GMC 1982 Light Duty Truck Service Manual page 16

Hydro-boost Brake System H ydraulic Pum p
1. Vehicles Equipped With Power Steering.
• On vehicles equipped with power steering, the power
steering pum p is also used as the Hydro-boost
pump. See section on power steering system when
checking fluid level or adding fluid.
2. Vehicles Equipped W ith M anual Steering.
• T he Hydro-boost
equipped with manual steering uses power steering
fluid. See section on power steering system when
checking fluid level or adding fluid.
NOTICE: Power steering fluid and brake fluid cannot be
mixed, since seat dam age may result.
Pow er Steering System
Check the fluid level in the power steering pump at
each oil change and add G M Power Steering Fluid (G M
1050017) or equivalent as needed (Fig. OB-5):
• If fluid is warmed up (about 150°F or 6 6 ° C -h o t to the
touch), it should be between " H o t" and "C old" marks
on the filler cap indcator.
• If cool (about 70°F or 21°C), fluid should be between
" A d d " and "C old" marks.
Fluid does not need periodic changing.
Rear Axle (S tan d ard ) Lubricant
Check lubricant level. Add lubricant, if necessary, to
fill to level of filler plug hole. Use S A E 80W GL-5 or SA E
80W-90 GL-5 or G M 1052271 /1052272 gear lubricant. For
those vehicles driven in Canada, use S A E 80W GL-5 gear
lubricant.
Rear A xle (Locking) Lubricant
Check lubricant level. Add lubricant, if necessary, to
fill to level of filler plug hole. Use gear lubricant G M
1052271/1052272 or equivalent.
A u to m atic Transmission Fluid
Use only au to m a tic
D E X R O N -II or equivalent.
Check the autom atic transmission fluid level at each
engine oil change period. Overfilling can cause foaming and
pum p installed in vehicles
transmission fluid labeled
MAINTENANCE AND LUBRICATION
loss of fluid. Transmission damage can result. Low fluid
level can cause slipping or loss of drive.
A u to m atic transmissions are sometimes overfilled
because the fluid level is checked when the fluid is cold.
W hen cold, the dipstick shows that fluid should be added.
However, the low reading is normal, the level will rise as the
fluid gets warm. The fluid level will increase more than 3/4
inch (19mm) as fluid warms up from 60°F to 180°F (16°C to
82°C).
Check the transmission fluid level with the engine
running, the shift lever in " P a r k " , and the vehicle level.
If the vehicle has just been driven for a long time at
high speed or in city traffic in hot weather, or if the vehicle
has been pulling a trailer, the correct fluid level cannot be
read. W'ait until the fluid has cooled down (about 30
minutes).
Remove the dipstick. Carefully touch the wet end of
the dipstick to find out if the fluid is cool, warm or hot. Wipe
it clean and push it back in until cap seats. Pull out the
dipstick and read the fluid level (Fig. OB-6).
• If it felt cool, about room temperature, the level should
be 1/8 to 3/8 inch (3 to 10mm) below the " A d d " mark.
The dipstick has two dimples below the "A dd " m ark to
show this range.
• If it felt warm, the level should be close to the " A d d "
mark (either above or below).
• If it was too hot to hold, the level should be at the
"F u ll" mark.
• It takes only one pint (0.5 liter) to raise level from
" Add " to " F u ll" with a hot transmission.
M a n u a l Transmission Lubricant
Check lubricant level. Add lubricant, if necessary, to
fill to level of filler plug hole.
Use SA E 80W GL-5 or SA E 80W-90 GL-5 gear
lubricant. For those vehicles driven in Canada, use SA E
80W GL-5 gear lubricant.
W indshield W asher Fluid
Fill the washer ja r only 3/4 full during the winter to
allow for expansion if the tem p e ra tu re should fall low
enough to freeze the solution.
• Check the washer fluid level regularly-do it often when
the weather is bad.
• Use a fluid such as G M Optikleen or equivalent to help
prevent freezing damage, and for better cleaning.
OB-7