Bad Caliper or something elce?

[Cstoliker]

Been having some trouble with a break sticking when hot. Seams to be the left rear. I've replaced the pads, brake hose (on that wheel), greased guide pins and of course, bleed the system.
After the rig has sat for a while the brakes with work well but after getting hot it some times sticks. I've driven recently an 80 mile trip (mostly highway) and had no problem. But then a quick 5 mile trek to get a safety inspection it started sticking on the ride home.

Normally when the sticking occurs I'll noting a pulsing when breaking that's not normally there and at low speeds squeaking.

Before a replace the caliper, is there anything else that could be the cause? Both roters routinely get to 450 degrease after driving so its possible both are sticking to some extent but the left you can smell burnt brakes when it happens.
Is this typically of a bad caliper? Failing only when hot and sometimes working normally?

I guess the best diagnostic procedure would be to drive it it happens then crack one of the bleeders open and see if the system is under under pressure.


The first time it happened was on a trip home from camp. It got so bad I pulled over and dumped bottled. Water on both rear calipers (I know not a great idea) but after doing that they seamed to work fine the rest of the trip home.

[Cstoliker]

This is a 1998 so it would fall withing the later model category.

[westend]

Cstoliker wrote:

westend wrote:
Yes, you need the pad ears to slide in their holders and, yes, good brake fluid in the system. What some may not realize is that this era of larger Ford chassis had significant problems with calipers sticking, It happens especially when rotors and/or pads are worn to the end of their lifecycle. There is something about the geometry of the caliper cylinder and the mating seal surface that causes them to stick in the extended position. I've repaired/serviced more than a dozen Ford trucks with the same problem. The ultimate fix was to replace the caliper and they should be done, at the least, in pairs.

So the old warn pads may have been the cause. I'll still do my line pressure test to confirm but that makes sense. Did the bad calipers you've seen from this stick randomly while other times work normally?

Instead of looking at the problem from one part being at fault, it's better to look at the failure of the brake system (in this case, sticking in a position) as a progressive failure and interrelated parts problem.
As the pads and rotor wear, the caliper extends and retracts at greater length of travel. The caliper cylinder is pushed further out so that the pads are in contact with the rotor. This puts the cylinder and its seal at a position closer to the outside of the caliper, a place where road debris and brake dust may have settled previously.
My theory is that the outer caliper seal and mating surface see more wear and that the close tolerance of the cylinder in the caliper cause the binding of the seal and/or cylinder. On my own Ford trucks, I pay attention to the caliper mud seals and I will clean that area and apply some oil or spray underneath the outer mud seal. Whether this buys me time or is especially effective is unknown. I've had mixed results. Later model Ford trucks have a different caliper and don't seem prone to the same failures as those from 1995-2002.
Hope this helps.

[Cstoliker]

westend wrote:
Yes, you need the pad ears to slide in their holders and, yes, good brake fluid in the system. What some may not realize is that this era of larger Ford chassis had significant problems with calipers sticking, It happens especially when rotors and/or pads are worn to the end of their lifecycle. There is something about the geometry of the caliper cylinder and the mating seal surface that causes them to stick in the extended position. I've repaired/serviced more than a dozen Ford trucks with the same problem. The ultimate fix was to replace the caliper and they should be done, at the least, in pairs.

So the old warn pads may have been the cause. I'll still do my line pressure test to confirm but that makes sense. Did the bad calipers you've seen from this stick randomly while other times work normally?

[Cstoliker]

Gdetrailer wrote:

John&Joey wrote:

Cstoliker wrote:
As stated above its already been done. I cleaned and greased all the moving parts. Caliper does not have bolts. Just slide pins.

I've fought the same problem with my '96 Class A F53. Did all the standard stuff like you did. Replaced calipers with the best, and changed brake fluid every two years. Only way I could ever win. Even then, there were times I thought they were dragging after sitting for awhile.

Good luck, BTW backing up and hitting the brakes seem to help break them free.

Folks, in spite of what you think, it is not the calipers OR the pins.

The problem is the PADS FIT TOO TIGHT in the calipers.

What I have run into is the pads when new don't slide easily, once they sit they get the chance to RUST. Once rusted the pads no longer move back as they should after you let up on the brake pedal.

The fix, well believe it or not FILE the ears of the brake pads that fit in the caliper slots. If rusted you NEED to ensure ALL the rust is filed off.

In a nutshell, the brake pads MUST slide EASILY in the caliper holder, if they don't then FILE some of the material on the ears of the pads until the pads slide easily BY HAND.

I have had this happen to several trucks and had to use a hammer and chisel to get the pads OUT of the caliper.

