IN0002
Example
−
INTRODUCTION REPAIR INSTRUCTIONS
IN−7
7
Author: Date:
1996 LAND CRUISER (RM451U)
(7) When checking continuity at the wire connector, in-
sert the tester probe carefully to prevent terminals
from bending.
(8) When using a vacuum gauge, never force the hose onto a connector that is too large. Use a step −down
adapter for adjustment. Once the hose has been
stretched, it may leak air.
(m) Installation and removal of vacuum hose: (1) When disconnecting vacuum hoses, use tags to
identify how they should be reconnected to.
(2) After completing a job, double check that the vacu-
um hoses are properly connected. A label under the
hood shows the proper layout.
(n) Unless otherwise stated, all resistance is measured at an
ambient temperature of 20° C (68°F). Because the resis-
tance may be outside specifications if measured at high
temperatures immediately after the vehicle has been run-
ning, measurement should be made when the engine has
cooled down.
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
N14063
AC2QD−01
I01386
−
AIR CONDITIONING AIR CONDITIONING SYSTEM
AC−5
1996 LAND CRUISER (RM451U)
ON−VEHICLE INSPECTION
1. INSPECT REFRIGERANT VOLUME
Observe the sight glass on the liquid tube.
Test conditions:
Running engine at 1,500 rpm
Blower speed control switch set at ”HI”
A/C switch ON
Temperature control set at ”MAX. COOL”
Fully open doors
ItemSymptomAmount of refrigerantRemedy
1Bubbles present in sight glassInsufficient*
1. Check for gas leakage with gas leak
tester and repair if necessary
2. Add refrigerant until bubbles disappear
2No bubbles present in sight glassNone, sufficient or too muchRefer to items 3 and 4
3No temperature difference between compressor inlet and outletEmpty or nearly empty
1. Check for gas leakage with gas leaktester and repair if necessary
2. Add refrigerant until bubbles disappear
4Temperature between compressor inlet and outlet is noticeably differentCorrect or too muchRefer to items 5 and 6
5Immediately after air conditioning is turnedoff, refrigerant in sight glass stays clearToo much
1. Discharge refrigerant
2. Evacuate air and charge proper amount of purified refrigerant
6When air conditioning is turned off,
refrigerant foams and then stays clearCorrect−
*: Bubbles in the sight glass with ambient temperatures higher
than usual can be considered normal if cooling is sufficient.
2. INSPECT REFRIGERAT PRESSURE WITH MANIFOLD
GAUGE SET
This is a method in which the trouble is located by using a man-
ifold gauge set. Read the manifold gauge pressure when the
these conditions are established:
Test conditions:
Temperature at the air inlet with the switch set at RECIRC
is 30 − 35° C (86 − 95° F)
Engine running at 1,500 rpm
Blower speed control switch set at high
Temperature control set at max. cool
HINT:
It should be noted that the gauge indications may vary slightly
due to ambient temperature conditions.
(1) Normally functioning refrigeration system.
Gauge reading:
Low pressure side:
0.15 − 0.25 MPa (1.5 − 2.5 kgf/cm
2)
High pressure side:
1.37 − 1.57 MPa (14 − 15 kgf/cm
2)
SightGlass
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
I01387
Condition : Periodically cools and then fails to cool
I01388
Condition: Insufficient cooling
AC−6
−
AIR CONDITIONING AIR CONDITIONING SYSTEM
1996 LAND CRUISER (RM451U)
(2) Moisture present in refrigeration system.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
During operation, pressure on low
pressure side sometimes become
a vacuum and sometime normal
Moisture entered in refrigeration
system freezes at expansion valve
orifice and temporarily stops cycle,
but normal state is restored after a
time when the ice melts Drier in oversaturated state
Moisture in refrigeration system
freezes at expansion valve orifice
and blocks circulation of refriger-
ant(1) Replace condenser
(2) Remove moisture in cycle
through repeatedly evacuating air
(3) Charge proper amount of new
refrigerant
(3) Insufficient cooling
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure low on both low and
high pressure sides
Bubbles seen in sight glass con-
tinuously
Insufficient cooling performance
Gas leakage at some place in re-
frigeration system Insufficient refrigerant in system
Refrigerant leaking
(1) Check for gas leakage with gas
leak detector and repair if neces-
sary
(2) Charge proper amount of re-
frigerant
(3) If indicated pressure value is
near 0 when connected to gauge,
create the vacuum after inspecting
and repairing the location of the
leak
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
I01390
Condition: Insufficient cooling
I01392
Condition: Insufficient coolingNOTE : These gauge indica-
tions are shown when the
refrigeration system has
been opened and the refrig-
erant charged without vacu-
um purging.
