cooling ISUZU TROOPER 1995 Workshop Manual

•:1
SECTION TABLE OF CONTENTS
. GENERAL INFORMATION OA General Information OB Maintenance and Lubrication
WORKSHOP MANUAL
HEATING AND AIR CONDITIONING 1A Heating and Ventilation
1B Air Conditioning 1D Compressor Overhaul
TROOPER
FRAME, BUMPERS AND SHEET METAL
2A Frame 2B Bumpers
(UX) 2C Sheet Metal
STEERING, SUSPENSION, WHEELS AND TIRES
3 Diagnosis 3A Front End Alignment 3B1 Power Steering Gear and Pump 3B3 Steering Linkage 3C Front Suspension 3D Rear Suspension 3E Wheels and Tires 3F4 Supplemental Restraint System Steering Wheel
FOREWORD and Column
PROPELLER SHAFT AND AXLE 4A Propeller Shaft This manual includes special notes, important points, service 4B Rear Axle
data, precautions, etc. that are needed for the maintenance, 4C Front Driving Axle
adjustments, service, removal and installation of vehicle BRAKES components. 5A Hydraulic Brakes
·~ m rmation, illustrations and specifications contained in 5A1 Brake Booster System
.. _,. 5A2 Disc Brakes ~ this ma. ~-based D.fl the latest product information 5A3 Rear Wheei_Antilock Brake System (RWAL)
available at the tirrHHrl·publication. 5A4 4-wheel Antilock Brake System (ABS)
5C Parking Brakes All rights are reserved to make changes at any time without ENGINE notice. 6· Engine General Information Arrangement of the material is shown in the table of contents &A General Engine Mechanical
on the right-hand side of this page. A black spot on the first 6A1 3.2L VB Engine
page of each section can be seen on the edge of the book &B Engine Cooling
6C Engine Fuel below each section title. These point to a more detailed table &D Engine Electrical of contents preceding each section. 6D1 Battery 6D2 Cranking System
This manual applies to 1995 models. 6D3 Charging System 6D4-Ignition System 6E2. Driveability and Emissions 6F Engine Exhaust
TRANSMISSION 7A-Automatic Transmission (4L30·E) 7B Manual Transmission 7C Clutch 7D Transfer Case
8 CHASSIS ELECTRICAL
ACCESSORIES 9A Radio 9B Cruise Control 9J Supplemental Restraint System (SRS)-AIR BAG
10 BODY
APPENDIX A CONVERSION TABLES PUBLICATION NO. UXOO-WSM-L0001-00
APPENDIXB HYDRAULIC CIRCUIT DIAGRAM (Automatic Transmission)
© 1994 ISUZU MOTORS LIMITED

