ªThree Way Catalytic Converterº in the
Owner's manual.)
Fuel Cap, Fuel Lines, and Fuel Tank
Inspection
Inspect the fuel tank, the fuel cap and the fuel lines every
60,000 miles (96,000 km) for damage which could cause
leakage.
Inspect the fuel cap and the gasket for correct sealing and
physical damage. Replace any damaged parts.
Drive Belt Inspection
Check the serpentine belt driving for cracks, fraying,
wear, and correct tension every 30,000 miles (48,000
km). Replace as necessary.
Wheel Alignment, Balance and Tires
Operation
Uneven or abnormal tire wear, or a pull right or left on a
straight and level road may show the need for a wheel
alignment. A vibration of the steering wheel or seat at
normal highway speeds means a wheel balancing is
needed. Check tire pressure when the tires are ªcoldº
(include the spare).
Maintain pressure as shown in the tire placard, which is
located on the driver's door lock pillar.
Steering System Operation
Be alert for any changes in steering operation. An
inspection or service is needed when the steering wheel
is harder to turn or has too much free play, or if there are
unusual sounds when turning or parking.
Brake Systems Operation
Watch for the ªBRAKEº light coming on. Other signs of
possible brake trouble are such things as repeated pulling
to one side when braking, unusual sounds when braking
or between brake applications, or increased brake pedaltravel. If you note one of these conditions, repair the
system at once.
For convenience, the following should be done when
wheels are removed for rotation: Inspect lines and hoses
for proper hookup, bindings, leaks, crack, chafing etc.
Inspect disc brake pads for wear and rotors for surface
condition.
Inspect other brake parts, including parking brake drums,
linings etc., at the same time. Check parking brake
adjustment.
Inspect the brakes more often if habit or conditions
result in frequent braking.
Parking Brake and Transmission Park
Mechanism Operation
Park on a fairly steep hill and hold the vehicle with the
parking brake only. This checks holding ability. On
automatic transmission vehicles, shifting from ªPº
position to the other positions cannot be made unless the
brake pedal is depressed when the key switch is in the
ªONº position or the engine is running.
WARNING: B E F O R E C H E C K I N G T H E S TA R T E R
SAFETY SWITCH OPERATION BELOW, BE SURE TO
HAVE ENOUGH ROOM AROUND THE VEHICLE.
THEN FIRMLY APPLY BOTH THE PARKING BRAKE
AND THE REGULAR BRAKE. DO NOT USE THE
ACCELERATOR PEDAL. IF THE ENGINE STARTS,
BE READY TO TURN OFF THE KEY PROMPTLY.
TAKE THESE PRECAUTIONS BECAUSE THE
VEHICLE COULD MOVE WITHOUT WARNING AND
POSSIBLY CAUSE PERSONAL INJURY OR
PROPERTY DAMAGE.
Starter Safety Switch Operation
Check by trying to start the engine in each gear while
setting the parking brake and the foot brake. The starter
should crank only in ªPº (Park) or ªNº (Neutral).
Accelerator Linkage Lubrication
Lubricate the accelerator pedal fulcrum pin with chassis
grease.
Steering and Suspension Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts or signs of
wear. Inspect power steering lines and hoses for proper
hookup, binding, leaks, cracks, chafing, etc.
Body and Chassis Lubrication
Lubricate the key lock cylinders, the hood latch, the hood
and door hinges, the door check link, the parking cable
guides, the underbody contact points, and the linkage.
Propeller Shaft Inspection and Lubrication
Check the propeller shaft flange±to±pinion bolts for
proper torque to 63 Nwm (46 lb ft) for front and rear
propeller shaft.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±19
Evaporation
The refrigerant is changed from a liquid to a gas inside the
evaporator. The refrigerant mist that enters the
evaporator vaporizes readily. The liquid refrigerant
removes the required quantity of heat (latent heat of
vaporization) from the air around the evaporator core
cooling fins and rapidly vaporizes. Removing the heat
cools the air, which is then radiated from the fins and
lowers the temperature of the air inside the vehicle.