AC−8
−
AIR CONDITIONING AIR CONDITIONING SYSTEM
1996 LAND CRUISER (RM451U)
(6) Refrigerant overcharged or insufficient cooling of
condenser
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure too high on both low
and high pressure sides
No air bubbles seen through the
sight glass even when the engine
rpm is lowered Unable to develop sufficient per-
formance due to excessive refrig-
eration system
Insufficient cooling of condenser Excessive refrigerant in
cycle → refrigerant over charged
Condenser cooling → condenser
fins clogged or cooling fan faulty
(1) Clean condenser
(2) Check cooling fan with fluid
coupling operation
(3) If (1) and (2) are in normal
state, check amount of refrigerant
Charge proper amount of refriger-
ant
(7) Air present in refrigeration system
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure too high on both low
and high pressure sides
The low pressure piping hot to
touch
Bubbles seen in sight glass
Air entered in refrigeration system
Air present in refrigeration sys-
tem
Insufficient vacuum purging
(1) Check compressor oil to see if
it is dirty or insuf ficient
(2) Evacuate air and charge new
refrigerant
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
N13795
Quick Disconnect
AdapterCharging
Service Valve Hose
AC2QE−01
N13794
Vacuum Pump
Vacuum Pump Adapter
N13791
Low Pressure
Service Valve
Vacuum Pump Adapter
High Pressure
Service Valve Manifold
Gauge
Set
−
AIR CONDITIONING AIR CONDITIONING SYSTEM
AC−11
1996 LAND CRUISER (RM451U)
EVACUATING
1. CONNECT QUICK DISCONNECT ADAPTERS TO
CHARGING HOSES
2. REMOVE CAPS FROM SERVICE VALVES ON RE- FRIGERANT LINES
3. INSTALL MANIFOLD GAUGE SET
(a) Close both hand valves of manifold gauge set.
(b) Connect the quick disconnect adapters to the service valves.
4. EVACUATE AIR FROM REFRIGERATION SYSTEM
(a) Connect the vacuum pump adapter to the vacuum pump.
(b) Connect the center hose of the manifold gauge set to the vacuum pump adapter.
(c) Open both the high and low hand valves and run the vacu-
um pump.
(d) After 10 minutes or more, check that the low pressure
gauge indicates 750 mmHg (30 in.Hg) or more.
HINT:
If the reading is not 750 mmHg (30 in.Hg) or more, close both
hand valves of manifold gauge set and stop the vacuum pump.
Check the system for leaks and repair as necessary.
(e) Close both the high and low hand valves and stop the vac-
uum pump.
(f) Leave the system in this condition for 5 minutes or more and check that there is no gauge indicator.
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
AC2QF−01
N13790
Low Pressure
Service ValveHigh Pressure
Service Valve
N13792
Gas Leak Detector
AC−12
−
AIR CONDITIONING AIR CONDITIONING SYSTEM
1996 LAND CRUISER (RM451U)
CHARGING
1. INSTALL CHARGING CYLINDER
HINT:
When handling the charging cylinder, always follow the direc-
tion given in the instruction manual.
(a) Charge the proper amount of refrigerant in charging cylin-
der.
(b) Connect the center hose to the charging cylinder.
CAUTION:
Do not open both high and low hand valves of manifold
gauge set.
(c) Open the valve of charging cylinder.
(d) Press the valve core on the side of manifold gauge and expel the air inside of the center hose.
2. INSPECT REFRIGERATION SYSTEM FOR LEAKS
(a) Open the high pressure hand valve and charge refriger- ant.
(b) When the low pressure gauge indicates 98 kPa (1 kgf/cm
2, 14 psi), close the high pressure hand valve.
(c) Using leak detector, check the system for leakage.
(d) If leak is found, repair the faulty component or connection. Add evacuate air from refrigeration system (Refer to 4).
CAUTION:
Use the refrigerant recovery/ recycling machine to recover
the refrigerant whenever replacing parts.
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
−
AIR CONDITIONING AIR CONDITIONING SYSTEM
AC−13
1996 LAND CRUISER (RM451U)
3. CHARGE REFRIGERANT INTO REFRIGERANT SYS-
TEM
If there is no leak after refrigerant leak check charge, the proper
amount of refrigerant into refrigeration system.
CAUTION:
Never run the engine when charging the system through
the high pressure side.Do not open the low pressure hand
valve when the system is being charged with liquid refrig-
erant.
(a) Open the high pressure hand valve fully.
(b) Charge specified amount of refrigerant, then close the high pressure hand valve.
HINT:
A fully charged system is indicated by the sight glass being free
of any bubbles.
4. REMOVE MANIFOLD GAUGE SET
(a) Close both hand valves of manifold gauge set.
(b) Disconnect the quick disconnect adapters from the ser- vice valves.
5. INSTALL CAPS TO SERVICE VALVES ON REFRIGER-
ANT LINES
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
CH0086
CorrectWrong
AC2QG−01
N01881
DENSOBorroughs
−
AIR CONDITIONING DRIVE BELT
AC−15
1342
Author: Date:
1996 LAND CRUISER (RM451U)
DRIVE BELT
ON−VEHICLE INSPECTION
1. INSPECT DRIVE BELT’S INSTALLATION CONDITION
Check that drive belt fits properly in the ribbed groves.
2. INSPECT DRIVE BELT TENSION
Using a belt tension gauge, check the drive belt tension.
Belt tension gauge:
DENSO BTG −20 (95506−00020) or
Borroughs No. BT −33−73F
Drive belt tension:
New belt 100−150 lbf
Used belt 60−100 lbf
HINT:
”New belt” refers to a belt which has been used less than
5 minutes on a running engine.
”Used belt” refers to a belt which has been on a running
engine for 5 minutes or more.
After installing the drive belt, check that it fits properly in
the ribbed grooves.
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010