Horrible, tooth shattering, grinding noise when braking hot.

XxJenoxX · Post by **XxJenoxX** » 23 Mar 2010, 18:08

Well, I think I found the solution to this, but if you have the same problem, check it out! I never would have thought of this...

So my car started making this AWFUL noise when coming to the slowest end of a firm, but not REALLY hard gradual stop. The noise is the kind of grinding that makes you wince, because it sounds like it's doing damage somewhere. Mostly with the kind of stop you make when you're impatient (like me) in stop and go traffic....low speeds with firmer pressure on the brake. It really did sound like something rough that was grinding...metallic, or dirt on bearings. So I was preparing myself to have a bad wheel hub bearing in the FRONT right. Would have sworn on my life that it was the front. This weekend, I took my car to my dad's house to have a look at the brakes, in hopes that we would find the cause there and it wouldn't be the bearing. He brought up the fact that since my rotors were warped and it only happened after extensive driving when things were really hot, maybe the heat was making the rotor warp a bit more dramatic, and something was scraping against the dust cover. So we took a close look at that, and decided to replace the rear rotors.

Took the REAR right rotor off, and to my surprise, there were heat cracks along the inside of the rotor, and silver rub marks on one of my e-brake shoes!!! It seems that it was as simple as the holding pin on the back of the shoe not being hooked, and the shoe was jutting away from the dust cover and rubbing the inside of the rotor! Granted, it hasn't been as warm out and I've been taking a less heavily trafficked route to and from work, so the brakes aren't getting as hot as they were with the longer trip and warmer weather, but I haven't heard the grinding since then!

Just thought I'd share that for those of you who have this HORRIBLE noise, but are thoroughly stumped.

Post by **phils94850** » 23 Mar 2010, 20:43

thanks for the heads up on this xx

XxJenoxX · Post by **XxJenoxX** » 24 Mar 2010, 16:17

Well the bad news on my heads up is that it wasn't the culprit...the grinding is back, haha.

But still, it's something to watch for if you have any extra noises in the rear! (heh)

Has anybody else ever experienced this? Could it be related to my bent hub? Because I just did the rotors and pads, and they are STILL squealing...so the hub obviously has to be done.

Post by **charlyW** » 24 Mar 2010, 17:17

When you replaced the brakes did you use any anti squeel compound ? could be you didnt use enough. Heat cracks would say the pistons are jamming in the caliper bores might be worth getting a repair kit then ejecting the piston and with some light emery paper just clean the bores up but make sure you wash the caliper out before putting it back together

XxJenoxX · Post by **XxJenoxX** » 24 Mar 2010, 17:19

I put shims on it, on the previous brakes, I shimmed, and shoe gooed the living crap out of them, second set of rotors and second set of pads that are insanely loud. Haven't tried cleaning out the calipers and pistons yet, though.

Post by **vegasjetskier** » 24 Mar 2010, 18:15

Does your e-brake mechanism work properly?

rixkix · Post by **rixkix** » 24 Mar 2010, 19:22

I have been having the same thing on my 1998 V70 T5 wagon. I have replaced the rear rotors, twice (One set was a set I pulled from the junk yard, one set brand new.) I replaced the pads, twice. I adjusted the inner e brake pads, and thoroughly cleaned EVERYTHING. Guess what, the noise persists. And it is the same thing, once they get a bit heated. Thought I could figure this one out myself, but i guess i'll have to give in and take it to my Volvo mechanic. It is a bit,(slightly) comforting to know that iI am not the only one experiencing this problem. Please post if anyone has come up with a solution for this.
Thanks

XxJenoxX · Post by **XxJenoxX** » 24 Mar 2010, 19:30

As far as I can tell, the e-brake seems to be working properly. I've never pulled it while moving, but it feels fine when I pull it.

Of course, it's hard to tell...especially since I haven't had anyone outside the car listen, since it only happens after 15 miles + of stop & go driving, but I could SWEAR it's in the front end. I do think that contaminated or bad bearings seem like a logical culprit, given the rough grinding sound to it.

EddieH · Post by **EddieH** » 24 Mar 2010, 20:18

I have the same issue with my 1995 850. Although, I wouldn't consider what I'm experiencing tooth shattering, it is very annoying. First started noticing it late last summer. Took of wheels one at a time, inspected brakes and calipers, lubed everything good. With the onset of cooler temps in the fall of last year, the problem went away. Went the whole winter without hearing anything. Now that it is starting to warm up again, I'm hearing the rumbling noise once again. It only occurs when braking and at speeds less than 15 mph and after the car is at operating temps. Doesn't occur when the car is cold. Not sure what to look at next. Wheel bearings, CV joints? Don't know whether to replace the rotors and all brake pads, this was done about 3 years ago and they looked good the last time I took everything apart. Any suggestions or helpful hints are welcome.

Eddie

XxJenoxX · Post by **XxJenoxX** » 24 Mar 2010, 21:00

It's not all that loud on mine, it just sounds very very very BAD. Like it's doing some damage. The only other noise I can think of that might match what you're saying is the vibration that I've experienced in hot temperatures. That was pretty obnoxious, too. But it didn't sound like it was really hurting anything.

Unless it's on my left, I wouldn't say CV....I just had my whole damn right front axle replaced, and to no avail. The bearings are probably going to be my next stop...that, or the hub that I think may be bent.