Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Service manual

1A–70 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Compressor

Service Precaution

WARNING: THIS VEHICLE HAS A SUPPLEMENTAL
RESTRAINT SYSTEM (SRS). REFER TO THE SRS
COMPONENT LOCATION VIEW IN ORDER TO
DETERMINE WHETHER YOU ARE PERFORMING
SERVICE ON OR NEAR THE SRS COMPONENTS OR
THE SRS WIRING. WHEN YOU ARE PERFORMING
SERVICE ON OR NEAR THE SRS COMPONENTS OR
THE SRS WIRING, REFER TO THE SRS ON-VEHICLE
SERVICE INFORMATION. FAILURE TO FOLLOW
CAUTIONS COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.

CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.

General Description

When servicing the compressor, keep dirt or foreign
material from getting on or into the compressor parts and
system. Clean tools and a clean work area are important
for proper service. The compressor connections and the
outside of the compressor should be cleaned before any
”On–Vehicle” repair, or before removal of the
compressor. The parts must be kept clean at all times and
any parts to be reassembled should be cleaned with
Trichloroethane, naphtha, kerosene, or equivalent
solvent, and dried with dry air. Use only lint free cloths to
wipe parts.
The operations described below are based on bench
overhaul with compressor removed from the vehicle,
except as noted. They have been prepared in order of
accessibility of the components. When the compressor is
removed from the vehicle for servicing, the oil remaining
in the compressor should be discarded and new
compressor oil added to the compressor.
Compressor malfunction will appear in one of four ways:
noise, seizure, leakage or low discharge pressure.
Resonant compressor noises are not cause for alarm;
however, irregular noise or rattles may indicate broken
parts or excessive clearances due to wear. To check
seizure, de–energize the magnetic clutch and check to

see if the drive plate can be rotated. If rotation is
impossible, the compressor is seized. Low discharge
pressure may be due to a faulty internal seal of the
compressor, or a restriction in the compressor. Low
discharge pressure may also be due to an insufficient
refrigerant charge or a restriction elsewhere in the
system. These possibilities should be checked prior to
servicing the compressor. If the compressor is
inoperative, but is not seized, check to see if current is
being supplied to the magnetic clutch coil terminals.
The compressor 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.

DKV-14G Type Compressor

DKV–14G is equipped with five–vane rotary compressor.
These vanes are built into a rotor which is mounted on a
shaft.
When the shaft rotates, the vanes built into the cylinder
block assembly are operated by centrifugal force.
This changes the volume of the spare formed by the rotor
and cylinder, resulting in the intake and compression of
the refrigerant gas. The discharge valve and the valve
stopper, which protects the discharge valve, are built into
the cylinder block assembly. There is no suction valve but
a shaft seal is installed between the shaft and head; a
trigger valve, which applies back pressure to the vanes, is
installed in the cylinder block and a refrigerant gas
temperature sensor is installed in the front head.
The specified quantity of compressor oil is contained in
the compressor to lubricate the various parts using the
refrigerant gas discharge pressure.

871RX002

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–71

Diagnosis

Condition

Possible cause

Correction

Noise from compression

Defective rotor/piston

Replace compressor/cylinder and
shaft assembly

Defective shaft

Replace compressor/cylinder and
shaft assembly

Noise from magnetic clutch

Defective bearing

Replace magnetic clutch

Defective clutch

Replace magnetic clutch

Clearance between drive plate and
pulley not standard

Adjust the clearance or replace
magnetic clutch

Insufficient cooling

Defective gasket

Replace compressor/gasket

Defective rotor/reed valve

Replace compressor/valve plate

Defective trigger valve/suction valve

Replace compressor/suction valve

Not rotating

Defective rotor/piston

Replace compressor/cylinder and
shaft assembly

Defective shaft

Replace compressor/cylinder and
shaft assembly

Rotating parts seized due to
insufficient oil

Replace compressor

Oil and/or gas leakage

Defective seal

Replace compressor/shaft seal

Defective O-ring

Replace

Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Service manual - part 550