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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
helps keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of uid in the brake
hydraulic system, the brakes might not work
well. This could cause a crash. Always use the
proper brake uid.Notice:
Using the wrong uid can badly damage brake
hydraulic system parts. For example, just a
few drops of mineral-based oil, such as engine
oil, in the brake hydraulic system can damage
brake hydraulic 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 5-97.
Four-Wheel Disc Brakes
(Hydraulic Only)
Your vehicle has four-wheel disc brakes.
Some driving conditions or climates can 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.
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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/retailer 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
might be required.
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.
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 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
replacement parts. If you do not, the brakes might not
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.
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Hydraulic Brake Pads
Brake pad lining life will vary depending on vehicle
application, working environment, equipment
maintenance, and style of driving. The brake pad lining
wear rate has to be monitored for individual driving
habits — original equipment linings have mechanical
wear indicators to help with this. When you are down to
the last 10% of the brake lining, the brake lining wear
indicator will rub on the rotor, causing a scratching or
chirping sound. When you hear this sound, it is time to
service the brake pads. SeeScheduled Maintenance on
page 6-5.
Aftermarket brake linings might not meet the same
stringent requirements as the original equipment linings.
Using aftermarket brake linings can affect braking
performance, pedal feel, noise, and lining wear.
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 6-5for
more about servicing this filter.
Electric Air Compressor
Your vehicle might have an electric air compressor. This
compressor is used to run options that require
pressurized air, such as an air horn or air seat.
The air compressor is used when vehicles do not have
an air brake system.
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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.
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.
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Item Number Item Remarks
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.
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Jump Starting
If your vehicle’s battery (or batteries) has run down, you
may want to use another vehicle and some jumper
cables to start your vehicle. Be sure to use the following
steps to do it safely.
{CAUTION:
Batteries can hurt you. They can be dangerous
because:
They contain acid that can burn you.
They contain gas that can explode or
ignite.
They contain enough electricity to
burn you.
If you do not follow these steps exactly, some
or all of these things can hurt you.
Notice:Ignoring these steps could result in costly
damage to your vehicle that would not be covered
by your warranty.Trying to start your vehicle by pushing or pulling it
will not work, and it could damage your vehicle.
1. Check the other vehicle. It must have a 12-volt
battery (or batteries) with a negative ground system.
Notice:If the other vehicle’s system is not a 12-volt
system with a negative ground, both vehicles can
be damaged. Only use vehicles with 12-volt systems
with negative grounds to jump start your vehicle.
If you have a diesel engine vehicle with
two batteries (or more), you should know before
you begin that, especially in cold weather, you may
not be able to get enough power from a single
battery in another vehicle to start your diesel engine.
If your vehicle has more than one battery, use the
one closest to the starter — this will reduce electrical
resistance.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles are not touching
each other. If they are, it could cause a ground
connection you do not want. You would not be able
to start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake firmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake.
If you have a four-wheel-drive vehicle, be sure the
transfer case is in a drive gear, not in NEUTRAL.
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