low oil pressure TOYOTA CAMRY V20 1986 Service Information

Valve body
spring
SpringFree length
mm (in.)Coil outer
diameter
mm (in.)Total
No. of
coilsColor
(Upper valve body)
Second coast modulator valve
B
1 orifice control valve
Down-shift plug
Throttle valve
Throttle modulator valve
Cut-back valve
No. 1 accumulator control valve
Lock-up relay valve27.5 (1.083)
24.8 (0.976)
29.8 (1.173)
30.7 (1.209)
21.7 (0.854)
21.8 (0.858)
28.1 (1.106)
26.6 (1.047)8.9 (0.350)
8.0 (0.315)
8.7 (0.343)
9.2 (0.362)
9.5 (0.374)
6.0 (0.236)
10.6 (0.417)
10.2 (0.402)14.6
12.0
13.5
9.5
9.5
13.5
13.0
11.5Brown
White
Yellow
Purple
Orange
Red
Yellow
Green
(Lower valve body)
Pressure relief valve
Check valve
Secondary regulator valve
No. 2 accumulator control valve
Second lock valve
3 - 4 shift valve
Low coast modulator valve
1 - 2 shift valve
2 - 3 shift valve
Primary regulator valve11.2 (0.441)
19.9 (0.783)
38.5 (1.516)
23.0 (0.906)
20.7 (0.815)
29.2 (1.150)
20.2 (0.795)
29.2 (1.150)
28.0 (1.102)
64.2 (2.528)6.4 (0.252)
11.0 (0.433)
8.4 (0.331)
6.3 (0.248)
6.1 (0.240)
8.9 (0.350)
7.9 (0.311)
8.9 (0.350)
9.4 (0.370)
18.6 (0.732)7.5
8.5
17.0
12.0
12.0
12.0
11.9
12.0
10.3
12.5None
None
Purple
Gray
Orange
Light green
Purple
Light green
None
None
Valve body
retainerRetainerHeight
mm (in.)Width
mm (in.)Thickness
mm (in.)
(Upper valve body)
Lock-up relay valve
Throttle modulator valve
Second coast modulator valve
Cut-back valve
No. 1 accumulator control valve
B
1 orifice control valve6.5 (0.256)
6.5 (0.256)
6.5 (0.256)
9.2 (0.362)
6.5 (0.256)
11.5 (0.453)5.0 (0.197)
5.0 (0.197)
5.0 (0.197)
5.0 (0.197)
5.0 (0.197)
5.0 (0.197)3.2 (0.126)
3.2 (0.126)
3.2 (0.126)
3.2 (0.126)
3.2 (0.126)
3.2 (0.126)
(Lower valve body)
Primary regulator valve
Secondary regulator valve
No. 2 accumulator control valve
Second lock valve
Low coast modulator valve
1 - 2 shift valve
2 - 3 shift valve
3 - 4 shift valve9.2 (0.362)
15.0 (0.591)
9.2 (0.362)
11.5 (0.453)
11.5 (0.453)
6.5 (0.256)
9.2 (0.362)
6.5 (0.256)5.0 (0.197)
5.0 (0.197)
5.0 (0.197)
5.0 (0.197)
5.0 (0.197)
5.0 (0.197)
5.0 (0.197)
5.0 (0.197)3.2 (0.126)
3.2 (0.126)
3.2 (0.126)
3.2 (0.126)
3.2 (0.126)
3.2 (0.126)
3.2 (0.126)
3.2 (0.126)
Specifications (Cont'd)
- SERVICE SPECIFICATIONSAutomatic Transaxle Transfer (A540E A540H)A-3

AT0179 AT0180
AT7712
Printed
Numbers
AT4499
Oil Seal Ring
A540H A540E
AT2736 AT4340
Oil Seal Ring A540H
(A540H)
Remove the two oil seal rings from the shaft.
INSPECTION OF FORWARD CLUTCH
1. INSPECT CLUTCH PISTON
(a) Check that the check ball is free by shaking the
piston.
(b) Check that the valve does not leak by applying
low-pressure compressed air.
2. INSPECT DISCS, PLATES AND FLANGE
Check if the sliding surfaces of the discs, plates and
flange are worn or burnt. If necessary, replace them.
HINT:

If the lining of the disc is exfoliated or discolored, or
even a part of the printed numbers are defaced,
replace all discs.

