Brakes grinding sound/feeling when warmed up, nothing when cold

[crudster]

Well folks, after my long post about changing front brakes and the in's and out's of changing your front brakes - I continue to be plagued with a (seemingly) unsolvable problem.

The issue:

When driving for a period of time and braking normally (approx 6-10 stoplights in daily driver type driving), the brakes will exhibit a grinding feeling accompanied by a grinding noise. After this starts it will continue at each stop light. The sound/feeling only happens near the last 20 feet of my stop, so at speeds <10mph.

Background:

This started soon after i replaced the front pads/rotor on my explorer (03 XLT 4x4). Initially i thought it was wearing in of the pads / rotors. Four weeks later, im not so sure. I've checked everything out and there is no visible damage to the pads / rotors.

I did have a siezed caliper after the brake job and did replace the calipers (front - both sides) with reman bosch brand calipers, they perform well.

So we have, new rotor, pads & Caliper.

Then i thought, well maybe its the back brakes. So i just replaced those (the kit came with pads / rotors for all 4 wheels). After replacing those today, the problem persists!!!!

Oddly, the only temporary fix i've found is when i remove the front pads and rubbed them on sandpaper giving them a new "face". This removed the problem for a week and then it came back (i thought it was a fixed problem hence the info in my previous post). However, during that week i didn't drive a whole lot and most trips were short.

Did i mention that if the brakes cool the problem goes away completely???? So if i'm driving in town and its getting really grindy feeling & loud and then hit the highway for a few minutes and then stop its fine again!!!

What am i missing? Did i ruin my pads when the caliper stuck? Only turned the one rotor blue, didn't even make smoke / smell bad. when i resurfaced the pads there were no white swirls or glassy finish on them. the rotors appear fine (inside and out) and are starting to darken with pad material as they should....


HELP!!!

 

[crudster]

Just had a thought...

I have cross drilled rotors, could they be installed backwards?

The drilled holes are in a wave and the hole closest to the outside of the rotor contacts the pads LAST in forward operation. Is this the right or wrong way?

 

[crudster]

Contacted the manufacturer (Ace Rotors), they says the rotors can be installed in either direction. Problem still persists.

Perhaps is the caliper slides, even though the calipers are new and i thought i greased them. Maybe im missing something. Will liberally grease them one of these nights and see if that makes a diff.

 

[crudster]

Well folks, its time to wallow in defeat. It cant be solved and doesnt seem to have any adverse problems other than a weird feeling and sound. Braking is not compromized and no components are failing / grinding down.

Today i took it all apart again, removed the CRC goop from the backs of the pads, liberally applied caliper grease to the backside of the pads and "ears". Applied the shims that came with the pads, then greased the fingers and pistons of the caliper. What the heck else could i possibly grease!

This is all based on recommendations from brake install guides over the internet.

see: http://pages.sbcglobal.net/gorf/bmwtips/brakesqueal.html

Pads could be bad, rotor could have a micro crack. someone might not like me, either way unless someone has a definitive answer, im going to drive on these till they wear out. I've put about 2500Km's on these pads and it doesnt seem to be harming things...

 

[bisjoe]

Do the brakes stop you well, without pulling on either side? If so it may just be poor quality pads.

That's typical of certain brake pads, and always goes away when you rough them up a bit. Check the box they came in, were they made in China? When you buy pads at the auto parts they will have 3-4 kinds from $29 - $100/set, I always go for at least the middle ones. You might also share the brand of the pads for others, if it does turn out to be the problem.

 

[crudster]

Sadly, i bought these off ebay so i don't know the brand / performance. The seller is Ace Performance Rotors but the originator is unknown. The seller said if i take them into a brake shop and get a note saying the pads are bad, theyll replace them at my shipping cost. For the cost of the inspection and mailing them out (while my truck sits in my garage undrivable!), i could just buy another set of pads. Buyer feedback was great for this product so i think it just might be bad luck. I need to trek to San Francisco this summer, may just pick up a set of pads then and replace at that time - Americans don't get ripped off *as bad* as us Canadians for parts.

No pulling / adverse braking performance. Braking power is as good / better than the previous set. I too am leading towards bad pads. I've heard that the pads can become contaminated (with oil or other particulate) and when hot will "Chatter" on the rotor as the oils make their way to the surface. They could also just be cheap.

Thanks for the response.

 

[Amythestm]

You know, I have a 2005 Ford Explorer and Im having the same problem as well. We also replace all four barkes and rotors, and this problem still persists. It only happens when our brakes are warm as you've mentioned, and we for a moment thought it was bad callipers. Now after reading all your posts, Im not so sure. We did buy inexpensive brake pads for the front, and I'm wondering if that could be the problem.

 

[crudster]

Interestingly, i've now put on at least 4000 miles on these new(ish) brakes and pads and the problem hasnt gone away though the grinding feeling happens much less often. The high pitch squeal comes and goes though most problematic during stop and go driving. Im on vacation in California and drive the coastline beating my brakes up incessantly over the last 2 weeks. They perform great but the squealing hasn't subsided . I've decided to keep them and just put up with it.

 

[jrford]

about a 1-2 years ago the OEM warped pretty bad and stopped poorly.
Tried a couple of different combo's of pads and rotors. . .

The final set which has stopped great and no noise. . .might have gotten lucky??
Raybestos Adv Matl Rotors, and EBC6000 Greens came with shims, also used the orange stuff on the back. . .silence and they stop great. I hate to suggest $$$ but EBC stuff i've been impressed with, it even comes with a break-in compound on the pads.

Sounds like questionable materials somewhere. . .oh by the way cross drilled dosn't do much. . imho.

On a side note have you check the Parking brakes? the pad material with seperate from the backing plate. . . they usually rust up bad too. I'd assume the noise is the Front?

 

[13SantaFe]

I was having the exact same issue, just as you described. After much investigation and research I discovered that my master cylinder was overfilled. To the top right to the cap. I removed enough fluid to get it just below the max mark and the grinding issue when hot went away.