(
(
(
MILEAGE/MONTHS
rn
I ffi
IN THOUSANDS
OF
MILES
(USE
ODOMETER READING)
(x 1000
miles)
~ +~
7.5 15 22.5
30
37.5 45 52.5
60
67.5
75
82.5
90
97.5
105
112.5
120 DESCRIPTION
1
CHECK
BATTERY
FLUID
LEVEL
12
2'-'.:j:
:':
';;;;;
I '' ''
,,,,,,,,,:
[}
2
CHECK
ENGINE
COOLANT
LEVEL
12
':iti:·:
(''''/''?
'';?
,,,,,,,;.;.,.,....
,,,~~
3
CHECK
BRAKE
AND
CLUTCH
FLUID
LEVEL
12
:;:;:;:;:·:·:·.
\::':\' '\"':(\':'''''''''
:'·'·'·:·.,.,,,,
d~~~~~~-------------~
)''
'"''''{''''
'}';;o;o;;
l':':':·:o·.·o·····
4
CHECK
FLUID
LEAKS
12
•.•••..••• ,,......
,,,,,,,,,,,
5
* CHANGE
ENGINE
OIL
12
:.•••:•····
f ) : •
: ; ' {
1:':''''
6
*REPLACE
ENGINE
OIL
FILTER
12
{\::::::::;
[:(o:'.
7
CHECK
COOLING
AND
HEATER
HOSES
12
I : ' :
?
,,,.,,,,,.,:,
.. ;
! • !
•••••••••.
8
CHECK
EXHAUST
SYSTEM
12
I
~
J
:
: ••;·,·····,:·:';';·
•••::::::::::·:;.;
I ;J
., ..... .
9
CHECK
FUEL
LINE
AND
FUEL
TANK/CAP
12
10
CHECK
ENGINE
DRIVE
BELTS
24
. .
I
I
11
CHECKTIRESANDWHEELS
12
li
1:;:~:
}::,
..... ::::, .. ,::,:,:,:,·····
j
12
CHECK
STEERING
OPERATION
12
1
r ., .. ,,.,,.
·
I
13
CHECK
BRAKE
LINES
AND
HOSE
12
~
~
<
.,>
/ ':'??i'
}
J
t
''}{
14
CHECK
DISC
BRAKES
12
10
}}
UL
'I I
•....
15
CHECK
BRAKE
PEDAL
PLAY
12
I"
.. )t
16
CHECK
PARKING
BRAKE
12
li
I
17
LUBE
ACCELERATOR
LINKAGE
6
,,.:
....
I
18
CHECK
SUSPENSION
AND
STEERING
12
••·•••·•··•
19
LUBE
BODY
AND
CHASSIS
6
1''''':'''''''''''
20
LUBE
FRONT
AND
REAR
PROPELLER
SHAFT 6
{:
!: • :•••••l
21
CHECK
PROPELLER
SHAFT FLANGE
TORQUE
12
•
22
*CHECK AUTOMATIC TRANSMISSION
FLUID
12
... ,, ,....
@{I{
,,,,,,,,
ttJ
·~+---------------!
23
CHECK
AUTO
CRUISE
CONTROL
LINKAGE
AND
HOSES
12
~ .
:l
!•••:
24
CHECK
CLUTCH
LINES
AND
HOSE
12
25
LUBE
CLUTCH
PEDAL
SPRING,
BUSHING
AND
CLEVIS
PIN
6
l':":"·:"ii
26
CHECK
CLUTCH
PEDAL
FREE
PLAY
12
1/JJ(
21
cHEcK sTARTER SAFETY swiTCH 12
1/,,,,.,,,,,,,,,
,,,,,,,,,
-~~~--~~~~~~-~~~~~[============J
28
CHECK
ACCELERATOR
LINKAGE
12
m ::::::::]
!•'····
'.!
Under
severe driving conditions,
additional
maintenance
is required.
Refer to
"Severe
driving
conditions".
SHADED AREA
INDICATES
SERVICE
TO
BE PERFORMED.
s: ~ 2 -1 m 2 )> 2 n m )> 2 c r­c m ::u n ~ 0 2 Q ~

OB-4 MAINTENANCE AND LUBRICATION
EXPLANATION OF COMPLETE VEHICLE
MAINTENANCE
SCHEDULE
Brief explanations of the services listed in the
preceeding Maintenance Scheduled 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) or operation
thereafter.
MANUAL TRANSMISSION 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 transmission
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 there­
after.
TRANSFER CASE 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 transfer case 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 there­
after.
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 30,000 mile (48,000 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 "Recommended Fluids and Lubricants" in
this section,
or ENGINE COOLING (SEC. 68).
TIMING BELT REPLACEMENT
Replacement of the timing belt is recommended at
every 60,000 miles (96,000 km).
Failure
to replace the timing belt may result in serious
damage
to the engine.
TIRE ROTATION
Rotate tires every 7,500 miles (12,000 km).
POWER STEERING FLUID REPLACEMENT
Drain the power steering fluid and then refill the
system
to the proper level with power steering fluid
after every 30,000 miles (48,000 km) of operation.
See the appropriate section
of this manual for further
details.
FRONT WHEEL HUBS LUBRICANT
REPLACEMENT
Clean and repack the front wheel bearings at 30,000
mile (48,000 km) intervals.
Clean and lubricate the free wheeling hubs at the
same
time the front wheel bearings are serviced.
Refer
to FRONT DRIVING AXLE (SEC. 4C).
RADIATOR CORE AND AIR CONDITIONING
CONDENSER CLEANING
Clean the front of the radiator core and air con­
ditioning condenser, at 60,000 mile (96,000 km)
intervals.
SPARK PLUG WIRE INSPECTION
Check the spark plug wires at 60,000 mile (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
"ADD" mark and between the "ADD" and
"FULL" 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 reservoir and add if necessary.
Power steering system reservoir level-Check
and keep at
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 l~vel 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 (Fig. OB-1).
Always change the oil and the oil filter as soon as
possible after driving in a dust storm.
MAINTENANCE AND LUBRICATION OB-5
ENGINE COOLING SYSTEM INSPECTION
Inspect coolant/anti-freeze. If 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 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 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
"Engine Exhaust Gas Safety" and "Three Way
Catalytic Converter" in 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 belts driving the steering oil pump, the air
conditioning compressor, and the generator
for
cracks, fraying, wear, and correct tension every 30,000
miles (48,000 km). Adjust or 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 "cold" (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 action. 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.

