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I pulled the rear brake pads out today as a little winter project trying to chase a rolling noise from this past summer. I have a totally stainless steel system from the MC out to all corners. Using silicone brake fluid. Fluid level is up and never really add any. Can anybody venture a guess why this inboard pad from a rear caliper would look like this?
No I don't have a dial indicator. Good thought on weep between caliper halves. This system has been in place for several years and trouble free. Am I dreaming to just tighten the caliper halves?
given the stains I think perhaps Bluestripe might be on to something. You did say that you had no signs of fluid loss and given the noise issue I'd think if anything it might have lessened that ??
I'm also thinking that if runout were an issue, given the visible damage you would have felt it in your pedal..... no ?
A couple of reputable brake companies would tell you this is a silicone brake fluid problem.
I had a similar problem. You're going to have to replace the caliper. Then flush the system with denatured alcohol. I would next use DOT 3 if this is a street car.
Now everyone will tell me how they've used silicone fluid for the past three decades and never had a problem. OK.
I pulled the rear brake pads out today as a little winter project trying to chase a rolling noise from this past summer. I have a totally stainless steel system from the MC out to all corners. Using silicone brake fluid. Fluid level is up and never really add any. Can anybody venture a guess why this inboard pad from a rear caliper would look like this?
Dennis
It looks to me like the pad has been ground off by abraiding on something as the wheel turns. Look at where the caliper came off and see if you see witness marks. That doesn't have anything to do with a caliper leaking but it could be the source of your noise.
I'd think if the caliper was leaking, that pad would be wet across the whole face of it. I'd resist the urge to flush out the Dot 5 at least until you find out what's going on.
The Feds have a FMVSS standard on all brake fluids sold to the public that states they MUST be compatible with existing soft brake components and that includes seals, cups and hoses and applies to Dot 3,4,5.1 and Dot 5. So until someone shows PROOF that Dot 5 will damage current brake system compnents, I'll continue to dismiss any claim that owners should discontinue use of same.
It is odd where the brake pad is showing to be wet and the fact that it is breaking down exactly where it is showing wet. Your brake pad backing plate appears dry and that would be closest to the caliper and pistons. Normally leaks travel with gravity or rotation and your wet spots defy both of those normal leak paths.
Your leak appears to be creeping in from both ends.
What did the pad look like on the other side of this caliper?
I can't say I have ever seen a pad showing the issue yours has.
If your brake fluid is not low and the caliper shows zero signs of leak I think I would check run out on the disc and put new pads in.
The pad shows the markings of running on a smooth rotor, no odd wear marks other than the two ends. Are you cleaning your rims and spraying something that is getting on your pad and breaking it down?
The pad in the pic is the inboard pad. The outboard pad was dry and smooth with sharp edges. I use no chemical cleaners on my wheels just car wash and water.
You have a good eye and what you are saying is connecting a few dots. It does appear like something has been striking those outside lower corners. This pad came from the inboard side so it is hard for me to see the back of the rotor because the backing plate is in the way. Over the summer I had a rolling noise both forward and backward coming from that corner. Sounded like a wheel bearing or a U joint. Two guys that rode with me to listen thought it sounded like the pinion gear. Well the more I drove it to people to listen to the noise it got to be less and less and now has disappeared. Along with the stainless brake system the parking brake was replaced in the job as well with stainless parts. I do use the parking brake at times. I wonder if a part from the parking brake assembly is loose in the there and somehow rotating with the disc. Now that the corners have been chewed off it clears and my rolling noise is gone. My parking brake seems to still be working although I do have to pull it out pretty far now.
Yes the Bills. Well I was a high school wrestling and football coach for 31 years. I don't like to blame coaches or players for that matter. I know there are a lot of things that go into good teams. What appears to the eye is only a part of it.
Now the wheels. Those are American STICS IV. Long out of production. Silver spokes are a dead match for the car. What appears to be a trim ring is actually a machined surface right into the wheel. Thanks.
I just rebuilt a leaking rear caliper on my 66 and the inside pad had similar stains on the lower corners. The stains were lighter on mine and I didn't have the deterioration yours exhibit but the location and general appearance of the stains matched yours for the most part.
I just rebuilt a leaking rear caliper on my 66 and the inside pad had similar stains on the lower corners. The stains were lighter on mine and I didn't have the deterioration yours exhibit but the location and general appearance of the stains matched yours for the most part.
So you would say that if this pad was contaminated with Dot 5 brake fluid it might just attack the pad and cause it to crumble away?
I have DOT 5 in my car but I think the caliper had only been leaking a month or two. They deterioration might depend on the pad composition too. I'm guessing those are organic pads - but not sure? I can't think of anything in there that could start rubbing or grinding on the pad on the corners.
I can't think of anything in there that could start rubbing or grinding on the pad on the corners.
I can't either and I've never seen a brake pad just crumble due to contact with brake fluid. Any kind of brake fluid. Never seen a pad where the material just crumbled period.
That's why I suggested the OP get down under the fender and have a look at where the back side pad called home and see what else it might be sharing a bed with.
Agree that it might be a brake fluid, had just a similar issue last year. Currently looking for a good brake parts provider, any reviews on this Canadian company ?
It just seems that if it were from contact, that you would see the damage in a circular arc across the entire bottom of the pad. It the pad were hitting the shield and then riding up over it, he would have to be going forward and backwards alternately to get both ends - and I would think there would be a heck of a noise accompanying it. Also the ends of the shield should probably show some wear.
You might want to get some litmus strips and check the pH of your brake fluid.
12-10-2016, 01:00 PM
Help with a '66 rear brake pad
Dennis