I have thought about putting some anti seize on the ears but I am concerned about that getting on rotors, pads or collecting dust/dirt.

So far my "fix" has been working for several years on one of my trucks 🙂

Should have mentioned it earlier. The problem started before I changed the pads. I took them apart to clean and grease, saw they were warn and decided to change them while I had it apart.

[John_Joey]

Cstoliker wrote:
Funny you should mention that. For me I was thinking backing up and hitting them are what caused it. The ride to somewhere was fine. It's after I get to the destination and backing up to park it was triggered it. And would drag on the way home.

For me the worst was about 50 miles after I left the Gulf coast. At that point I would have to start putting my foot into the gas and could smell heat. My clue a caliper was sticking. I'd find a good place backed up 5 feet, and hit the brakes hard. Repeat 6-12 times and then I was off an running again.

[westend]

Yes, you need the pad ears to slide in their holders and, yes, good brake fluid in the system. What some may not realize is that this era of larger Ford chassis had significant problems with calipers sticking, It happens especially when rotors and/or pads are worn to the end of their lifecycle. There is something about the geometry of the caliper cylinder and the mating seal surface that causes them to stick in the extended position. I've repaired/serviced more than a dozen Ford trucks with the same problem. The ultimate fix was to replace the caliper and they should be done, at the least, in pairs.

[Gdetrailer]

MEXICOWANDERER wrote:
I changed to silicone brake fluid years ago and all this kind of nonsense went the way of the dinosaur.

:R

Silicone brake fluid has NOTHING to do with anything OUTSIDE the wheel cylinders nor does it "fix" anything other than perhaps a little brake FADE under heavy braking.

There is no "miracle cure" here, if the pads are not sliding EASILY in the holder then they WILL STICK.

[MEXICOWANDERER]

I changed to silicone brake fluid years ago and all this kind of nonsense went the way of the dinosaur.

[Gdetrailer]

John&Joey wrote:

Cstoliker wrote:
As stated above its already been done. I cleaned and greased all the moving parts. Caliper does not have bolts. Just slide pins.

I've fought the same problem with my '96 Class A F53. Did all the standard stuff like you did. Replaced calipers with the best, and changed brake fluid every two years. Only way I could ever win. Even then, there were times I thought they were dragging after sitting for awhile.

Good luck, BTW backing up and hitting the brakes seem to help break them free.

Folks, in spite of what you think, it is not the calipers OR the pins.

The problem is the PADS FIT TOO TIGHT in the calipers.

What I have run into is the pads when new don't slide easily, once they sit they get the chance to RUST. Once rusted the pads no longer move back as they should after you let up on the brake pedal.

The fix, well believe it or not FILE the ears of the brake pads that fit in the caliper slots. If rusted you NEED to ensure ALL the rust is filed off.

In a nutshell, the brake pads MUST slide EASILY in the caliper holder, if they don't then FILE some of the material on the ears of the pads until the pads slide easily BY HAND.

I have had this happen to several trucks and had to use a hammer and chisel to get the pads OUT of the caliper.

I have thought about putting some anti seize on the ears but I am concerned about that getting on rotors, pads or collecting dust/dirt.

So far my "fix" has been working for several years on one of my trucks 🙂

[Cstoliker]

Funny you should mention that. For me I was thinking backing up and hitting them are what caused it. The ride to somewhere was fine. It's after I get to the destination and backing up to park it was triggered it. And would drag on the way home.
I'm just gonna have to get them to do it then quickly jack a wheel off the ground, (confirm its stuck) then crack the bleeder valve. If fluid spews out under pressure it will at least tell me it's a master cylinder or line problem.
If no fluid comes out under pressed then it hast to be the caliper.

[John_Joey]

Cstoliker wrote:
As stated above its already been done. I cleaned and greased all the moving parts. Caliper does not have bolts. Just slide pins.

I've fought the same problem with my '96 Class A F53. Did all the standard stuff like you did. Replaced calipers with the best, and changed brake fluid every two years. Only way I could ever win. Even then, there were times I thought they were dragging after sitting for awhile.

Good luck, BTW backing up and hitting the brakes seem to help break them free.

[Cstoliker]

As stated above its already been done. I cleaned and greased all the moving parts. Caliper does not have bolts. Just slide pins.

[B_O__Plenty]

It may be the caliper slides and not the internal parts of the caliper. Try cleaning up the bolts and area on the outside of the caliper where it mounts. There may also be some bushings where the attaching bolts slide through that are stuck or rusted. On the GMs I've had this has always been the problem, not the caliper itself..

B.O.

[westend]

'98 Ford, replace the calipers. I have tried to clean the sealing surfaces and lubricating but the Ford truck calipers are notorious for this type of failure.