Before assembling new discs, soak them in ATF for
at least fifteen minutes.
ASSEMBLY OF FORWARD CLUTCH
1. INSTALL OIL SEAL RINGS
Install the three oil seal rings (A540E) or two oil seal
rings (A540H) to the shaft.
NOTICE: Do not spread the ring ends more than nec-
essary.
HINT: After installing the oil seal rings, check that they
move smoothly.
2. INSTALL CLUTCH PISTON TO CLUTCH DRUM
(a) Install the two new O-rings to the piston.
AT-54- AUTOMATIC TRANSAXLEComponent Parts (Forward Clutch)

(Lower Valve Body)
COMPONENTS
AT4502
AT3483
Retainer Plug3 - 4 Shift Valve PlugRetainer PlugRetainer PlugNo. 2 Accumulator
Control Valve Retainer
2nd lock ValveCheck Ball Secondary Regulator ValveCheck Valve
Oil Strainer Pressure Relief ValveCheck Ball
Plunger Sleeve
The line pressure changes
according to the part of
the plunger sleeve which
comes into contact with
the retainer.
When reassembling the
valve body, position the
retainer in the same
position.
Retainer PlugPlunger RetainerRetainer Shift Valve Plug PlugPrimary Regulator
Valve Plate Washer 2 - 3 Shift Valve Retainer1 - 2 Shift Valve Low Coast Modulator Valve
AT-92- AUTOMATIC TRANSAXLEComponent Parts (Valve Body)

SpringFree length mm (in.)Coil outer diameter
mm (in.)Total No. of coils Color
Pressure relief valve11.2 (0.441) 6.4 (0.252)
7.5
None
Check valve19.9 (0.783) 11.0 (0.433)
8.5 None
Secondary regulator valve38.5 (1.516) 8.4 (0.331)
17.0
Purple
No. 2 accumulator control valve23.0 (0.906)6.3 (0.248)
12.0 Gray
Second lock valve20.7 (0.815) 6.1 (0.240)
12.0 Orange
3 - 4 shift valve29.2 (1.150) 8.9 (0.350)
12.0Light Green
Low coast modulator valve20.2 (0.795) 7.9 (0.311)
11.9 Purple
1 - 2 shift valve29.2 (1.150) 8.9 (0.350)
12.0Light Green
2 - 3 shift valve28.0 (1.102)9.4 (0.370)
10.3 None
Primary regulator valve64.2 (2.528)
18.6 (0.732)
12.5
None
SPECIFICATIONS OF VALVE BODY SPRINGS
HINT: During reassembly please refer to the spring specifications above to help discriminate the different
springs.
SECTIONAL VIEW OF VALVE BODY
AT3604
- AUTOMATIC TRANSAXLEComponent Parts (Valve Body)AT-93

(e) Tighten the O±ring fittings or the bolted type fittings to
the specified torque.
4. WHEN CONNECTING MANIFOLD GAUGE;
(a) Be sure to connect the charging hose end with a pin
to the compressor charging valve.
(b) The letter ºDº engraved near the compressor service
valve indicates the high pressure side, and ºSº indi-
cates the low pressure side. Pay careful attention
when connecting the hose.
(c) Tighten hose by hand.
(d) To prevent loosening of connected hose, do not apply
drops of compressor oil to the seat of connection.
HINT: After connecting the manifold gauge and the refrig±
erant container (service can), discharge any air in the
hoses.
5. WHEN EVACUATING;
Approx. 15 minutes after removal, check the system for
leaks, then take at least another 15 minutes to make sure
the air is fully removed.
6. WHEN HANDLING REFRIGERANT CONTAINER
(SERVICE CAN);
(a) Must never be heated.
(b) Must be kept below 4

