Brake Help!!!!....my rears arent working...
Brake Help!!!!....my rears arent working...
ok so i got my explorer axle in and now i have rear discs....to my understanding the drums took more psi to work so if anything my rear end should lock up before my front....but my rears arent working at all......i jacked the back of the truck up and put it in 1st and let the tires spin...i gave it gas and pressed the brake petal as hard as i could....the tires slowed down but did not stop. now the pads that are on it havent been run in like a year or two so i was thinking they might need to break in but i have been driving the truck for about 50 miles or so by now and they still dont work....what could be the problem? thanks...also what did other people with the expo rear end do about the passenger side ebrake....if u have one u know what im talking about...
i already did pull the downey..sort of...when i bought the axle the guy gave my 2 driver side calipers...so i already went through all of that...i went to the JY and they let me swap mine for a set off a 2001 expo with 30,xxx miles...they were like band new...still gold colored....and ya i bled them and the petal feel nice and solid....here is the quotes out of my other thread...
ya i was thinking about using the ranger block and doing what u said...but this worked out fine and i have more slack in my line a full drop that i did with the ranger line...also i went to the JY today and he let me switch out the crappy calipers that came on the axle when i bought it on craigslist for some nice ones of an 01 expo with 30,000 miles...i love having hookups there...so far i got the u bolts and top plate of an f-150 for free, the calipers, brake lines, and the ebrake cable all for 5 bucks...so i got the new calipers on and hooked up and bleed. now when i hit the brake petal it stops me very fast and works good...but i still cant get it to lock up at all. also i went to a gravel road and only the fronts locked up...then i did a brake stand and i could press on the brakes as hard as i could and i didnt notice a difference in the rear tires spinning...so for some reason my rear brakes arent working. could that be the prop valve? my petal is nice a firm like it should be but something is not right...what do u think it could be?
on my moms jimmy when the abs kicks in it vibrates the petal and makes a wierd noise....my truck has never done that so i assumed that the abs didnt work...and i was flexing on a hill to test out the limited slip and once one tire got off the ground i tried pressing the brakes to even out the resistance and see it i could get it to go further up the hill and when i pushed the brakes the rear tire that was spinning didnt even show down...that means that something is not right.
Why are you using old pads? I know when stuff is new you have to bed them in by doing a special, and very fun, process. But you should be getting brake pressure to the claipers to stop the wheels when jacked up.
well my rears are getting better i think...they actually worked in the gravel the other day...now why wont they lock up on the asphalt....even in the rain...also i have to push my petal down really hard to get it to stop fast...(trying to make it skid) and it takes a lot of pressure to do that....i don think it is supposed to take that muck force...no other car ive ever driven is like that? what could be wrong? thanks
Member
Joined: Mar 2007
Posts: 2,598
Likes: 14
From: Upstate,NY
I'm going to guess that the proportioning valve that limits the fluid pressure to the rears is different between vehicles that use drum brakes and those that use disc.
Drum brakes need less pressure to operate than disc brakes.
Drum brakes need less pressure to operate than disc brakes.
ok so if they need more pressure how does adding a proportioning valve help that...wouldnt that only lower the pressure thats going to the rear brakes? do i need to get rid of the factory prop valve? i thought i read on here that discs take less pressure than drums so that had me all confused...lol
i didn't have to do anything special to any part of it. everything hooked up and worked as it should. have you pulled the calipers off and tried pumping the brakes to see if they are even moving? it's possible the calipers are seized.
Member
Joined: Jul 2005
Posts: 1,902
Likes: 2
From: Sask, Canada
That's correct, discs require less pressure to lock.
I suspect the pads may be contaiminated. I'd just put on new pads, as that will more than likely solve the issue. If the pads have come in contact with brake fluid, engine oils or certain transmission/hydraulic fluids, they're pretty much toast. They can be cleaned sometimes, but new pads aren't really all that expensive . . .
If it were a matching pair of calipers off the same vehicle I'd suggest to see if the brake pistons were locking or seizing up, but I doubt that's the case.
I'd bleed the brakes a couple more times to be sure. The junction block and calipers can hold air pockets causing a normal brake pedal feel, but reduced brake application pressure.
I suspect the pads may be contaiminated. I'd just put on new pads, as that will more than likely solve the issue. If the pads have come in contact with brake fluid, engine oils or certain transmission/hydraulic fluids, they're pretty much toast. They can be cleaned sometimes, but new pads aren't really all that expensive . . .
If it were a matching pair of calipers off the same vehicle I'd suggest to see if the brake pistons were locking or seizing up, but I doubt that's the case.
I'd bleed the brakes a couple more times to be sure. The junction block and calipers can hold air pockets causing a normal brake pedal feel, but reduced brake application pressure.
every one says something different..some say discs take less pressure...some say they take more...im so confused..lol but ya i think they have gotten better. ill bleed them a couple more times and if that doesnt do anything ill get new pads.
well maybe thats the reason my truck wont lock up...i got my front pads from the JY too and they could have been contaminated......any body recommend some good brake pads? or will the cheapies from kragen work just as good?
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