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Brakes
Brake Fluid
If your vehicle has
hydraulic brakes, there
is a brake master
cylinder in the engine
compartment on the
driver side of the vehicle.
Refer to the
Maintenance Schedule
to determine when to
check the brake fluid.
{CAUTION:
Do not add brake uid before you check
the level. If you do, you could get too
much brake uid. Brake uid could spill
on the hot engine and it can catch re.
You could be burned and your vehicle
could be damaged. See “Checking Brake
Fluid” in this section.
Checking Brake Fluid
Apply the brake pedal several times with the
ignition off. The brake fluid reservoir is in
the engine compartment on the driver side of the
vehicle. Clean one of the reservoir caps and
the area around the cap, and remove it.
The fluid level should be
even with the bottom
ring of the filler opening.
If it is low, add enough
fluid to fill the reservoir to
the proper level.
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What to Add
Use the proper fluid listed in the Maintenance
Schedule. Use new brake fluid from a sealed
container only.
Always clean the brake fluid reservoir cap/cover
and the area around the cap/cover before
removing it. This will help keep dirt from entering
the reservoir.
{CAUTION:
With the wrong kind of uid in the brake
system, the brakes may not work well, or
they may not even work at all. This could
cause a crash. Always use the proper
brake uid.Notice:
Using the wrong uid can badly damage
brake system parts. For example, just a few
drops of mineral-based oil, such as engine
oil, in the brake system can damage brake
system parts so badly that they will have to
be replaced. Do not let someone put in the
wrong kind of uid, and do not use DOT-5
silicone brake uid.
If you spill brake uid on your vehicle’s
painted surfaces, the paint nish can be
damaged. Be careful not to spill brake uid
on your vehicle. If you do, wash it off
immediately. SeeWashing Your Vehicle on
page 335.
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Four-Wheel Disc Brakes
(Hydraulic Only)
Your vehicle has four-wheel disc brakes.
Some driving conditions or climates may cause a
brake squeal when the brakes are first applied
or lightly applied. This does not mean something
is wrong with the brakes.
Brake linings should always be replaced as
complete axle sets.
Four-Wheel and Six-Wheel Drum
Brakes (Air Only)
The brake drums should be removed and
inspected each time the tires are removed for
rotation or changing. When you have the
front brakes replaced, have the rear brakes
inspected, too.
Brake linings should always be replaced as
complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not return
to normal height, or if there is a rapid increase in
pedal travel. This could be a sign that brake service
is needed.
Brake Adjustment
Every time you make a brake stop, the brakes
adjust for wear.
Brake Adjustment on Air Braked
Vehicles
Your vehicle has automatic slack adjusters.
Every time you make a brake stop, the brakes
automatically adjust for wear. Slack adjusters
should never be manually adjusted to correct
excessive brake chamber pushrod stroke.
Excessive brake chamber pushrod stroke means
that the brake system needs to be serviced by
a qualified service technician.
Notice:Do not manually adjust automatic slack
adjusters. Manual adjustment of the automatic
slack adjusters can result in a degradation of
the slack adjuster performance over time.
If the brake chamber pushrod stroke is out of
adjustment, the brake system needs to be
serviced by a quali ed service technician.
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Replacing Brake System Parts
The braking system on a vehicle is complex.
Its many parts have to be of top quality and work
well together if the vehicle is to have really
good braking. Your vehicle was designed and
tested with top-quality GM brake parts. When
you replace parts of the braking system — for
example, when the brake linings wear down and
you need new ones put in — be sure you get
new approved GM replacement parts. If you do
not, the brakes may no longer work properly.
For example, if someone puts in brake linings that
are wrong for your vehicle, the balance between
the front and rear brakes can change — for
the worse. The braking performance you have
come to expect can change in many other ways
if someone puts in the wrong replacement
brake parts.
Air Brake Systems
If your vehicle has air brakes, it is important to
get rid of moisture in the system. Moisture will
damage the system if it is not removed daily.There are two ways to do this. One is automatic
through the air brake vehicle’s air dryer with integral
automatic moisture ejector that purges air from the
system through a self-contained reservoir. The
other way to drain moisture from the air brake
system is to manually activate drain valves at each
reservoir. Drain the air reservoirs occasionally to be
sure the air dryer is working properly.