°C (1 04°F).
(c) If warming service can with hot water, be careful that
the valve on top of the service can is never immersed
in the water, as the water may permeate into the refrig-
erant cycle.
(d) Empty service cans must never be re±used.
7. WHEN A/C IS ON AND REFRIGERANT GAS IS
BEING REPLENISHED;
(a) If there is not enough refrigerant gas in the refrigerant
cycle, oil lubrication becomes insufficient and com-
pressor burnout may occur, so take care to avoid this.
(b) If the valve on the high pressure side is opened, refrig-
erant flows in reverse and causes the service can to
rupture, so only open and close the vlave on the low
pressure side.
(c) If the service can is inverted and refrigerant is inserted
in a liquid state, the liquid is compressed and the com-
pressor brakes down, so the refrigerant must be in-
serted in a g¿¿seous state.
(d) Be careful not to insert too much refrigerant gas, as
this causes trouble such as inadequate cooling, poor
fuel economy, engine overheat, etc.
8. WHEN USING GAS±CYLINDER TYPE LEAK
DETECTION INSTRUMENT;
(a) As a naked flame is used, first make sure that there are
no flammable substances nearby before using it.
(b) Be careful, as poisonous gas is produced when
refrigerant gas comes in contact with heat parts.
± AIR CONDITIONING SYSTEMGenera! InformationAC±3

*NOTE at No.6
These gauge indications are shown when the refrigeration system has been opened and the re-
frigerant charged without vacuum purging.
(1)Clean condenser
(2)Check fan motor operation
(3)If (1) and (2) are normal,
check refrigerant amount
HINT: Vent out refrigerant
through gauge manifold low
pressure side by gradually
opening valve.
(1)Replace receiver and drier
(2)Check compressor oil to
see if dirty or insufficient
(3)Vacuum purge and charge
new refrigerant Drier in oversaturated state
Moisture in refrigeration
system freezes at expansion
valve orifice and blocks
circulation of refrigerant(1)Replace receiver and
drier
(2)Remove moisture in cycle
through repeated vacuum
purging
(3)Charge refrigerant to proper
amount
Excess refrigerant in cycle ±
refrigerant overcharged
Condenser cooling
insufficient ± condenser fins
clogged or fan motor faulty Unable to develop
±sufficient performance due to
excessive refrigerant in system
Condenser cooling insufficientMoisture entered in
refrigeration system freeze
at expansion valve orifice
and temporarily stops
cycle, but normal state is
restored after a time when the
ice melts
Pressure too high at both low
and high pressure sides
Frost or large amount of dew
on piping at low pressure side(1)Check heat sensing
tube installed condition
(2)If (1) is normal, test
expansion valve in unit
(3) Replace if defective Pressure low at both low and
high pressure sides
Bubbles seen in sight glass
Insufficient cooling
performance
Air present in refrigeration
system
Insufficient vacuum
purging During operation, pressure at
low pressure side sometimes
becomes a vacuum and
sometimes normal
Trouble in expansion valve
or heat sensing tube not
installed correctly
Refrigerant flow out Pressure low at both low and
high pressure sides
Frost on tubes from
receiver to unit(1)Check with leak tester
and repair
(2)Charge refrigerant to
proper amount
Excess refrigerant in low
pressure piping
Expansion valve opened too
wideInsufficient refrigerant in
system
Refrigerant leaking
Pressure too high at both low
and high pressure sidesPressure too high at both
tow and high pressure sidesGas leakage at some place i n
refrigeration system
Refrigerant flow
obstructed by dirt in
receiver
Air entered refrigeration
system Symptom seen in
refrigeration system
Receiver clogged Replace receiver Probable causeDiagnosis
Remedy
No.
± AIR CONDITIONING SYSTEMTroubleshootingAC±19

COMPRESSOR
ON±VEHICLE INSPECTION
1. INSTALL MANIFOLD GAUGE SET
(See page AC±23)
2. RUN ENGINE AT APPROX. 1,500 RPM
3. CHECK COMPRESSOR FOR FOLLOWING:
(1) High pressure gauge reading is not lower and low
pressure gauge reading is not higher than normal.
(b) Metallic sound
(e) Leakage from shaft seal
If defects are found, repair the compressor.
4. CHECK MAGNETIC CLUTCH
(a) Inspect the pressure plate, and the rotor for signs of
oil.
(b) Check the clutch bearings for noise and grease leak-
age.
(e) Using an ohmmeter, measure the resistance of the
stator coil between the clutch lead wire and ground.
Standard resistance: 3.4 ± 3.8
at 20°C (68°F)
If resistance value is not as specified, replace the coil.
(d) Connect the positive (+) lead from the battery to ter-
minal 1, check that the magnetic clutch is energized.
If magnetic clutch is not energized, replace the coil.
NOTICE: Do not short positive (+) lead wire on the vehicle
by applying battery voltage.
Installation of Manifold Gauge Set
1. CLOSE BOTH HAND VALVES OF MANIFOLD GAUGE
SET
2. INSTALL CHARGING HOSES OF GAUGE SET TO
CHARGING VALVES
Connect the low pressure hose to the low pressure charg-
ing valve and the high ..pressure hose to the high pres-
sure charging valve. Tighten the hose nuts by hand.
HINT Do not apply compressor oil to the seat of the con-
nection.
± AIR CONDITIONING SYSTEMRefrigeration SystemAC±23

