Hummer H2. Manual — part 83

VACUUM BOOSTERS

Vacuum Boosters

Alignment incorrect

B

Require repair or replacement.

Bent

B

Require replacement.

Contaminated, affecting performance

A

Require repair. Identify and correct cause.

Cracked

B

Require replacement.

Loose

A

Require replacement of worn parts.

Missing

C

Require replacement.

Number of teeth incorrect

B

Require replacement.

Teeth broken

A

Require replacement.

Teeth damaged, affecting performance

A

Require replacement.

Condition

Code

Procedure

Applies too much assist (oversensitive)

A

Require replacement.

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.

Auxiliary vacuum pump inoperative

A

Require repair or replacement. See

note below.

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

Check valve grommet deteriorated, affecting
performance

A

Require replacement of grommet.

Check valve grommet deteriorated, not
affecting performance

1

Suggest replacement of grommet.

Check valve inoperative

A

Require repair or replacement. See

note below.

NOTE: Inoperative includes intermittent operation.

Check valve leaking

A

Require replacement of check

valve.

Check valve missing

C

Require replacement of check

valve.

Check valve noisy

2

Suggest replacement.

Connector broken

A

Require repair or replacement.

Connector (Weatherpack type) leaking

A

Require repair or replacement.

Connector melted

A

Require replacement. See note

below.

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

Connector missing

C

Require replacement.

1998 Chevrolet Pickup C1500

Uniform Inspection and Communication Standards BRAKE SYSTEMS

VACUUM HOSES

See Hoses.

VALVES

Valves

Leaking

A

Require 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.

Threads damaged

A

Require repair or replacement.

Threads stripped (threads missing)

A

Require replacement.

Vacuum hose filter leaking

A

Require replacement of filter.

Vacuum hose filter restricted

A

Require replacement of filter.

Wire lead burned

A

Require repair or replacement.

Wire lead conductors exposed

B

Require repair or replacement.

Wire lead open

A

Require repair or replacement.

Wire lead shorted

A

Require repair or replacement.

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.

Leaking

B

Require repair or replacement.

Linkage bent (rear load valves)

A

Require repair or replacement of linkage.

Linkage broken (rear load valves)

A

Require repair or replacement of linkage.

Linkage disconnected (rear load
valves)

C

Require repair or replacement of linkage.

Pressure out of specification

B

Require adjustment. If not possible, require

replacement.

Seized

A

Require replacement.

Sticking

A

Require repair or replacement.

Terminal burned, affecting
performance

A

Require repair or replacement. See note

below.

1998 Chevrolet Pickup C1500

Uniform Inspection and Communication Standards BRAKE SYSTEMS

WHEEL ATTACHING HARDWARE

For conditions noted below, also check condition of wheel stud holes.

Wheel Attaching Hardware

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.

Threads damaged

A

Require repair or replacement.

Threads stripped (threads missing)

A

Require replacement.

Wire lead burned

A

Require repair or replacement.

Wire lead conductors exposed

B

Require repair or replacement.

Wire lead open

A

Require repair or replacement.

Wire lead shorted

A

Require repair or replacement.

CAUTION: Proper lug nut torque is essential. Follow manufacturer's torque

specifications and tightening sequence. DO NOT lubricate threads unless
specified by the vehicle manufacturer.

Condition

Code

Procedure

Bent

A

Require replacement.

Broken

A

Require replacement. See note below.

NOTE: Some manufacturers require replacement of all studs on any wheel if two or
more studs or nuts on the same wheel are broken or missing.

Loose

B

Require repair or replacement of affected

component.

Lug nut flats rounded

A

Require replacement of nut.

Lug nut installed backward

B

Require repair.

Lug nut mating surface
dished

A

Require replacement of nut.

Lug nut mating type
incorrect

B

Require replacement of nut.

Lug nut seized

A

Require replacement of nut and/or stud.

1998 Chevrolet Pickup C1500

Uniform Inspection and Communication Standards BRAKE SYSTEMS

WHEEL BEARINGS, RACES, AND SEALS

Wheel Bearings, Races, and Seals

WHEEL CYLINDERS

You are not required to replace or rebuild wheel cylinders in axle sets. However, when rebuilding or replacing a
wheel cylinder due to the conditions that follow, you may suggest rebuilding or replacement of the other wheel
cylinder (on the same axle) for preventive maintenance, for example, the part is close to the end of its useful
life.

Determine the need to rebuild or replace based upon the individual wheel cylinder conditions that follow.

Wheel Cylinders

Stud incorrect

B

Require replacement of stud.

Threads damaged

A

Require repair or replacement of component with

damaged threads.

Threads stripped (threads
missing)

A

Require replacement of component with stripped

threads.

NOTE:

When replacing or repacking wheel bearings, grease seal replacement is
required . You are not required to replace these components in axle sets.
Determine the need to replace based upon the individual component conditions
that follow.

Condition

Code

Procedure

Axle seal on drive axle leaking

A

Require replacement of seal and inspection of

axle, bearing, housing, and vent tube.

Bearing end-play exceeds
specifications

B

Require adjustment of bearing, if possible. If

proper adjustment cannot be obtained, require

replacement of bearing and race assembly.

Bearing rollers, balls or races are
worn, pitted, or feel rough when
rotated as an assembly

B

Require replacement of bearing and race

assembly.

Seal leaking

A

Require replacement of seal and inspection of

bearings. See note below.

NOTE: Require inspection of mating and sealing surface and repair or replace as
necessary. Check vent. A plugged vent may force fluid past the seal.

Seal missing

C

Require replacement.

Spindle worn

B

Require replacement of spindle and bearings.

Condition

Code

Procedure

Attaching hardware bent

B

Require replacement of bent parts.

Attaching hardware broken

A

Require repair or replacement of hardware.

1998 Chevrolet Pickup C1500

Uniform Inspection and Communication Standards BRAKE SYSTEMS