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