Hey guys, Back again with another issue that needs to be solved with the fellow guys. I Have a 1993 F150 2WD With the 5.0L 302 Motor. It has 216700.6Mi on it, and I just recently, actually yesterday, Replaced my master Cylinder and Flushed my brake system by gravity.(leaving the truck on the lift while the air slowly lets out) Just to take up my time while I'm at school. when I come back and its finally Flushing clean fluid through the whole system, I closed all the bleeder screws back up and made sure everything was fine. I let the truck down and went to back out, and for some reason one of my rear brakes were locked up. I believe it's on the Drivers side. My Parking brake was on when I put it on the life. I understand I don't need to use it on the lift but I did out of habbit. The parking brake was off when I tried backing out. I don't know what the problem is for sure. i know that the bleeder screw on that side was clogged but i had unclogged it before bleeding the whole system. It's locked up to the point to where i could get out of the truck and the whole thing just not move while its in drive or reverse. Now for the weird part. I had to take it home, since I can't afford a tow truck and it's my only way to get to school and back. babying it up to 45-50. Then it just magically stops grabbing it. But when I come back to a complete stop and put it in park, and try to go again, it locks up again. I First thought it could be the Pushrod on the brake booster pushing on the master cylinder just enough to where it will lock engage the brakes, and I've been hearing about Something dealing with the parking brake getting bound up and good stuff like that. Any oppinions and suggestions anyone? All Will Be Appreciated. Thank you for your time and sorry for the whole long selection, I wanted to make everything as strait forward as possible. Thanks again, Jason Voliva

 

Readjust that drum manually.

John

 

The regular brakes are fluid driven...The E-Brakes are cable driven...

Have a friend to push the brake pedal in, as you look along the cables on the drivers side frame rail...Look for binding, etc....

Pull the drums off the wheel....See if there's anything obvious goin on...

 

I had this issue and it was costly to me. Going off the PO he told me that master and left front was all new parts from a ASE service center. I went and replaced EVERYTHING rubber and steel lines included. It was the rod on the master it was adjustable and out just a bit too far. Mine affected the fronts more then the rear. Dont rule it out just yet. Seeing you just did the master and this happened Id think its a good place to start. You dont have to pull the lines to check this so it should be fast to do. Measure twice and dont forget that that master does not bottom out in the bore IE: Measure to the flange and subtract for the booster hole depth. This is how I over looked it the first time.... Stupid math can be so smart... LOL Anyways, good luck.

 

I've Already adjusted the pushrod in the brake booster and it's still doing it. There's got to be somthing with the wheel cylenders not releasing any pressure? because the pressure of the brake fluid goes in, and it's supposed to return and it's not. So I'm sure theres something dealing with that. Yes I do understand that the E-Brake is driven by a cable i've known that for a while, the reason i mentioned it is because it could've been a possibility. I just wanted to see if anyone else had experienced the problem with the ebrake before to see what i should look out for, but knowing now that the pressure in the brake lines is not returning to the master cylinder is mind boggling to me at the moment. It could be a couple things. If it is the fluid in the lines not returning it could be a blockage somewhere in the line, but you'd think all 140 something PSI would push the blockage out and or not go through at all. So im guessing right now it has to do something with the rear inside the drum. People have told me that the wheel cylinder could be leaking, but if the wheel cylinder was leaking i would have loss of brake pressure all around reason being is that brake systems are in constant pressure all around. When we hit the bleeder screw while pumped down on the brakes, we heard a loud bang and everything come loose. believe it or not i thought everything was fixed. but when returned home and put it in park, i came back out to go off to work, the brakes were locked up again. i had no choice but to drive it to work being it's my only transportation, and slowly gets better, somehow pressure is getting released back into the master cylinder slowly only when im driving or it sits for a long time.

 

When its locked, crack the bleeder loose to relieve pressure. If the wheel releases then you know that its a hydralic problem. It sounds like you have something mechanical going on.. Gonna need to pull the wheel and try to get the drum off.

 

Yeah, i cracked the bleeder screw and it banged and released...any suggestions that could be the problem to look for when i pull the drum off.

 

If it released when you open the bleeder, your problem isnt behind the brake drum but somewhere in the hydralics. Check the steel line that goes from the wheel cyl to the T where the flex hose is, make sure its not smashed shut. If the problem is further upstream, like the rabs valve or the flex hose, opening the bleeder on the other rear wheel should release the pressure just like it did with the locked wheel.