Drain the air brakes at full system pressure. To be
sure you are at full pressure, check the air pressure
gage. It should read at least 100 psi (692 kPa).
Air Dryer
If your vehicle has air brakes, it has an air dryer
mounted on the passenger side frame rail. This
collects and removes dirt, moisture, or other foreign
matter from the air prior to entering the brake
system. The dryer also acts as a moisture ejector.
It automatically ejects the moisture when the
compressor cycles. The purge tank has a manual
drain valve that must be drained every day. See
“Air Brake Systems” for the manual drain procedure.
The dryer has a filter that you need to change at
intervals. SeeScheduled Maintenance on page 363
for more about servicing this filter.
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Electric Air Compressor
Your vehicle may have an electric air compressor.
This compressor is used to run options that
require pressurized air, such as an air horn, air
seat, 7.8L engine exhaust restrictor, or 7.8L engine
exhaust brake.
The air compressor is used when vehicles do not
have an air brake system.
The air supply for
this system must be
maintained by releasing
the drain valve to eject
any moisture that
may have built up in
the system.
It is recommended that this system be drained on
a weekly basis.
Clutch Pedal Free Travel
If you have a V8 engine and a manual
transmission, the clutch will need adjustment
when pedal free travel gets down to about 1/4 inch
(6 mm), as measured at the clutch pedal pad.
You should have 1 1/2 to 2 inches (38 to 51 mm)
of clutch pedal free travel.
If the clutch ever needs service, be sure to use
only GM clutch replacement parts.
Chassis Lubrication
Your Maintenance Schedule provides all of the
required chassis lubrication intervals and identifies
proper lubricants to use. Be sure to see the
Maintenance Schedule before performing any
chassis lubrication service. To determine location of
chassis lubrication items, use the following charts.
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Single Axle Models
Item Number Item Remarks
1 Brake Camshaft** One fitting each (apply sparingly).
2 Steering Column Slip Joint* One fitting.
3 Steering Drag Link Ends One fitting each end.
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Item Number Item Remarks
4 Pivot Points and Hinges Apply chassis lubricant.
5 Pivot Points and Hinges Apply chassis lubricant.
6 Slack Adjuster** One fitting.
7Brake Cam Roller Pins at interface of pin
and shoe**Apply engine oil.
8 Front Steering KnucklesOne fitting each side, lower bushing.
(Hand-operated grease gun only.) Hand-pack
upper bearing.
9 Front Wheel Bearings Hand-pack or lubricate.
10 Steering Tie Rod Ends One fitting each end.
11 Spring Slip Pads* (Multi-Leaf Only) Apply chassis lubricant.
12 Clutch Release Bearing* Cup or fitting.
13 Battery Terminal (except “ST” type) Keep coated with petroleum jelly.
14 Transmission Fill to level of filler plug.
15 Propshaft U-JointsLubricate with GM Part No. 1051344 Wheel
Bearing Lubricant.
16 Parking Brake Clevis Pin$ Apply chassis lubricant.
17 Parking Brake Lever Pivot*, $ Apply chassis lubricant.
18Clutch Release Cross Shaft, Master
Cylinder$Apply chassis lubricant, fill to 1/4 inch (6 mm)
below opening.
19 Release Bearing, Clutch Cross Shaft Two fittings, apply chassis lubricant.
20 Clutch Release Fork Two fittings.
* Applies to some vehicles.
** Applies to air brakes only.
$ Applies to hydraulic brakes only.
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Tandem Axle ModelsItem
Number Item Remarks
1 Brake Camshafts One fitting each.
2 Propshaft U-JointOne fitting each
joint. Lubricate
with GM Part
No. 1051344, Wheel
Bearing Lubricant
3 Rear AxlesFill to level of
filler plug.
4Brake Shoe
Roller PinsApply engine oil
at pin to shoe joint
only.
5 Rear Spring PinOne fitting
each side.
Battery
Your vehicle has one or more maintenance free
batteries. When it is time for a new battery, be sure
it has the replacement number shown on the
original battery’s label. We recommend an
ACDelco
®replacement battery.
Warning:Battery posts, terminals, and related
accessories contain lead and lead compounds,
chemicals known to the State of California
to cause cancer and reproductive harm. Wash
hands after handling.
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