The refrigerant liquid sent from the expansion valve and
the vaporized refrigerant gas are both present inside the
evaporator as the liquid is converted to gas.
With this change from liquid to gas, the pressure inside
the evaporator must be kept low enough for vaporization
to occur at a lower temperature. Because of that, the
vaporized refrigerant is sucked into the compressor.
Compression
The refrigerant is compressed by the compressor until it is
easily liquefied at normal temperature.
The vaporized refrigerant in the evaporator is sucked into
the compressor. This action maintains the refrigerant
inside the evaporator at a low pressure so that it can
easily vaporize, even at low temperatures close to 0
C
(32
F).
Also, the refrigerant sucked into the compressor is
compressed inside the cylinder to increase the pressure
and temperature to values such that the refrigerant can
easily liquefy at normal ambient temperatures.
Condensation
The refrigerant inside the condenser is cooled by the
outside air and changes from gas to liquid.
The high temperature, high pressure gas coming from the
compressor is cooled and liquefied by the condenser with
outside air and accumulated in the receiver/drier. The
heat radiated to the outside air by the high temperature,
high pressure gas in the compressor is called heat of
condensation. This is the total quantity of heat (heat of
vaporization) the refrigerant removes from the vehicle
interior via the evaporator and the work (calculated as the
quantity of heat) performed for compression.
Expansion
The expansion valve lowers the pressure of the
refrigerant liquid so that it can easily vaporize.
The process of lowering the pressure to encourage
vaporization before the liquefied refrigerant is sent to the
evaporator is called expansion. In addition, the expansion
valve controls the flow rate of the refrigerant liquid while
decreasing the pressure.
That is, the quantity of refrigerant liquid vaporized inside
the evaporator is determined by the quantity of heat which
must be removed at a prescribed vaporization
temperature. It is important that the quantity of refrigerant
be controlled to exactly the right value.
Compressor
The compressor performs two main functions:It compresses low-pressure and low-temperature
refrigerant vapor from the evaporator into high-pressure
and high-temperature refrigerant vapor to the condenser.
It pumps refrigerant and refrigerant oil through the air
conditioning system.
This vehicle is equipped with a five-vane rotary
compressor.
The specified amount of the compressor oil is 150cc
(5.0 fl. oz.).
The oil used in the HFC-134a system compressor differs
from that used in R-12 systems.
Also, compressor oil to be used varies according to the
compressor model. Be sure to avoid mixing two or more
different types of oil.
If the wrong oil is used, lubrication will be poor and the
compressor will seize or malfunction.
The magnetic clutch connector is a waterproof type.
Magnetic Clutch
The compressor is driven by the drive belt from the crank
pulley of the engine. If the compressor is activated each
time the engine is started, this causes too much load to
the engine. The magnetic clutch transmits the power from
the engine to the compressor and activates it when the air
conditioning is ON. Also, it cuts off the power from the
engine to the compressor when the air conditioning is
OFF. Refer to
Compressor in this section for magnetic
clutch repair procedure.
871RX026
Legend
(1) Magnetic Clutch
(2) Magnetic Clutch Connector
(3) Compressor
Condenser
The condenser assembly is located in front of the radiator.
It provides rapid heat transfer from the refrigerant to the
cooling fins.
Also, it functions to cool and liquefy the high-pressure and
high-temperature vapor sent from the compressor by the
radiator fan or outside air.

1A±20
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
A condenser may malfunction in two ways: it may leak, or
it may be restricted. A condenser restriction will result in
excessive compressor discharge pressure. If a partial
restriction is present, the refrigerant expands after
passing through the restriction.
Thus, ice or frost may form immediately after the
restriction. If air flow through the condenser or radiator is
blocked, high discharge pressures will result. During
normal condenser operation, the refrigerant outlet line will
be slightly cooler than the inlet line.
The vehicle is equipped with the parallel flow type
condenser. A larger thermal transmission area on the
inner surface of the tube allows the radiant heat to
increase and the ventilation resistance to decrease.