1 B - 2 AIR CONDITIONING
GENERAL DESCRIPTION
AIR CONDITIONING REFRIGERANT CYCLE CONSTRUCTION
Side vent Center vent Side vent Side defrost Defrost Side defrost
Lap vent
-
-
:-·-·.·.·.·.·.·.·.·.·.·.·.·.·.\
·.·.·.·.·.·.·.·.·.·.·.·.·.·.·\
.·.·.·.·.·.··:·
2
.,.,.,.,.,.,.,.,.,.,.,. High pressure, high temperature gas
................... High pressure, high temperature ,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,., mixture of gas and liquid
Cooling air
00
1/?//TJZZ High pressure, medium temperature liquid
----Low pressure, low temperature
6
t
mixture of liquid and gas ..,.,§.."\'"":\"':'0:"'":>'""\\":>"'~ Low pressure, low temperature gas __ _j
1. Compressor 10. Blower motor 2. Magnetic clutch 11. Heater unit 3. Receiver/Drier 12. Heater core 4. Dual pressure switch 13. Temp. control door (Air mix door)
5. Condenser
14. Mode (DEF) control door 6. Evaporator assembly 15. Mode (VENT) control door 7.
Expansion valve 16. Mode (HEAT) control door 8. Temperature sensor
17. Electronic thermostat
9. Evaporator core
Fig. 18-1
Outside air

The refrigeration cycle includes the following four
processes as the refrigerant changes repeatedly
from liquid to gas and back to liquid while circulat­
ing.
EVAPORATION
The refrigerant is changed from a liquid to a gas in­
side
the evaporator. The refrigerant mist that enters
the evaporator vaporizes readily. The liquid refrige­
rant removes
the required quantity of heat (latent
heat of vaporization) from the air around the evap­
orator 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 and 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 tempera­
tures close to ooc (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.
AIR CONDITIONING 1 B -3
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
It 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. And it pumps refrigerant and
refrigerant
oil through the air conditioning system.
This vehicle is equipped with five-vane rotary com­
pressor.
The
thermo sensor is installed to the front head of
the compressor to protect it by stopping its
operation when the refrigerant gas is insufficient or
when the temperature is abnormally high.
• OFF ...... 160 ±soc (320.0 ± 9.0°F)
• ON
...... 135 ±soc (27S.O ± 9.0°F)
The specified amount of the compressor oil is 1SOcc
(S.O 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 ac­
tivated 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 com­
pressor 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".
(Magnetic clutch repair procedure can be found in
Section 1 D.)

1 B - 4 AIR CONDITIONING
Compressor
Thermosensor
Magnetic clutch
Fig. 18-2
CONDENSER
The condenser assembly is located in front of the
radiator. It carries the refrigerant and cooling fins to
provide rapid transfer of heat.
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.
A condenser
may malfunction in two ways: it may
leak, or it may be restricted. A condenser restric­
tion 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 from immediately after the
restriction. If air flow through the condenser or
radiator is blocked, high discharge pressures will
result. During normal condenser operation, the re­
frigerant 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.
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 refrigera­
tion 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 bub­
bles. 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 dryer to
remove the dirt and water mixed in the cycling
refrigerant.
• The sight glass, installed atop the receiver/
drier, show the state of the refrigerant.
A receiver/drier may fail due to a restriction inside
the body of the unit. A restriction at inlet to the re­
ceiver/drier
will cause high pressures.
Outlet restrictions will be indicated by low pressure
and
little or no cooling. An excessively cold re­
ceiver/drier
outlet may indicate a restriction.
The receiver/drier
of this vehicle is made of alu­
minum with a smaller tank. It has 300 cc refrigerant
capacity.
The
refrigerant line connection has a bolt at the
block joint, for easy servicing.
PRESSURE SWITCH
The pressure switch (Dual pressure switch) is in­
stalled on the upper part of the receiver/drier, to
detect excessively high pressure (high pressure
switch) and prevent compressor seizure due to the
refrigerant leaking (low pressure switch), so that the
compressor is able to turned "ON" or "OFF".
The pressure characteristics of HFC-134a refrigerant
differ from those of R-12. Thus, the pressure switch
operation for HFC-134a systems has been changed
from R-12.
• Compressor ON · OFF (kPa/psi)
Low-pressure control
ON: 186.3 ± 29.4 (27.0 ± 4.3)
OFF: 176.5 ± 19.6 (25.6 ± 2.8)
High-pressure
control
ON: 2059.4 ± 196.1 (341.3 ± 28.4)
OFF: 2942.0 ± 196.1 (426.6 ± 28.4)

