sound like a stuck caliper?

[jgilbs]

just replaced both rotors on my 92. now BOTH calipers are sticking! they are only a month old! is there anything else that can be causing this? my brakes are dragging on my brand new rotors and i really dont want to replace the calipers since i dont think its them. did i miss something when i reinstalled my rotors/bearings? (its the brake pads dragging and not the bearings)

 

[Runnin'OnEmpty]

Jeff, all brake pads drag to a certain extent. When you turn the wheel by hand, you can hear them drag, but the wheel should still be easy to turn. It's doubtful that both calipers would be sticking at the same time. A sticking caliper is very apparent; the wheel will be very hard to turn. Also, a sticking caliper will make the vehicle pull to one side, and it will get very hot.

The only other things that could cause this are the master cylinder or the proportioning valve. I doubt if these are the causes, unless you've had the master cylinder off.

 

[jgilbs]

they both are dragging. it is very difficult to turn the rotor and it gets very hot when i just drove like a block. i disconnected the caliper from the wheel and then used the brake pedal to bring the caliper to its full travel (i was gonna clean out any dirt while the piston was extended) now the piston will not retract at all with the c-clamp. is this normal, once they pass a certain point, to not return? im gonna be getting new hoses and calipers today(lets hope that solves the problem)

 

[410Fortune]

Yikes you pressed the brake pedal with the calipers not installed? NO NO NO you need new calipers now....

 

[jgilbs]

well i was pretty sure i needed new ones anyways, so i just wanted to see how bad they were. with my luck, now its gonna turn out that i need a new master cylinder. hopefully not.(knock on wood)

 

[410Fortune]

I doubt you bottomed out the master, but it is possible.
You pushed the caliper plungers past the point where they are sealed, then when you press them back in it will never be right again.

I bet you wont ever do that again
use a soft brush if you want to get the dirt dust out of the rubber dust cap on the caliper...

 

[jgilbs]

installed a new caliper - and its STILL sticking!!! does this mean i need a new master cylinder?

 

[410Fortune]

You are telling me you just installed a new caliper in that amount of time and bled the system? Did you replace both sides?

Yes it is possible you bottomed out the master cyl. Did the pedal go to the floor at one time?

 

[jgilbs]

pedal was able to goto the floor - but there was still pressure. i only replaced the caliper that i had previously destroyed. yes, i did it that quick - my wheels were already off . i bled the system - but before i did, it was VERY low on fluid as a result of disonnecting the hose to the caliper and leaving it off all night(pedal feels firm now, tho. doesnt seem like the master cylinder got any air into it.)

 

[410Fortune]

Remove the line for thte front brakes and bench bleed the master cyl while it is still on the truck, then reinstall the line and bleed the system again.
Getting air into the master will not kill it, pushing the plunger/pedal to the floor can.

Once the system is bled and everything is installed, start the truck (for vacuum to the booster) and press the pedal firm a few times, see if they still drag.
Also are you sure it is the brake that is dragging? what about wheel bearings?

 

[jgilbs]

would bad hoses leading to the caliper cause this? mine look pretty bad - and are cracked real bad. they arent leaking fluid, and i got new ones, but will this help any?

 

[jgilbs]

I know its not the bearings because I greased them up real well. i know its the calipers because when they are off, the rotor spins great. plus, i cant even fit a very thin sheet of paper between the pad and the rotor.

 

[410Fortune]

Rubber lines swell when they get old, causing a soft pedal, but not damage to the caliper or dragging on the pads.

You have the anti rattle clip installed properly on the bottom of the rear pad?
did you clean the mounting surfaces on the caliper and knuckle for the slide pins?
Did you clean the slide pins and lube them?

If the slide pins are old (cracked rubber middle, old and flimsy) they should be replaced.

Also the hub is not locked it is? Causing you to turn the whole front axle and make it feel like dragging?

 

[jgilbs]

when i am turning the axle, the hubs are off. so, no, it is not a locked axle. i have new slide pins and sly-glide from napa. the anti-ralle clip is NOT installed as I dont know where it goes. would this cause the calipers to drag?

 

[410Fortune]

You cannot just leave it out and expect the brakes to work right.
The clip goes on the bottom of the rear padm it mounts as a psring to keep the pad from moving up and down and keep it snug against the knuckle.

The slots on the knuckle should be cleaned and lubed as well, where the rear pad mounts.

It might cause the pad to not sit properly against the rotor, and could cause a drag? I dont know but something is not right thats for sure.
If you cant find the solution at the rotor/caliper assembly then move on to the master.
a bad master usually causes weak brakes, not a dragging. Dragging is caused by either to thick of pads, bad calipers, pressure in the system, bad RABS valve.

 

[jgilbs]

im starting to think bad RABS valve. i did make the mistake of when I was trying to seat the calipers after I put them back on, I pushed the pedal as far as it would go a few times to get pressure. I got pressure, thats for sure where is the RABS located? how hard is it to remove? is it expensive?

 

[410Fortune]

Dont start jumping to conclusions! Throwing $$$ at it is not the way to go.

You likely bottomed out the master cylinder, but like I said I have not seen that cause a dragging, but I am sure it could...

to answer your questions, does your 92 have front ABS?

The ABS valve for an Explorer, if its 4wABS is located on the drivers frame rail, under the booster, you can see both brake lines go into it.
Yes it is very expensive for a new one.

 

[jgilbs]

I only have rear abs. What could it be besides a bad master cylinder?

 

[410Fortune]

Then what you have is a RABS valve, which is located near the back of the truck and does not need to be bled unless you have replaced the wheel cylinders in the rear brakes.

I suspect you bottomed out your master cylinder
But what happens if you go buy one, install it, bleed the RABS And all 4 corners, and it still drags?

testing the master cylinder is not something I know how to do, but I am suspecting you killed it

A new master is about $80 if I remember right, it must be bench bled, then installed, then like I said the RABS and all 4 coreners must be fully bled. Great time to replace those front lines

 

[jgilbs]

hmm since my calipers were $50 each, and i saw a napa master cylinder for $50, maybe i can return the caliper for the side i DIDNT destroy, and use that to buy a new master cylinder problem is, my rear wheel bleeder valves are so fargone last time i tried to bleed them, i ended up with 3 stitches in my knuckles.