The refrigerant line connection has a bolt at the block
joint, for easy servicing.
875R200015
Legend
(1) Pressure Switch
(2) Receiver Drier
(3) Condenser & Receiver Tank Assembly
(4) Condenser Fan
Receiver / Drier
The receiver/drier performs four functions:

As the quantity of refrigerant circulated varies
depending on the refrigeration cycle conditions,
sufficient refrigerant is stored for the refrigeration
cycle to operate smoothly in accordance with
fluctuations in the quantity circulated.

The liquefied refrigerant from the condenser is mixed
with refrigerant gas containing air bubbles. If
refrigerant containing air bubbles. If refrigerant
containing air bubbles is sent to the expansion valve,
the cooling capacity will decrease considerably.
Therefore, the liquid and air bubbles are separated
and only the liquid is sent to the expansion valve.

The receiver/drier utilizes a filter and drier to remove
the dirt and water mixed in the cycling refrigerant.A receiver/drier may fail due to a restriction inside the
body of the unit. A restriction at the inlet to the
receiver/drier will cause high pressure.
Outlet restrictions will be indicated by low pressure and
little or no cooling. An excessively cold receiver/drier
outlet may indicate a restriction.
The receiver/drier of this vehicle is made of aluminum
with a smaller tank. It has a 300cc refrigerant capacity.
The refrigerant line connection has a bolt at the block
joint, for easy servicing.
Triple Pressure Switch (V6, A/T)
Triple pressure switch is installed on the upper part of the
receiver/drier. This switch is constructed with a unitized
type of two switches. One of them is a low and high
pressure switch (Dual pressure switch) to switch ªONº or
ªOFFº the magnetic clutch as a result of irregularly
high±pressure or low pressure of the refrigerant. The
other one is a medium pressure switch (Cycling switch) to
switch ªONº or ªOFFº the condenser fan sensing the
condenser high side pressure.
Compressor
ON
(kPa/psi)OFF
(kPa/psi)
Low-pressure
control206.0+30.0
(29.8+4.3)176.5+24.5
(25.6+3.6)
High-pressure
control2353.6+196.1
(341.3+28.4)2942.0+196.1
(426.6+28.4)
Condenser fanON
(kPa/psi)OFF
(kPa/psi)
Medium-pressure
control1471.0+98.1
(213.3+14.2)1078.7+117.7
(156.4+17.1)
Expansion Valve
This expansion valve is an external pressure type and it is
installed at the evaporator intake port.
The expansion valve converts the high pressure liquid
refrigerant sent from the receiver/drier to a low pressure
liquid refrigerant by forcing it through a tiny port before
sending it to the evaporator.
This type of expansion valve consists of a temperature
sensor, diaphragm, ball valve, ball seat, spring
adjustment screw, etc.
The temperature sensor contacts the evaporator outlet
pipe, and converts changes in temperature to pressure. It
then transmits these to the top chamber of the
diaphragm.
The refrigerant pressure is transmitted to the diaphragm's
bottom chamber through the external equalizing pressure
tube.
The ball valve is connected to the diaphragm. The
opening angle of the expansion valve is determined by
the force acting on the diaphragm and the spring
pressure.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±21
The expansion valve regulates the flow rate of the
refrigerant. Accordingly, when a malfunction occurs to
this expansion valve, both discharge and suction
pressure decreases, resulting in insufficient cooling
capacity of the evaporator.
The calibration has been changed to match the
characteristics of HFC-134a.
874R200003
Legend
(1) Expansion Valve
(2) Evaporator Assembly
Evaporator
The evaporator cools and dehumidifies the air before the
air enters the passenger compartment. High-pressure
liquid refrigerant flows through the expansion valve into
the low-pressure area of the evaporator. The heat in the
air passing through the evaporator core is lost to the
cooler surface of the core, thereby cooling the air.
