Bad Brake Proportioning Valve???

[zipgun]

Hi all,

My 90 Burb has been front braking really weird. I have never had a prop valve die on me so here goes. When the brakes are cool and during the first stops it does fine but after they are used awhile the front end seems to grab in each direction alternating grabs. I do not believe the rotors are warped (truck has 123,000 miles on it) and from what I can tell the caliper pistons seem to be operating alright. Anyone ever deal with this or experience the same symptoms ?

Thanks all,

Steve

[dwcsr]

Front brake hoses at the steel clip where they bolt to the arm some how swell or shrink and restrict the flow when hot. had this happen on my 92. changed everything down to the bearings never thinking a hose would be the cause.

[zipgun]

Hey DWCSR Thanks !!!! You were right on the money !! No more teeth chattering stops !! Thanks I appreciate the help.

[dwcsr]

When it happened to me I was in hi speed traffic in a construction zone. Changed my shorts when i got home.

[zipgun]

Originally Posted by dwcsr

When it happened to me I was in hi speed traffic in a construction zone. Changed my shorts when i got home.

I drove from North Carolina to Washington DC for the fourth. Thing ran great until on the way back it started shuddering again. If I pump the brakes acouple times before mashing all the way down it wont shudder. Its got me stumped. Pulled into my driveway and the water pump popped the weep holes. Replaced that yesterday. I love this truck just wish i could figure out whats up with the front discs doing the boogie woogie braking.

[dwcsr]

make sure the the pads are tight in the calipers. bend the pad tabs so they are against the housing tightly. it sounds like the pads are wobbling on the calipers