Mechanics

BRAKE QUESTION -- K3500 DUALLY

1990 Chevrolet Silverado • V8 4WD Manual • 130,000 miles

When pushing on the brakes, the rear brakes are more aggressive than the front brakes. It gets real interesting when it is slick out as the back breaks lock-up and there is limited front brakes.

These are hydraulic assist brakes that came in these things.

Brakes are new this summer, front calipers are new also. Issue was present before replacement. There are no liquids on the drums or pads. Bled the front brakes.

There is a ABS control module and ABS Hydraulic Unit, I don't know if there is a proportioning valve in this or not.

Any help on ideas on what this could be would be great.
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Mb12868
January 17, 2011.



That really sounds like brake contamination. You don't have to actually see any liquid. Even very small amounts will embed into the shoes along with brake dust and ruin the shoes and the drum surface. If the shoes look dark in color at all, then they are likely contaminated. Look at the backing plate carefully for any apparent dark spots to indicate oil residue from either the brake fluid in the wheel cylinders or gear oil from the differential seals.

Wrenchtech
Jan 17, 2011.