so lets just say i'm kinda mad. this starts about 6months ago. was loosing fluid to my rear brakes. couldn't find a leak. not my wheel cylinders nor my brake lines, no where. so after talking to a friend at napa he said maybe the master was leaking into the booster, so i got a master. took the old one off and it wasn't wet at the booster, had it so i replaced it anyway. still lost fluid, so i replaced the rear lines to the p-valve and from the p-valve the rest of the way to all the way to the wheel cylinders. after that i didn't loose any fluid but the pedal seemed to slightly fade. well about a week ago i started hearing a squeaking from the ft dr side. brake pedal felt kinda spongie so i figured my pads where getting bad and it was hitting the squealers.pads where still had about 10 32nds on them put pads on it, put my foot on the pedal and pumped the pedal to push the pistons back out. got a pedal but now it was fading almost instantly to the floor, turn the truck off and have a rock hard pedal. so i figured the booster is bad. replace it, no change. decided to bleed the brakes, no change. thought maybe the master just took a crap and decided if i'm gonna bleed them again im going to put another master new calipers and wheel cylinders on just to eliminate them. do it, bleed it and now it doesn't go all the way to the floor but still fades, feels spongie and i really have to push hard to stop. it also feels like the rear it stopping more then the front, could just be me. brake hoses where replaced about 3 years ago. abs unit still has the lines plumed through it but is unplugged from the rearend. got good fluid pressure out of everything. i'm stumped any suggestions would be great......sorry its so long.

 

I could also use some info as my brakes are the same only I think I'm just using the front although when jacked up and push brakes the rear do work but have a hard time stopping when hauling car trailer

 

I had sort of the same problem, I noticed on my truck that there were no sighns showing that I had a leak, so I took both rear wheels off and noticed that there was some little leaking from the rear cylinders, it was not enough to notice without the wheels taken off, might help, also if you replaced the master, you have to bench bleed them and then you also must bleed from the front and the back.


good luck

 

just put new wheel cylinders on. did bench bleed and bled starting at rr and ending at LF.

 

Thanks guys I did bench bleed the master and Ill check the rear also try to bleed them again

 

so here's what i did today. got another master, a brand new one. not a rebuilt one like the other two. bled it put it on, no change. i jacked it up in the back held my foot on the brake and hit the throtle. i got it up to abot 2k before the tires started to spin so i 100% think the problem is in the front. could the metering valve be bad? i get alot of fluid out of the front, enough to hit my inner fenders. the manual reads check with a helper. have helper press brake pedal and observe the stem. if valve is working correctly the stem will slightly extend out and pull back in when the pedal is released. i looked and it is moving. could a piece of debris be blocking something in the metering valve(p-valve)?

i'm ready to give up and sell the truck.......... help

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