Pontiac tempest 1968 Service Manual page 496

T U R B O H Y D R A - M A T I C TRANSMISSION
7E-61
Approximate Altitude
(Ft. above sea level) D,N,P S or L R
0 150 150 244
2,000 150 150
233
4,000 145 150 222
6,000 138 150 212
8,000 132 150 203
10,000 126 150 194
12,000
121
150 186
14,000 116 150
178
F i g . 7E-172 O i l Pressure Check - Car Stationary, Vacuum Tube Disconnected
III Oil Pressure Check - With Car Stationary and Engine at 1000 rpm
With the transmission oil pressure gauge attached and the vacuum modulator tube
connected for normal modulator operation, the transmission pressures should check
approximately as shown in Fig. 7E-173.
NOTE: Pressures are not significantly affected by altitude or
barometric pressure when the vacuum modulator tube is connected.
Drive, Neutral, Park Super or Lo Reverse
60 150 107
Fig . 7E-173
O i l Pressure Check - C a r S t a t i o n a r y , Vacuum Tube Connected
OIL LEAKS
Before attempting to correct an oil leak, the actual
source of the leak must be determined. In many
cases, the source of the leak can be deceiving due
to wind flow around the engine and transmission.
The suspected area should be wiped clean of all
oil before inspecting for the source of the leak. Red
dye is used in the transmission oil at the assembly
plant and will indicate if the oil leak is from the
transmission.
The use of a black light to identify the oil at
the source of leak is also helpful. Comparing the
oil from the leak to that on the engine or transmis­
sion dipstick (when viewed by black light) will de­
termine the source of the leak.
Oil leaks around the engine and transmission are
generally carried toward the rear of the car by the
air stream. For example, a transmission oil filler
tube to case leak will sometimes appear as a leak
at the rear of the transmission. In determining the
source of an oil leak, it is most helpful to keep the
engine running.
POSSIBLE POINTS OF OIL LEAKS
1. TRANSMISSION OIL PAN L E A K
a. Attaching bolts not correctly torqued.
b. Improperly installed or damaged pan gasket.
c. Oil pan gasket mounting face not flat.
2 . REAR EXTENSION L E A K
a. Attaching bolts not correctly torqued.
b. Rear seal assembly - damaged or improp­
erly installed.
c. Extension to case gasket—damaged or i m ­
properly installed.
d. Porous casting.
3. CASE L E A K
a. Filler pipe O-ring seal-damaged or missing;
misposition of f i l l e r pipe bracket to engine-
loading one side of O-ring.
b. Modulator O-ring seal—damaged or improp­
erly installed.
c. Governor cover, gasket and bolts—damaged,
loose; case face leak.
d. Speedo gear O-ring damaged.
e. Manual shaft seal—damaged, improperly
installed.