air conditioning TOYOTA T100 1996 Factory Owner's Manual

Downloaded from www.Manualslib.com manuals search engine N06110
Sight Glass
AC0EX−02
− AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC−3
1996 TOYOTA T100 (RM449U)
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 on ”HI” position
A/C switch ON
Temperature control dial on ”COOL” position
Fully open the doors
ItemSymptomAmount of refrigerantRemedy
1Bubbles present in sight glassInsufficient*
(1) Check for gas leakage with gas leak de-
tector and repair if necessary
(2) Add refrigerant until bubbles disappear
2No bubbles present in sight glassNone, sufficient or too muchRefer item 3 and 4
3No temperature difference between com-
pressor inlet and outletEmpty or nearly empty
(1) Check for gas leakage with gas leak de-
tector 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 turned
off, 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, refriger-
ant foams and then stays clearCorrect−
*: Bubbles in the sight glass with ambient temperatures higher than usual can be considered normal if cooling
is sufficient.

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I01387
Condition : Periodically cools and then fails to cool AC−4
− AIR CONDITIONINGAIR CONDITIONING SYSTEM
1996 TOYOTA T100 (RM449U)
2. INSPECT REFRIGERANT PRESSURE WITH MAN-
IFOLD 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 these
conditions are established.
Test conditions:
Temperature at the air inlet with the switch set
at RECURC is 30 − 35 °C (86 − 95 °F)
Engine running at 1500 rpm
Blower speed control switch on ”HI” position
Temperature control dial on ”COOL” position
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 − 16 kgf/cm
2)
(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 receiver
(2) Remove moisture in cycle
through repeatedly evacuating air
(3) Charge proper amount of new
refrigerant

Downloaded from www.Manualslib.com manuals search engine I01388
Condition: Insufficient cooling
I01389
Condition: Insufficient cooling
− AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC−5
1996 TOYOTA T100 (RM449U)
(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
(4) Poor circulation of refrigerant
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
 Pressure low in both low and
high pressure sides
 Frost on tube from receiver to
unit
Refrigerant flow obstructed by dirt
in receiverReceiver cloggedReplace receiver

Downloaded from www.Manualslib.com manuals search engine I01449
Condition: Does not cool (Cools from time to time in some cases)
I01390
Condition: Insufficient cooling AC−6
− AIR CONDITIONINGAIR CONDITIONING SYSTEM
1996 TOYOTA T100 (RM449U)
(5) Refrigerant does not circulate
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
 Vacuum indicated on low pres-
sure side, very low pressure indi-
cated on high pressure side
 Frost or dew seen on piping be-
fore and after receiver/ drier or ex-
pansion valve Refrigerant flow obstructed by
moisture or dirt in refrigeration sys-
tem
 Refrigerant flow obstructed by
gas leakage from expansion valve
Refrigerant does not circulate
(1) Check expansion valve
(2) Clean out dirt in expansion
valve by blowing with air
(3) Replace receiver
(4) Evacuate air and charge new
refrigerant to proper amount
(5) For gas leakage from expan-
sion valve, replace expansion
valve
(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-
erant in system
 Insufficient cooling of condenser Excessive refrigerant in
cycle → refrigerant overcharged
 Condenser cooling
insufficient → condenser fins
clogged of cooling fn 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

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Condition: Insufficient cooling
NOTE : These gauge indica-
tions are shown when the
refrigeration system has
been opened and the refrig-
erant charged without vacu-
um purging.
I01450
Condition: Insufficient cooling
− AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC−7
1996 TOYOTA T100 (RM449U)
(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
the 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 insufficient
(2) Evacuate air and charge new
refrigerant
(8) Expansion valve improperly
Mounted/ Heat sensing tube defective
(Open too wide)
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
 Pressure too high on both low
and high pressure sides
 Frost or large amount of dew on
piping on low pressure side
Trouble in expansion valve or heat
sensing tube not installed correctly
 Excessive refrigerant in low
pressure piping
 Expansion valve opened too
wide(1) Check heat sensing tube
installed condition
(2) Check expansion valve
Replace if defective

