slappy41

Hello all, newbie here. I have a question about a brake issue i have got and i'm running out of options except just swapping parts out until i get it fixed which is real expensive. I bought a wreck 1991 4x4 x-cab, frame was bent but i didn;t think it was to bad. After i got it to frame shop, i was looking at around 12 hours of labor time to straighten it which ata 75.00 a hour rate, i decided to swap out frame wiht another one. Now i have it all back together and all parts came off my old frame and was swapped onto new frame. My issue is i was bleeding brakes, and I undid the LSPV under bed and starting bleeding RR,LR,RF,LF procedure and thought i had all air out. My issue my front brakes lock up on both sides. Now i can open bleeder valve and pressure will be reliefed but only till i hit the pedal again. I do know the brakes worked fine on the wreck frame because i drove it down the drive way with everything cut off it. Any help would be greatly appreciated. Thanks

wyoming9

iTrader: (1)

Just what do you mean lock up??

At What speed?/

Or do you mean your calipers don`t release ??

Till you open the bleeder valve??

How long did they sit Perhaps time for a rebuild.

Now the pads do stay pretty tight against the rotor. without a wheel you might not be able to spin them by hand.

slappy41

The brakes lock up to a point i have to put it in four low to get it to move. Calipers don;t release unitl i open bleeder valve. The truck was wreck one week before i bought it and i've had it down for 3 months doing the frame swap out. I drove the truck down the guys driveway (1/4 mile guessing, long driveway though) and back before i bought it and they seem to work fine. I made up four lines last night and stuck them on bleeder and open them with teh hoses in brake fuild and pump the pedal, refilling M/C as needed until i had pumped 5 resevoirs through the system and brakes felt fine. I dorve it around a city block and before i got half way around they started slowing it down. When i got aorund to garage and stopped it wouldn;t dong anything but spin back tires, had to put in 4 low to pull back into garage. Thanks for replying hope this fills in some of the blanks

RJR

Something is trapping the fluid in the lines and not allowing the pressure to release when you take your foot off the pedal. I would suspect a stuck valve in the master cylinder. I've heard that kinked or collapsed brake lines can also do that. Check your flexible lines.

lobukbuild

not knowing if you took anything apart or not, but could you possibly have the lines connected wrong? the lsv at the rear also has a line going up to the front brakes. just a couple of thoughts that came to mind.

slappy41

thanks all for your help, I'm going to check the LSV on the rear because i did indeed take that off old frame and install on new frame and i hope i have the two line coming and going from the front crossed. I did have all lines dissconnected at frame on the front but i marked them and reinstalled them correctly,(chekced myself on that last night) i used all lines from old frame to new one. Man i sure hope it's the lines on the LSV. Again thanks so much for your guys help, I will let you knwo what I find..

slappy41

well found issue, loukbuild was spot on. I had the lines swapped around on teh LSPV in the rear which caused it not release pressure. As soon as i lossen the lines,and got a face full off brake fuild ( which taste awful) i knew that was the point that was holding my pressure. I drove truck around a little bit and brakes seem fine now. Thanks for your guys help.