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Checking Brake Fluid (Hydro Max System)
Apply the brake pedal several times with the ignition
off. Then 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.
The Hydro Max brake fluid
reservoir is located in the
engine compartment
on the driver’s side of the
vehicle.
If it is low, add enough fluid to fill the reservoir to the
proper level.
Checking Brake Fluid (Hydro Boost
System)
Apply the brake pedal several times with the ignition off.
Clean the cover and the side of the reservoir. Check
to see if the fluid level inside the reservoir falls within the
MIN/MAX level indicator on the side of the reservoir.
The Hydro Boost brake
fluid reservoir is located in
the engine compartment
on the driver’s side of
the vehicle.
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 your 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 your brake
system, your 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 your
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. SeeAppearance
Care on page 5-76.
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Page 255 of 366

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
your 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 of brake trouble.
Brake Adjustment
Every time you make a brake stop, your brakes adjust
for wear.
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 your braking
system — for example, when your brake linings
wear down and you need new ones put in — be sure
you get new approved GM replacement parts. If you do
not, your brakes may no longer work properly. For
example, if someone puts in brake linings that are wrong
for your vehicle, the balance between your 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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Air Brake Systems
If your vehicle has air brakes, it is important to get rid of
moisture in your system. Moisture will damage your
system if it is not removed daily.
There are two ways to do this. One is automatic if your
air-brake vehicle has the optional moisture ejector. If
your vehicle does not have that option, you must 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 your air pressure
gage. It should read at least 100 psi (692 kPa).
Moisture Ejector
If you have air brakes with a moisture ejector, the valve
automatically ejects moisture from the reserve tank
when the air compressor cycles.
Air Dryer
If your vehicle has air brakes, it may have an air dryer.
This collects and removes dirt, moisture or other
foreign matter from the air prior to entering the brake
system. It is mounted on the passenger’s side frame rail.
If your dryer is a Bendix-Westinghouse, it has a filter
that you need to change at intervals. SeeScheduled
Maintenance on page 6-5for 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 air horn, air seat, exhaust
restrictor or an exhaust brake.
The air compressor is used when vehicles are not
equipped with 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 manual transmission, your clutch will need
adjustment when pedal free travel gets down to about
1/4 inch (32 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. SeeScheduled Maintenance on
page 6-5for more information.
If your 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 your Maintenance
Schedule before performing any chassis lubrication
service. To determine location of chassis lubrication
items, use the following charts.
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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.
15 Propshaft Slip 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.
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Item Number Item Remarks
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.
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 battery (or batteries) has run down, you may
want to use another vehicle and some jumper cables to
start your vehicle. Be sure to follow the steps below
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 aren’t touching
each other. If they are, it could cause a ground
connection you don’t want. You wouldn’t 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.
Notice:If you leave your radio or other accessories
on during the jump starting procedure, they could
be damaged. The repairs would not be covered
by your warranty. Always turn off your radio and
other accessories when jump starting your vehicle.
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