brakes locking up?

[kylev90]

my brakes have always locked up as soon as I hit them when wet in the morning or after sitting for a while. Once warmed up and dried out they were fine. This time it basically never went away. Anything around 50% braking and the front end completely locks up and the truck just slides. I thought it was passenger side so i replaced that caliper but it didnt help. Any ideas? These trucks dont have a proportioning valve right?

[1Dieselman]

Yes they have a proportioning valve, straight below the master cylinder in the frame rail. Are you sure your rear brakes are working at all? Maybe the rears aren't adjusted properly causing the front to do all the work.

[kylev90]

I haven't checked yet. Even if they are way out of adjustment I didn't think it would make the fronts totally lock up. I'll check thanks for the info

[1Dieselman]

Other thing that comes to mind is what kind of front pads are you using and are the rotors smooth?

[kylev90]

ya rotors are smooth. Pads are just the advanced auto golds

[1Dieselman]

I'm not familiar with advance pads, is that organic, semi metallic, metallic, or ceramic?

[kylev90]

im almost positive they are ceramic. Do you recommend one over the other?

[1Dieselman]

I almost always use semi metallic. The metallic and ceramic pads can be really finicky if not seat exactly like the manufacture recommends. I feel that the ceramic pads should be for high speed applications.

[kylev90]

ok, rear brakes are adjusted right. I replaced the master cylinder, both calipers, pads, the rubber lines from frame rail to caliper and the ABS/speed sensor on the rear pumpkin. Brakes still locking up and getting worse. Only thing thats left is the proportioning valve right? Ford wants $480 for one. Know of anywhere else to find one?

[1Dieselman]

Holy cr*p, that's expensive. You could try a used one from ebay or car-part.com. This isn't the first time that I've heard of one being a problem but its pretty rare. Here's Napa's NAPA AUTO PARTS