COMPRESSOR
ON±VEHICLE INSPECTION
1. INSTALL MANIFOLD GAUGE SET
(See page AC±23)
2. RUN ENGINE AT APPROX. 1,500 RPM
3. CHECK COMPRESSOR FOR FOLLOWING:
(1) High pressure gauge reading is not lower and low
pressure gauge reading is not higher than normal.
(b) Metallic sound
(e) Leakage from shaft seal
If defects are found, repair the compressor.
4. CHECK MAGNETIC CLUTCH
(a) Inspect the pressure plate, and the rotor for signs of
oil.
(b) Check the clutch bearings for noise and grease leak-
age.
(e) Using an ohmmeter, measure the resistance of the
stator coil between the clutch lead wire and ground.
Standard resistance: 3.4 ± 3.8
at 20°C (68°F)
If resistance value is not as specified, replace the coil.
(d) Connect the positive (+) lead from the battery to ter-
minal 1, check that the magnetic clutch is energized.
If magnetic clutch is not energized, replace the coil.
NOTICE: Do not short positive (+) lead wire on the vehicle
by applying battery voltage.
Installation of Manifold Gauge Set
1. CLOSE BOTH HAND VALVES OF MANIFOLD GAUGE
SET
2. INSTALL CHARGING HOSES OF GAUGE SET TO
CHARGING VALVES
Connect the low pressure hose to the low pressure charg-
ing valve and the high ..pressure hose to the high pres-
sure charging valve. Tighten the hose nuts by hand.
HINT Do not apply compressor oil to the seat of the con-
nection.
± AIR CONDITIONING SYSTEMCompressorAC±23

3. Hydraulic Control System
CONSTRUCTION
The hydraulic control is composed of an oil pump, rotated by the engine, which supplies hydraulic pres-
sure; a valve body which controls the hydraulic pressure and the opening and closing of the fluid pas-
saged; and a governor valve which supplies hydraulic pressure in accordance with vehicle speed.
OPERATION
Hydraulic pressure supplied by the oil pump is controlled± by the regulator valve; the resulting oil pres-
sure controlled by the regulator valve is called the line pressure.
Line pressure produces the hydraulic pressure for throttle pressure and governor pressure. Also, line
pressure produces hydraulic pressure for the operation of each brake and clutch in the planetary gear
unit.
The throttle valve acts to produce hydraulic pressure, called the throttle pressure, which responds to ac-
celerator pedal modulation. Throttle pressure increases as the accelerator pedal is depressed.
The governor valve produces hydraulic pressure, called the governor pressure, in response to vehicle
speed. Governor pressure increases as vehicle speed increases.
In accordance with the difference between throttle pressure and governor pressure, each shift valve
shifts, the fluid passages to the clutches are brakes in the planetary gear unit are opened and the
clutches and brakes operate, and shift change occurs.
The operation of the hydraulic control system, using the 2±3 shift valve as an example, is shown below;
± AUTOMATIC TRANSAXLEDescription (A140L and A140E)AT±8

EVALUATION
(a) If the measured values at all ranges are higher than specified:
wThrottle cable out of adjustment
w4 Throttle valve defective
Regulator valve defective
(b) If the measured values at all ranges are lower than specified:
wThrottle cable out of adjustment
wThrottle valve defective
wRegulator valve defective
wOil pump defective
wO/D direct clutch defective
(c) If pressure is low in the D range only:
wD range circuit fluid leakage
wForward clutch defective
(d) If pressure is low in the R range only:
wR range circuit fluid leakage
wDirect clutch defective
wFirst and reverse brake defective
± AUTOMATIC TRANSAXLETroubleshooting (Mechanical System Tests) (A140L and
A140E)AT±41