I have a 1987 S-15 pickup which has had a problem for quite a while with the rear brakes locking whenever it's cold or cold and damp out. Until the brakes warm up, you can't touch them soft enough to prevent locking. Even the lightest touch and the rears lock dead up. I have to drive down our road with one foot on the gas and the other lightly on the brake to warm them up in the morning. Above 50 degrees and they're perfectly fine. The brakes have been serviced twice since having this problem with new pads and such. Any ideas? Can a proportioning valve have problems only at low temperatures?

 

New brake lines perhaps?

 

How do you feel the brake lines would cause that?

 

I'm not a brake expert or anything but my suggestion is to just take it to a brake shop and have them look at it. It could be your caliper messing too....they should be able to help you out (I hope). Like I said, I'm not an expert, I'm just trying to give some suggestions. Sorry.

 

I'm sorry, there was no offense- I was just wondering what your specific thought was.

 

Don't worry about it. No offense taken, no defense given. [sm=icon_cheers.gif] Hope you get the problem solved.

 

Had a similar problem on an old ford pick up I had. Turned out to be a bad caliber. Hope this helps

 

GM hoses of that age are famous for breaking down internally causing many dfferent issues. I had a fullsize truck with same problem and 2 new hoses at 16 a pc solved it good luck

 

Do you have disk or drum brakes? If it is drum brakes I would replace the wheel cylinders and flush the brake fluid at the same time.