Pontiac FIREBIRD 1972 Service Manual page 1042

7G-4 1972 PONTIAC SERVICE MANUAL
Oil
pressures indicated are a t zero output speed, vacuum line DISCONNECTED and with engine speed
set to
1200
rpm (service brake on):
I
Pressures are approximate
(* 5
psi)
I
Approximate Altitude
(Feet above Sea Level)
Fig. 7G-4 Oil Pressure Check
-
Vehicle Stationary
TURBO HYDRA-MATIC (M-38) TROUBLE DIAGNOSIS GUIDE
N O DRIVE I N DRIVE RANGE
Park
Neutral
Drive
(Install pressure gauge)
1. Low Oil Level
-
correct level and check for external
leaks or defective vacuum modulator (leaking dia-
phragm will evacuate oil from unit).
Super
or
Low
2. Manual Linkage
-
misadjusted, correct alignment to
manual lever shift quadrant is essential.
R e v e l ~ e
3. Low Oil Pressure
-
refer to LOW LINE PRESSURE
below.
4. Forward Clutch:
a. Forward clutch does not apply
-
piston cracked;
seals missing or damaged; clutch plates burned
(see BURNED CLUTCH PLATES below).
b. Pump feed circuit-to-forward clutch oil seal rings
missing or broken on pump cover; leak in feed
circuits; pump-to-case gasket mispositioned or
damaged; clutch drum ball check stuck or miss-
ing.
5.
Low
&
Reverse Roller Clutch Assembly- broken
spring, damaged cage or installed backwards.
HlGH OR L O W OIL PRESSURE
(Refer to OIL PRESSURE CHECKS)
HlGH
LINE PRESSURE
1. Vacuum Leak:
a. Vacuum line disconnected.
b. Leak in line from engine to modulator.
c. Improper engine vacuum.
d. Leak in vacuum-operated accessory (hoses,
vacuum advance, etc.).
2. Modulator:
a. Stuck modulator valve.
b. Water in modulator.
c. Damaged, not operating properly.
3. Detent System
-
detent valve or cable stuck in detent
position.
4. Valve Body:
a. Pressure regulator and/or boost valve stuck.
b. Boost valve sleeve broken or defective.
c. Incorrect pressure regulator valve spring.