Downloaded from www.Manualslib.com manuals search engine I01393
Condition : Does not cool AC−8
− AIR CONDITIONINGAIR CONDITIONING SYSTEM
1996 TOYOTA T100 (RM449U)
(9) Defective compression compressor
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
 Pressure too high on low and
high pressure sides
 Pressure too low on high pres-
sure side
Internal leak in compressor
 Compression defective
 Valve leaking or broken sliding
parts
Repair or replace compressor
3. INSPECT IDLE−UP SPEED
(a) Warm up engine.
(b) Inspect idle−up speed when the these conditions are es-
tablished.
Warm up engine
Blower speed control switch at ”HI” position
A/C switch ON
Temperature control dial at ”COOL” position
Magnetic clutch conditionIdle−up speed
3RZ−FE Engine−
Magnetic clutch not engaged700 ± 50 rpm
Magnetic clutch engaged900 ± 50 rpm
5VZ−FE Engine−
Magnetic clutch not engaged700 ± 50 rpm
Magnetic clutch engaged850 ± 50 rpm
If idle speed is not as specified, check idle control system.
4. INSPECT FOR LEAKAGE OF REFRIGERANT
(a) Perform in these conditions:
Stop engine.
Secure good ventilation (If the gas leak detector
may not react to volatile gases which are not refrig-
erant, such as evaporated gasoline and exhaust
gas.)
Repeat the test 2 or 3 times.
Make sure that there is some refrigerant remaining
in the refrigeration system.
When compressor is OFF: approx. 392 − 588 kPa
(4 − 6 kgf/ cm
2, 57 − 85 psi)

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Drain Hose
N17949
− AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC−9
1996 TOYOTA T100 (RM449U)
(b) Bring the gas leak detector close to the drain hose before
performing the test.
HINT:
After the blower motor has stopped, leave the cooling unit
for more than 15 minutes.
Expose the gas leak detector sensor under the drain
hose.
When bring the gas leak detector close to the drain hose,
make sure that the gas leak detector does not react to the
volatile gases.
If such reaction is unavoidable, the vehicle must be lifted up.
(c) If gas leak is not detected on the drain hose, remove the
blower resistor from the cooling unit. Then insert the gas
leak detector sensor into the unit and perform the test.
(d) Disconnect the connector and leave the pressure switch
for approx. 20 minutes. Then bring the gas leak detector
close to the pressure switch and perform the test.
(e) Bring the gas leak detector close to the refrigerant lines
and perform the test.

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N13793
Charging Cylinder High Pressure
Service Valve Low Pressure
Service ValvePush
Air
N13792
Gas Leak
Detector
− AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC−11
1996 TOYOTA T100 (RM449U)
CHARGING
1. INSTALL CHARGING CYLINDER
HINT:
When handling the charging cylinder, always follow the direc-
tions given in the instruction manual.
(a) Charge the proper amount of refrigerant into the charging
cylinder.
(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 a gas leak detector, check the system for leakage.
If leak is found, repair the faulty component or connection.
CAUTION:
Use the refrigerant recovery/ recycling machine to recover
the refrigerant whenever replacing parts.

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Low Pressure
Service Valve
High Pressure
Service Valve
AC−12
− AIR CONDITIONINGAIR CONDITIONING SYSTEM
1996 TOYOTA T100 (RM449U)
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 refrigerant.
(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. SET OFF 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

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N13105
Compressor
Engine Room Relay Block
 Heater Main Relay
(Marking: HEATER)
Receiver
Condenser
Blower Unit
 Blower Motor
 Blower Resistor
Heater Control Assembly
 Blower Speed Control Switch
 Defroster Mode Switch Heater Unit
 Heater Radiator
A/C Switch
Cooling Unit
 Evaporator
 Expansion Valve
 A/C Amplifier
 Thermistor
 Pressure Switch
− AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC−13
1996 TOYOTA T100 (RM449U)
LOCATION