Colorado 4WD L5-3.7L (2007)
Brake Drum: Customer Interest
Brakes - Brake Drag/Grab/Rear Brakes Lock Up
TECHNICAL
Bulletin No.: 07-05-24-001B
Date: February 25, 2008
Subject:
EI07051 - Excessive Brake Grab, Aggressive Drag, Lock Rear Brakes Drums and Shoes (Remove High Spots from Drum Surface Finish)
Models:
2005-2008 Chevrolet Colorado
2005-2008 GMC Canyon
Supercede:
This bulletin is being updated to add model years and additional information. Please discard Corporate Bulletin Number 07-05-24-001A (Section 05 -
Brakes).
Condition
Some customers may comment that after the vehicle has set for a while, during the first few stops, it will feel like the brakes are grabbing excessively. In
addition, the tires may chirp and/or leave skid marks during braking.
Cause
This condition may be caused by a mirror-like finish between the drum and the brake shoe.
Correction
Remove the rear drums and inspect the rear axle seals and wheel cylinders for leaks. Inspect the brake shoes for contamination. If no leaks are found,
perform the following:
Important:
Only replace the rear brake shoes if a leak is found and the shoes have been contaminated with fluid from the rear axle or wheel cylinder.
1.
Machine both rear drums to eliminate high spots.
2.
For the left side, replace the drum brake star wheel adjuster with P/N 19133371. This adjuster is a 15-tooth adjuster. Refer to Adjusting Drum
Brakes in SI.
Important:
Take care to grind off every other tooth as shown above.
Important:
P/N 19133371 is threaded for the left side only. DO NOT attempt to install the adjuster (P/N 19133371) on the right side of the vehicle.
3.
For the right side, grind off every other tooth of the star wheel adjuster. Use suitable dremel and cut-off wheel (preferably a 1-1/4 in X 1/16 ).
4.
Reinstall the adjuster and adjust the brake shoes accordingly. Refer to SI for adjusting brake shoes.
