1997 GMC Sierra Brakes Shaking Truck

MRFIXIT820

MEMBER
1997 GMC SIERRA
V8
2WD
AUTOMATIC
298,000 MILES

When I use my brakes, my truck shakes violently. When I first start out in the morning, the first couple of times I use my brakes there is little or no shaking, after that it comes back with a vengence. I replaced the front brake pads, calipers and wheel bearings. I also had the rotors turned (they told me the rotors were in good shape and needed very little turning). Everything got better for about a month and then the shaking came back. What else could cause this or what could I be doing wrong? Air in the lines? Master cylinder? I am at a loss. Also the rear brakes look good and are adjusted properly.

1 Reply

MHPAUTOS

MECHANIC
31,937 POSTS

Hi there,

Bad body vibration under braking can be caused by a rear drum out of round, larger brake drums require specialized turning to ensure they are true. I would be looking at the rear brakes. A simply way of testing the rear brakes is to find a quiet straight stretch of road, use a brake hose clamp and lock off the rear flexi brake hose, drive and test brakes, if no vibration you have found your problem, be careful as the brakes will be that much less efficient with the backs off line, don't drive like this in traffic.

Mark (mhpautos)