As heat is lost between the air and the evaporator core
surface, moisture in the vehicle condenses on the outside
surface of the evaporator core and is drained off as water.
When the evaporator malfunctions, the trouble will show
up as an inadequate supply of cool air. The cause is
typically a partially plugged core due to dirt, or a
malfunctioning blower motor.The evaporator core with a laminate louver fin is a
single-sided tank type where only one tank is provided
under the core.
874RY00015
Legend
(1) Evaporator Core
(2) Expansion Valve

1A±22
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Duct Sensor
The duct sensor is the sensor to detect temperature
change of the side of evaporator blower coming by fresh
recirculation of intake door or ªonº ªoffº of compressor.
The temperature is converted to resistant rate.
And it works as thermostat to control to prevent freezing
of evaporator.
This sensor is installed in the upper case of evaporator.
874R200010
Legend
(1) Sensor Part
(2) Evaporator Core
(3) Duct Sensor Assembly
(4) Evaporator Assembly
Refrigerant Line
Restriction in the refrigerant line will be indicated by:
1. Suction line Ð A restricted suction line will cause low
suction pressure at the compressor, low discharge
pressure and little or no cooling.
2. Discharge line Ð A restriction in the discharge line
generally will cause the discharge line to leak.
3. Liquid line Ð A liquid line restriction will be evidenced
by low discharge and suction pressure and
insufficient cooling.
Refrigerant flexible hoses that have a low permeability to
refrigerant and moisture are used. These low
permeability hoses have a special nylon layer on the
inside.
852RS001
Legend
(1) Reinforcement Layer (Polyester)
(2) External Rubber Layer
(3) Internal Rubber Layer
(4) Resin Layer (Nylon)

1A±24
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Diagnosis
Air Conditioning Cycle Diagnosis
ConditionPossible causeCorrection
No cooling or insufficient cooling.Magnetic clutch does not run.Refer to ªMagnetic Clutch Diagnosisº
in this section.
Compressor is not rotating properly.
Drive belt is loose or broken.Adjust the drive belt to the specified
tension or replace the drive belt.
Compressor is not rotating properly.
Magnetic clutch face is not clean and
slips.Clean the magnetic clutch face or
replace.
Compressor is not rotating properly.
Incorrect clearance between
magnetic drive plate and pulley.Adjust the clearance. Refer to
Compressor in this section.
Compressor is not rotating properly.
Compressor oil leaks from the shaft
seal or shell.Replace the compressor
Compressor is not rotating properly.
Compressor is seized.Replace the compressor
Insufficient or excessive charge of
refrigerant.Discharge and recover the
refrigerant. Recharge to the
specified amount.
Leaks in the refrigerant system.Check the refrigerant system for
leaks and repair as necessary.
Discharge and recover the
refrigerant. Recharge to the
specified amount.
Condenser is clogged or insufficient
radiation.Clean the condenser or replace as
necessary.
Temperature control link unit of the
heat unit is defective.Repair the link unit.
Unsteady operation due to a foreign
substance in the expansion valve.Replace the expansion valve.
Poor operation of the electronic
thermostat.Check the electronic thermostat and
replace as necessary.
Insufficient velocity of cooling air.Evaporator clogged or frosted.Check the evaporator core and
replace or clean the core.
Air leaking from the cooling unit or air
duct.Check the evaporator and duct
connection, then repair as
necessary.
Blower motor does not rotate
properly.Refer to Fan Control Lever (Fan
Switch) Diagnosis in this section.
*For the execution of the charging and discharging
operation in the table above, refer to
Recovery,
Recycling, Evacuating and Charging in this section.

HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
1A±27
ConditionPossible causeCorrection
Discharge (High Gauge) Pressure
Abnormally High
Condenser clogged or dirty.Clean the condenser fins
Abnormally HighCooling fan does not operate
properly.Check the cooling fan operation.
Discharge (High Gauge) Pressure
Abnormally High.
Insufficient cooling.Excessive refrigerant in system.Discharge and recover refrigerant.
Recharge to specified amount.
