All four brakes are locking up.

[grayduty]

Okay so here's the problem I'm having with my 2002 f250 4x4 diesel. I can drive approximately 4 miles before all 4 of my brakes start locking up to about 50%. I did the Haynes check for the hydro boost before and after the problem (before I drove my truck and after I drove it and made the brakes lock up). And it checked out fine. And when the brakes lock up the pedal gets rock hard.

I just recently got the recall done (the cruise control brake valve or something.) and I called ford and got a typical response saying "that wouldn't cause any of those problems." which I don't believe. And the only other things that change before the problem started was the recal and new power steering pump and gear box.

Please help. I need my truck back up and running tomorrow. Please any help will be good. Thanks in advance.

[grayduty]

Really?? Nobody at all has anything? I can hardly believe that this has only happened to me.

Anyways. I have done everything that I can think of except selling the truck. I have new skyjacker extended brake lines for the front since I've narrowed the problem down to the front right wheel. I took the brand new caliper back to AAP and got another new one. I have bled all the brakes 6 times all together. And after I bleed them they work like normal for about a day and a half.

I'm out of ideas. Would someone please help me?

[forddieseldoctor]

Wow I don't know what to tell you. Um... when it goes tight can you crack the bleeder on the rf wheel and then it goes back to normal?

And btw the recall is only a jumper harness on the cruise deactivation switch on the master cylinder. It has nothing to do with the brakes other than it reads pressure.

[grayduty]

Thank you for the reply. Yeah when I get it home and get it jack up the wheel is locked. Crack the bleeder and it spins all day. And about the recall. I wasn't completely listening when I was told what it was for. So I apologize.

[forddieseldoctor]

If you are cracking the bleeder and it goes away than that says to me that you have a restriction in a line or a hose. You need to get it to lock up again and crack the line at the top of the hose and work your way back to the abs module and then to the master cylinder. When you find the spot where it releases on one end but not on the other then you know where the restriction is. If you pump the brakes does that wheel stay locked up after you release the pedal?

[jesilvas]

Well if you weren't listening about the recall don't say they're lying to you.
There might be an ABS sensor issue?

[grayduty]

It's not that quick to lock up. I can drive about 6-10 miles before it'll lock up after it sits at night. I haven't tried that line cracking method yet I'll try it in the morning.

[897.3alltheway!]

maybe its a valve the brakes run to

proportion valve? if its on there

my 89 recently made a grinding noise and wanted to lock up the driver rear tire with drum brakes

[xjeeper]

I had a brake pushrod that was too long for the master cyl cause a similar problem on a jeep, it would not fully release the brakes when hot and pressure would build until they draged. a slight grind on the brake pushrod cured it on the jeep, maybe aproblem with the hydroboost mster cyl compatability? We diagnosed it by loosening the master cyl bolts to let the brakes release fully.

[grayduty]

The brakes all worked great before I changed everything on the brakes (except the rotors were shot and same with the pads. The slide pins were even seized up and they worked flawlessly.) so I don't think it'd be the push rod. And I even flushed the PS system thinking that it was something in the hydroboost. It didn't help any. Do you think a brake fluid flush would be a benefit? How much is one? Can I do it my self or is special tools necessary? And if you noticed I'm clueless about the braking system. It's my kryptonite.