1996 Yukon Brake issues

[stuss22]

I have a 1996 GMC Yukon 5.7ltr. It has 275,000 miles.

When I first get in the yukon in the morning and drive off, I get to the first stop and my brake pedal feels normal, but they grab and about throw into the windshield if I did'nt have my seat belt on.
This will do this until they get warmed up and seem to operate OK. The next day is the same grabbing.

I've had new rear brake including new drums, and front brakes including rotors and fluid flush. I can't figure this one out.

Any help out there?

[stuss22]

bump

[maxwedge]

Wow, 9 months later we are still going here? This usually caused by moisture on the rear shoes/lining causing a brake grab when first used. I beleive there may be an updated lining from GM for this issue.

[stuss22]

I have heard that the 97's were sensitive to factory brake shoes? I have had the rear brakes gone through a independent brake shop, and still have the same grab problem. This issue has been going on for quite sometime. My yukon has 286,000 miles on it and I have gone through all the brakes, but haven't replaced brake lines or master cylinder. Could one of those be causing the problem?

This vehicle does sit alot between driving now.

Thanks

[maxwedge]

More than likely if the rear shoes are the newer style, the proportioning valve is next.