Hummer H2. Manual — part 81

MODULATORS

See Hydraulic Modulators.

MOTORS

See Electrical Pumps and Motors.

PARKING BRAKE SWITCHES

See Switches.

PARKING BRAKE SYSTEMS

Parking Brake Systems

Piston does not return

A

Require repair or replacement.

Ports plugged

A

Require repair or replacement.

Rubber master cylinder cover gasket
distorted and gummy

A

Require replacement of the gasket.

See note below.

NOTE: This condition may indicate contaminated brake fluid. See Brake Fluid.

NOTE:

The parking brake is an integral part of the brake system. It is important that the
parking brake function properly when brake service is performed.

Condition

Code

Procedure

Attaching hardware broken

A

Require repair or replacement of

hardware.

Attaching hardware missing

C

Require replacement of

hardware.

Attaching hardware not functioning

A

Require repair or replacement of

hardware.

Cable improperly adjusted

B

Require cable adjustment.

Cable or individual wires in the cable are broken A

Require replacement of cable

assembly.

Cable sticking

A

Require cable lubrication.

Cable stuck inside conduit and cannot be
lubricated so that parking brake functions
properly

A

Require replacement of cable

assembly.

Inoperative

A

Require replacement of

inoperative parts. See note

below.

NOTE: Inoperative includes intermittent operation.

1998 Chevrolet Pickup C1500

Uniform Inspection and Communication Standards BRAKE SYSTEMS

PADS

See Friction Material.

PEDAL TRAVEL SWITCHES

See Switches.

PEDALS

See Brake Pedals.

POWERMASTER

See Hydro-Boosters.

PUMPS

See Electrical Pumps and Motors.

PRESSURE DIFFERENTIAL SWITCHES

See Switches.

PRESSURE SWITCHES

See Switches.

RELAYS

Relays

Parking brake parts bent

B

Require repair or replacement of

bent parts.

Parking brake parts broken

A

Require replacement of broken

parts.

Parking brake parts missing

C

Require replacement of missing

parts.

Threads damaged

A

Require repair or replacement.

Threads stripped (threads missing)

A

Require replacement.

Condition

Code

Procedure

Attaching hardware broken

A

Require repair or replacement of

hardware.

1998 Chevrolet Pickup C1500

Uniform Inspection and Communication Standards BRAKE SYSTEMS

ROTORS

Determine the need to recondition based upon individual rotor conditions that follow. Friction material
replacement does not require rotor reconditioning unless other justifications exist. Do not recondition new
rotors unless they are being pressed or bolted onto an existing hub. It is not necessary to replace rotors in axle
sets. However, when replacing or reconditioning a rotor due to the conditions that follow, you may suggest
reconditioning of the other rotor on the same axle to eliminate uneven braking behavior.

Determine the need to replace based upon the individual rotor conditions that follow. Reconditioning is defined
as machining and block sanding, or block sanding only. Block sanding is defined as using 120-150 grit
sandpaper with moderate to heavy force for 60 seconds per side. Always wash rotors after servicing or before
installing.

Rotors

Attaching hardware missing

C

Require replacement of hardware.

Attaching hardware not functioning

A

Require repair or replacement of

hardware.

Housing broken

A

Require replacement.

Housing cracked

2

Suggest replacement.

Inoperative

A

Require replacement. See note below.

NOTE: Inoperative includes intermittent operation or out of OEM specification.

Missing

C

Require replacement.

Terminal broken

A

Require repair or replacement.

Terminal burned, affecting performance

A

Require repair or replacement. See note

below.

NOTE: Determine cause and correct prior to repair or replacement of part.

Terminal burned, not affecting
performance

2

Suggest repair or replacement.

Terminal corroded, affecting
performance

A

Require repair or replacement.

Terminal corroded, not affecting
performance

2

Suggest repair or replacement.

Terminal loose, affecting performance

B

Require repair or replacement.

Terminal loose, not affecting
performance

1

Suggest repair or replacement.

Condition

Code

Procedure

Corrosion affecting structural integrity

A

Require replacement. See note

below.

NOTE: Examples of severe corrosion are: composite plate separated from friction
surfaces and cooling fins cracked or missing.

Cracked

B

Require replacement.

1998 Chevrolet Pickup C1500

Uniform Inspection and Communication Standards BRAKE SYSTEMS

SELF-ADJUSTING SYSTEMS

Self-Adjusting Systems

Hard spots

2

Suggest reconditioning or

replacement of rotor according to

OEM specifications.

Lateral runout (wobble) exceeds OEM
specifications

B

Require re-indexing,

reconditioning, or replacement

according to specifications.

Measured thickness is less than OEM discard
specifications

B

Require replacement.

Rotor thickness is less than OEM "machine to"
specifications but thicker than "discard at"
specifications, and the rotor does not require
reconditioning

1

Suggest replacement. See note

below.

NOTE: Only applies to vehicles for which OEM "machine to" specifications exist. If
OEM does not supply "machine to" specifications, the rotor may be worn to discard
specifications.

Rotor thickness will be less than OEM
"machine to" specifications after required
reconditioning

B

Require replacement. See note

below.

NOTE: If OEM does not supply "machine to" specifications, you may machine to
discard specifications.

Surface is rust-pitted

B

Require reconditioning or

replacement of rotor according to

OEM specifications.

Surface is scored

B

Require reconditioning or

replacement of rotor according to

OEM specifications. See note

below.

NOTE: Scoring is defined as grooves or ridges in the friction contact surface. Some
vehicle manufacturers require machining when scoring exceeds their allowable
specifications.

Thickness variation (parallelism) exceeds
OEM specifications

B

Require reconditioning or

replacement of rotor according to

OEM specifications.

Condition

Code

Procedure

Bent

A

Require repair or replacement of bent part.

Broken

A

Require repair or replacement of broken part.

Inoperative

A

Require repair or replacement of inoperative parts. See

note below.

NOTE: Inoperative includes intermittent operation.

1998 Chevrolet Pickup C1500

Uniform Inspection and Communication Standards BRAKE SYSTEMS