Discharge (High Gauge) Pressure
Abnormally High.
High pressure gauge drop. (After
stopping A/C, the pressure drops
approx. 196 kPa (28 psi) quickly)Air in system.Evacuate and charge refrigerant
system.
Discharge (High Gauge) Pressure
Abnormally Low.
Insufficient coolingInsufficient refrigerant in system.Check for leaks. Discharge and
recover the refrigerant. Recharge to
the specified amount.
Discharge (High Gauge) Pressure
Abnormally Low.
Low pressure gauge indicates
vacuum.Clogged or defective expansion
valve.Replace the expansion valve.
Discharge (High Gauge) Pressure
Abnormally Low.
Frost or dew on refrigerant line
before and after the receiver/drier or
expansion valve, and low pressure
gauge indicates vacuum.Restriction caused by debris or
moisture in the receiver/drier.Check system for restriction and
replace the receiver/drier.
Discharge (High Gauge) Pressure
Abnormally Low.Compressor seal defectiveRepair or replace the compressor.
High and low pressure gauge
balanced quickly. (After turned off
A/C)Poor compression due to a defective
compressor gasket.Repair or replace the compressor.
Suction (Low Gauge) Pressure
Abnormally High.
Low pressure gauge (Low pressure
gauge is lowered after condenser is
cooled by water.)Excessive refrigerant in system.Discharge and recover refrigerant
Recharge to specified amount.
Suction (Low Gauge) Pressure
Abnormally High.
Low pressure hose temperature.
(Low pressure hose temperature
around the compressor refrigerant
Unsatisfactory valve operation due
to defective temperature sensor of
expansion valve.Replace the expansion valve.
around the com ressor refrigerant
line connector is lower than around
evaporator.)Expansion valve opens too long.Replace the expansion valve.
Suction (Low Gauge) Pressure
Abnormally High.
High and low pressure gauge
balanced quickly. (After turned off
A/C)Compressor gasket is defective.Repair or replace the compressor.
Suction (Low Gauge) Pressure
Abnormally Low.
Insufficient cooling.Insufficient refrigerant in system.Check for leaks. Discharge and
recover the refrigerant. Recharge to
specified amount.
Suction (Low Gauge) Pressure
Abnormally Low.
Frost on the expansion valve inlet
lineExpansion valve clogged.Replace the expansion valve.

1A±28
HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Condition CorrectionPossible cause
Suction (Low Gauge) Pressure
Abnormally Low
Receiver/drier inlet and outlet
refrigerant line temperature. (A
distinct difference in temperature
develops.)Receiver/Drier clogged.Replace the receiver/drier.
Suction (Low Gauge) Pressure
Abnormally Low.
Expansion valve outlet refrigerant
line. (Not cold and low pressure
gauge indicates vacuum.)Expansion valve temperature sensor
is defective.Replace the expansion valve.
Suction (Low Gauge) Pressure
Abnormally Low.
When the refrigerant line is clogged
or blocked, the low pressure gauge
reading will decrease, or a vacuum
reading may be shown.Clogged or blocked refrigerant line.Replace refrigerant line.
Suction (Low Gauge) Pressure
Abnormally Low.
Evaporator core is frozen.Thermo switch defective.Replace thermo switch.
Suction (Low Gauge) and Discharge
(High Gauge) Pressure Abnormally
High.Excessive refrigerant in system.Discharge and recover the
refrigerant, the Recharge to the
specified amount.
Insufficient cooling.Condenser clogged or dirty.Clean the condenser fin.
Suction (Low Gauge) and Discharge
(High Gauge) Pressure Abnormally
High.
Suction (Low) pressure hose (Not
cold).Air in system.Evacuate and charge refrigerant.
Suction (Low Gauge) and Discharge
(High Gauge) Pressure Abnormally
Low.
Insufficient coolingInsufficient refrigerant in system.Check for leaks. Discharge and
recover refrigerant. Recharge to
specified amount.
A/C Ð Air Conditioning