Fig. 18-3
EXPANSION VALVE
This expansion valve is 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 tempera­
ture 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 dia­
phragms 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.
The
expansion valve regulates the flow rate of the
refrigerant. Accordingly, when a malfunction occurs
to this expansion valve, both discharge and suction
pressures
get low, resulting in insufficient cooling
capacity of the evaporator.
The
calibration has been changed to match the
characteristics of HFC-134a.
AIR CONDITIONING 1 B - 5
Fig. 18-4
EVAPORATOR
The evaporator cools and dehumidifies the air
before the air enters the vehicle. 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 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.
Evaporator core
=
Fig. 18-5

1 B-6 AIR CONDITIONING
ELECTRONIC THERMOSTAT
The thermostat consists of the thermosensor and
thermostat unit which functions electrically to
reduce the noises being generated while the system
is in operation.
The
electronic thermosensor is mounted at the
evaporator core outlet and senses the temperature
of the cool air from the evaporator. Temperature
signals are input to the thermostat unit. This
information is compared by the thermo unit and the
results in output to operate the A/C Thermostat
relay and turn the magnetic clutch "ON" or "OFF"
to prevent evaporator freeze-up.
A characteristic
of the sensor is that the resistance
decreases as the
temperature increases and the
resistance increases as
the temperature decreases.
Thermosensor Clip
Evaporator
unit
Fig. 18-6
REFRIGERANT LINE
Restrictions in the refrigerant line will be indicated by:
1. Suction line; A restricted suction line will cause
low suction pressure at the compressor, low
discharge pressure and little or not cooling.
2. Discharge line; A restriction in the discharge
line generally will cause the discharge line to
leak.
3. Liquid line; A liquid line restriction will be
evidenced
by low discharge and suction
pressure and
insufficient cooling.
Refrigerant flexible hoses that have a low per­
meability to refrigerant and moisture are used.
These
low permeability hoses have a special nylon
layer on the inside.
Refrigerant
lines given in the illustration (Fig. 1 B-8).
Resin layer (Nylon)
Reinforcement layer (Polyester)
External rubber layer
Fig. 1 B-7
•

DIAGNOSIS
AIR CONDITIONING CYCLE DIAGNOSIS
TROUBLE POSSIBLE CAUSE
No cooling or 1. Magnetic clutch does not run
insufficient cooling
2. Compressor is not rotating properly
• Drive belt loosened or broken
• Magnetic clutch face is not
clean and slips
• Incorrect clearance between
magnetic
drive plate and pulley
• Compressor oil leaks from shaft
seal
or shell
• Compressor seized
3. Insufficient or excessive charge of
refrigerant
4. Leaks in the refrigerant system
5. Condenser clogged or insufficient
radiation
6. Temperature control link unit of the
heater
unit defective
7. Unsteady operation due to foreign
substance in expansion valve
8. Poor operation of electronic
thermostat
Insufficient velocity 1. Evaporator clogged or frosted
of cooling air
2. Air leaking from cooling unit or air
duct
3. Blower motor does not rotate prop-
erly
AIR CONDITIONING 1 B - 9
CORRECTION
• Refer to "MAGNETIC CLUTCH
• DIAGNOSIS" in this section
• Adjust the drive belt to the specified
tension
or replace the drive belt
• Clean the magnetic clutch face or
replace
• Adjust the clearance (Refer to Sec-
• tion 1 D "COMPRESSOR OVER-
HAUL")
• Replace the compressor
• Replace the compressor
• Discharge and recover refrigerant.
Recharge
to specified amount.
• Check refrigerant system for leaks
and repair
as necessary
Discharge and recover refrigerant.
Recharge
to specified amount.
• Clean the condenser or replace as
necessary
• Repair the link unit
• Replace the expansion valve
• Check electronic thermostat and
replace
as necessary
• Check evaporator core and replace
or clean the core
• Check evaporator and duct connec-
tion, then repair as necessary
• Refer to Section 1A for "FAN CON-
TROL KNOB
(FAN SWITCH) DIAG-
NOSIS"
* For the execution of the charging and discharging operation in the table above, refer to the "RECOVERY,
RECYCLING, EVACUATING
AND CHARGING" in this section.