Workshop Repair and Service Manuals GMC SIERRA

00-05-22-002N Disc Brake Warranty Service and Procedures - (May 31 2013) Disc Brakes - part 11

Squeak/Squeal Noise:Occurs with front semi-metallic brake pads at medium speeds when light to medium pressureis applied to the brake pedal.Occasionally a noise may occur on rear brakes during the first few stops or with coldbrakes and/or high humidity.Grinding Noise:Common to rear brakes and some front disc brakes during initial stops after the vehiclehas been parked overnight.Caused by corrosion on the metal surfaces during vehicle non-use. Usually disappearsafter a few stops.

Groan Noise:

A groan type noise may be heard when stopping quickly or moving forward slowly froma complete stop. This is normal. On vehicles equipped with ABS, a groan or moan typenoise during hard braking applications or loose gravel, wet or icy road conditionsis a normal function of the ABS activation.

KEY POINTS — FREQUENTLY ASKED QUESTIONSQ: How do on-car lathes react to Axle Float- Does the play affect the machining of therotor, either surface finish or LRO-

A: Because the Pro-Cut on-car lathe adjusts in a live mode while spinning the hub/rotor,the dynamics of a floating axle are effectively eliminated. Once the lathe is compensated,there is no difference in the cutting/surface finish and LRO arejust the same as with a non-floating axle.

Q: Which lathe is essential for performing brake work, the bench or on-car-

A: Dealers must have a well maintained bench lathe and well maintained on-car lathe.These lathes need to be calibrated on a monthly basis. BOTH lathes are essential toproviding quality brake service.

Q: What is the expected tip life for an on-car lathe-

A: The geometry and composition of the Pro-Cut tips are designed for “single pass” cutting.When using the Pro-Cut the cutting depth should be set to take all material neededto get below rust grooves, eliminate all run-out and resurface the entire disc ina single pass. Cuts of 0.1016-0.381-mm (0.004-0.015-in)will provide the best surface finish and the optimal tip life. No “skim cut” or “finishcut” is needed. Failure to follow this procedure will shorten tip life. The Pro-cuttips will last between 7-12 cuts per corner. With three usable corners, a pair oftips is good for at least 21 cuts.

Q: Why does GM recommend the use of single pass (referred to as “positive rake”) benchand on-car brake lathes-

A: GM Service and GM Brake Engineering have performed competitive evaluations on a significantnumber of bench and on-car brake lathes. These tests measured critical performancecharacteristics such as flatness, surface finish and the ability of the latheto repeat accuracy over many uses. In each test, single pass lathe designs out performedthe competitors. Single pass brake lathes are more productive requiring less timeto perform the same procedure.

Q: Is it okay to leave the caliper/pads installed while cutting rotors using an on-carlathe-

A: On-car lathes should never be used with the pads and calipers installed on the vehicle.The debris from cutting the rotors can contaminate the brake pads/calipers which canlead to other brake concerns and comebacks.

Brake Fluid Level Indicator Switch Replacement (Two-mode Hybrid)     Brake Fluid Level Indicator Switch Replacement Callout Component Name Preliminary ProceduresPlace the ignition switch in the OFF position.Disconnect the brake fluid level sensor electricalconnector. 1 Brake...
PIT4593D 2-MODE (HYBRID) No Brake Assist After Low 12V Battery Power or 12V Disconnect - (Nov 15 2012)     Subject: 2-MODE (HYBRID) No Brake Assist After Low 12V Battery Power or 12V Disconnect Models:  2009-2013 Cadillac Escalade Hybrid 2008-2013 Chevrolet Tahoe and GMC Yukon Hybrid 2009-2013 Chevrolet Silverado...
Brake Pedal Travel Measurement and Inspection (Two-mode Hybrid) Hydraulic Brakes Brake Pedal Assembly     Note:The brake corners must be cool to obtain the most accuratemeasurement. Place the transmission in PARK. Note:The ignition must be OFF, without pausing at ACCESSORY, andwithout applying the brake pedal to ensure the brake...
Parking Brake Actuator Replacement (JD9) Parking Brake Lever or Pedal     Parking Brake Actuator Replacement Callout Component Name Warning:Refer toBrake Dust Warning. Preliminary ProceduresDisable the park brake cable automatic adjuster. Refer toParking Brake Cable Adjuster...
Front Brake Caliper Hardware Replacement (J90 J95 J96) Disc Brakes Brake Calipers     Removal Procedure Warning:Refer toBrake Dust Warning. Remove the brake caliper bracket. Refer toFront Brake Caliper Bracket Replacement. Remove the brake caliper guide pinseals-(1).Remove the brake caliper guide...
Fastener Tightening Specifications - 4WD Driveline Control Parking Brake     Fastener Tightening Specifications Application Specification Metric English Parking Brake Cable Guide Bolt 12-Y 106-lb-in Parking Brake Indicator Switch Bolt 3-Y 27-lb-in Parking Brake...