PBR caliper Questions

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Kidd-7

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I installed the PBR calipers about 4 years ago. I had some grinding noise and pulled the wheels, the passenger side inside pad was gone, all 3 other pads had ~1\4” of pad left.

Any input why that pad wore out so much faster?
 
These were brand new calipers, so hopefully not a sticky piston.
 
Normally I'd agree, but it wouldn't shock me if a new one was bad these days.
 
True, any suggestions on How I can test this? I did clean and lube the pins well this time.
 
-When you take off from a stop, you may hear a pop or click as the brake releases.
-Take it on a drive. If it is sticking bad enough it may pull to that side.
-The hub with the sticking caliper will get hotter than the other side. Need a IR thermometer to check.

I fought with one for several years. Piston housing was warped after it got hot several times. Replacement was the only cure.
Hopefully lubing the pins better will fix it. If it does the same thing on this set of pads, I would get a new one.
 
girdnerg said:
-When you take off from a stop, you may hear a pop or click as the brake releases.
-Take it on a drive. If it is sticking bad enough it may pull to that side.
-The hub with the sticking caliper will get hotter than the other side. Need a IR thermometer to check.

I fought with one for several years. Piston housing was warped after it got hot several times. Replacement was the only cure.
Hopefully lubing the pins better will fix it. If it does the same thing on this set of pads, I would get a new one.
Click to expand...
^ what he said. You can also switch the inboard pads from RF to LF so you don't burn through a new set.
 
No noticeable pop or pull. I’ll keep an eye on it. I don’t have an IR thermometer, may be able to borrow one. We also have a FLIR camera at work, maybe able to compare temps that’s way.
As a side note I’ve not replaced the front hubs on this one yet.
 
Kidd-7 said:
I installed the PBR calipers about 4 years ago. I had some grinding noise and pulled the wheels, the passenger side inside pad was gone, all 3 other pads had ~1\4” of pad left.

Any input why that pad wore out so much faster?
Click to expand...
You didn't follow the instructions, lol.
You have to grind a groove in the spindle to keep the caliper from hitting it as the pad wears. Otherwise, it hits, cocks the caliper to the side, and wears that side of the pad quickly. I wore one that far in a couple of years myself,lol. Look at it, you'll see it. It really is in the thread I followed.
 
I did grind, maybe not enough though. I will double check that.
 
if you look at the spindle that connects to the upper control arm you will likely see where the caliper is contacting it. As the piston pushes on the inside of the rotor the caliper slides inward and the pins keep it perpendicular to the rotor. As the pads wear the caliper must travel farther inward and makes contact unless you use a dremel and a rasp bit to shave off a small amount. Try not to leave sharp edges that could cause stress riser and possible failure. we're talking about thousandths of an inch in the right place.
 
It's more than that. if you bolt it on, with one pad out, it's about the thickness of fully worn pads; if it hits now, keep grinding. Like dude said, no sharp edges, to form a stress riser.Nice,rounded corners.
 
1722552061253.jpeg
Unless y’all see something I’m not, there’s enough ground out. Looks like I need a new caliper.
The FLIR showed the drivers side rotor at 130c, the passenger side 160c.
Also, by feel there is more rotational resistance on the passenger side.
 
My calipers are under warranty so I’ll process that with rock auto.
I’m going to flush the brake fluid also, how much fluid do our cars hold?
 
I have what is basically a hamster cage bottle that sits in the reservoir upside-down and feeds new fluid to the reservoir as I bleed the brakes. I fill the bottle with new fluid and flush until I get clear fluid coming out at the wheels.
 
KevinVarnes said:
It could also be a collapsed flexible brake hose, but with those things, my money is on the caliper. I usually just replace the hose while I am doing a caliper since it is cheap enough and I'm already into the hydraulics.
Click to expand...
Good point, my wife had that happen years ago and it caught fire.

