1987 MAZDA 626 Rear brake

TROUBLESHOOTING 7C
STEP 3 (TIME LAG TEST)
When the selector lever is shifted while the engine is idling, there is a certain time lapse, or time lag,
before shock is felt. This time lag test checks the condition of the front, rear, and one-way clutch, low
and reverse brake, and orifice check valve.
Preparation
Follow the test preparation procedure shown in STEP 2 (STALL TEST).
Procedure
1. Start the engine and verify that the idle speed is 950tso rpm.
2. Shift from N range to D range
3. Measure the time it takes from shifting until shock is felt with a stop watch.
4. Shift the selector to N range and run the engine at idle for one minute or more.
5. Perform the test for N range to R range in the same manner.
Note
Make three measurements for each test and take the average value.
Specified time lag: N D range 0.5—1.0 second
N R range 0.5—1.0 second
Evaluation
Condition Possible Cause
N -» D shift More than specification
Insufficient line pressure
N -» D shift More than specification Rear clutch slipping N -» D shift More than specification
One-way clutch slipping N -» D shift
Less than specification N-D accumulator not operating properly
N-R shift
More than specification
Insufficient line pressure
N-R shift
More than specification Low and reverse brake slipping
N-R shift
More than specification
Front clutch slipping N-R shift
Less than specification Stuck orifice check valve
N-R shift
Less than specification Excessive line pressure
76G07C-027
7C-17

TROUBLESHOOTING 7C
Specified line pressure:
Range Pressure kPa (kg/cm2, psi) Range
Idle Stall
D 294-392 (3-4, 43-57) 883-1079 (9—11, 128-156)
2 785—1177 (8—12, 114—171) 785-1177 (8—12, 114-171)
1 294-392 (3-4, 43—57) 883-1079 (9—11, 128—156)
R 392-687 (4-7, 57-100) 1570—1864 (16—19, 228-270)
76G07C-031
Evaluation
Condition Possible cause
Below standard
In all ranges
Worn oil pump
Below standard
In all ranges Fluid leakage from the oil pump, control valve, or transaxle case
Below standard
In all ranges
Stuck pressure regulator valve Below standard
In D, 1, 2 ranges Fluid leakage from the rear clutch or governor hydraulic circuit, or both
Below standard
In R range only Fluid leakage from the low and reverse brake hydraulic circuit
Excessive line pressure at idle Leaking or disconnected vacuum hose Excessive line pressure at idle
Leaking vacuum diaphragm
76G07C-032
76G07C-033
Vacuum
gauge Line
pressure
Governor pressure
At Atmosphere Radical line Read
& 200 mmHg pressure governor
(7.87 inHg) reduction
Line Pressure Cutback Point
1. Connect the SST to the line pressure output point
and the governor pressure output point in the trans-
axle case, and place the gauges inside the vehicle.
2. Disconnect the hose to the vacuum diaphragm,
and plug it.
3. Connect a vacuum pump to the vacuum di-
aphragm, and place the pump inside the vehicle.
4. Gradually accelerate the vehicle in D range.
5. Read the governor pressure at the point where the
line pressure suddenly drops.
6. Apply 200 mmHg (7.87 inHg) vacuum, and re-
peat steps 4 and 5.
Standard
Vacuum mmHg (InHg) Governor pressure kPa (kg/cm2, psi)
Atmospheric pressure 98-157 (1.0—1.6, 14-23)
200 (7.87) 39-98 (0.4-1.0, 6—14)
Evaluation
Incorrect pressures
1. Missing diaphragm rod or rod length incorrect, or
both.
2. Stuck valve in control valve.
76G07C-034
7C—21

DISASSEMBLY 7C
DISASSEMBLY - STEP 2 76G07C-086
76G07C-087
1. Anchor-end bolt and
locknut
2. Brake band
3. Strut
4. Front clutch
5. Rear clutch
6. Rear clutch hub assembly
7. Planetary carrier (front)
8. Seal sleeve
9. Sun gear and spacer
10. Connecting shell
11. Servo
12. Transaxle case
13. Governor
7C—41

7C DISASSEMBLY
Procedure
1. Remove the anchor-end bolt and locknut.
76G07C-088
2. Remove the brake band and strut.
Note
Use a piece of wire to secure the brake band
so that it is not damaged by being stretched.
76G07C-089
3. Remove the front clutch.
76G07C-090
4. Remove the rear clutch.
76G07C-091
7C-42

7C ASSEMBLY
19. Install the rear clutch.
76G07C-291
76G07C-292
20. Apply petroleum jelly to the thrust bearing to se-
cure it; then install it into the rear clutch.
Thrust bearing outer diameter:
41.9 mm (1.65 in)
21. Install the front clutch.
76G07C-293
22. Install the brake band and strut.
23. Install the anchor-end bolt and locknut; then loosely
tighten the anchor-end bolt.
76G07C-294
7C-110

HYDRAULIC CIRCUIT 7C
R RANGE
Band servo
Release side
Oil cooler
Low and reverse brake 1 pressure Vacuum diaphragm Kick-down solenoid Rear clutch pressure
Front clutch pressure
Downshift valve H Oil pump Vacuum throttle valve
Throttle backup valve
Orifice check valve
Modifier 15| valve
2-3 shift valve
Second lock valve
Orifice valve Pressure regulator valve
Line pressure t4s2
Operating line pressure
Governor pressure
Torque converter
Throttle pressure Secondary x governor valve Primary governor valve
76G07C-340
7C—127

7C HYDRAULIC CIRCUIT
N RANGE
Oil cooler
Low and reverse brake •l pressure Vacuum diaphragm Kick-down solenoid
Rear clutch pressure
Front clutch pressure
Downshift valve 11 Oil pump Throttle backup valve
Vacuum throttle valve
x 18 Orifice YjI check valve H [ Throttle relief I valve
Modifier 15| valve Orifice check
I
valve
Orifice check valve 11 j! Pressure regulator valve
Line pressure
Governor pressure
Torque converter
Throttle pressure Primary governor valve Secondary x governor valve
76G07C-341
7C—128

HYDRAULIC CIRCUIT 7C
D RANGE (1ST GEAR)
Band servo
Kick-down solenoid
Downshift valve Throttle backup valve
76G07C-342
Pressure regulator valve
Line pressure
Operating line pressure
Governor pressure
Torque converter
Throttle pressure
Orifice ch< valve
Secondary * Primary x governor valve governor valve
Vacuum | throttle valve
valve
Apply side
Release side
Low and reverse brake pressure
Rear clutch pressure
Vacuum diaphragm
Oil pump
Throttle relief valve
J Orifii check valve
Orifice check valve
Front clutch pressure
Modifier 1! valve
7C—129