When I installed these calipers I also installed braided SS lines, really hope that isn’t the point of failure.
 
Probably not, and since you have the fancy brake hoses on there you are probably good. If the caliper is noticeably difficult to retract by hand you can try opening the bleed screw. If it suddenly becomes much easier to retract then your problem is with the hose. If the effort to retract stays the same then the caliper is at fault.
 
I'm curious which rebuilt type it was. I'll want another set eventually.
 
KevinVarnes said:
Probably not, and since you have the fancy brake hoses on there you are probably good. If the caliper is noticeably difficult to retract by hand you can try opening the bleed screw. If it suddenly becomes much easier to retract then your problem is with the hose. If the effort to retract stays the same then the caliper is at fault.
Click to expand...
^ also this.
 
I read years ago, there were two piston types,stainless, and phenolic, and that one type was prone to sticking, but IDR which, but I doubt it was the phenolic; I use that for rocket engine nozzles.
 
I installed the new caliper. Looking at the temp of the rotors after driving to work the passenger side is ~20C hotter than the drivers side.

Does that difference seem reasonable or would we expect the temp differential to be closer?
 
I would think the temps should be within a few percent of each other if both sides were fully releasing after braking, and both sides were evenly conditioned for symmetrical braking friction. Are the rear brakes showing any odd signs?

Something else I've considered when chasing this kind of thing is rotors being perfectly perpendicular to the axis of rotation. Up here I have to fight the possibility of rust developing between the hub surface and the rotor, which makes warped rotors and sticky brakes all the easier to encounter.
 
Yes.The temps should be the same. Is that the same side as before?
if so, you may have a fucked up residual pressure valve. They're behind the drivers wheelwell liner, on the firewall; there's a left and right one.

Seems like these guys sell rebuild parts.

1996 - 1997 Ford F6SC-2B091-CA Proportioning Valve Rebuild Kit | Muscle Car Research LLC

www.musclecarresearch.com www.musclecarresearch.com
Teres a spring, a couple of pieces,and some orings. my pieces and spring had corroded, and stuck. I had a rear caliper that wouldn't retract.
 
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From the ride home last night; The temps on the rear brakes are really close to each other. The fronts were ~10c or less difference.
The feel of the braking is normal, no pulling. There is a rattle that is more pronounced on the passenger side, but I've read that's pretty normal with these calipers.

Grog, the passenger side is still the culprit there.
 
KevinVarnes said:
It could also be a collapsed flexible brake hose, but with those things, my money is on the caliper. I usually just replace the hose while I am doing a caliper since it is cheap enough and I'm already into the hydraulics.
Click to expand...

This is good advice. IMO even if the hoses seem to be working fine, it's a good idea to replace them if they are the originals. A benefit is the brake pedal feel usually firms up some after replacing old hoses.

I put PBR calipers on my previous MN12. For some reason they always seemed to have a slight drag. Not enough to heat up the rotors, but with the wheels in the air they always had a bit of resistance. I heard at some point that it's not uncommon for those calipers. The OE calipers never did that, and the Mark8/Sport calipers on my Cougar don't either.
 
The caliper I had trouble with was the pass rear. It was ok after replacing it. :)
 
Grog6 said:
Yes.The temps should be the same. Is that the same side as before?
if so, you may have a fucked up residual pressure valve. They're behind the drivers wheelwell liner, on the firewall; there's a left and right one.

Seems like these guys sell rebuild parts.

1996 - 1997 Ford F6SC-2B091-CA Proportioning Valve Rebuild Kit | Muscle Car Research LLC

www.musclecarresearch.com www.musclecarresearch.com
Teres a spring, a couple of pieces,and some orings. my pieces and spring had corroded, and stuck. I had a rear caliper that wouldn't retract.
Click to expand...

Dumb question, but does this kit work for '95s, too? Or is there a separate kit? Or are '95 brakes different and don't use that type of residual pressure valve?
 
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