Auto/Car - Grinding noises when breaking

[schnee]

Friends car has a front passenger wheel that has a grinding noise when braking (disc brakes).. the grinding can also be felt lightly in the brake pedal.

It's not a "loud" grinding.. but if you were a pedestrian on a corner... you would probably notice it as the car came to a stop.

Any ideas what this is? Doesn't happen all of the time, but only happens when braking when driving at slow speeds.
Ex if you're driving 15k, put the brakes on lightly.. they will start to grind.

Car has been to the dealer a few times for this - they've replaced the pads, cleaned the brakes, turned the rotors, etc... but can't seem to fix the problem.

So the grinding is not from worn pads, or warped/worn rotors.
No rocks in the brakes/pads...

Any ideas?

[CaptainCrunch]

I don't know, cracked bearing.

Dead cat stuck in the wheel well.

[Dion]

I wonder if the ABS brake system is malfunctioning.

[BlackArcher101]

Make and model of car please.

[Shazam]

Go somewhere else besides the dealer.

Could be the calipers, but grinding sounds when braking is almost always worn rotors and pads.

[PIMking]

Its the brake pads and or rotor. the last time they were done they could of just put pads on and called it done and not touch the rotors there in for eat up the new pads. shoot I wish I lived in calgary I would change the pads and rotors for free as long as they bought the parts. It should only take 15-20 mins.

[CRXguy]

time to change the pads.

[Dion]

Maybe worn wheel bearings. They can make grinding sounds when they are going.

[Drunk Skunk]

What color is the car? It's very important to the diagnosis

[BOSSY]

Originally Posted by CRXguy

time to change the pads.

If it's grinding you'll be changing (or at the very least) turning the rotors too... Too long between brake jobs!

[Bobblehead]

My father (a mechanic) once told me if your breaks are squeeling, it is on purpose to let you know the pads are low. If it is grinding, you waited too long and the bill has a chance to get much bigger .

[McMack]

I went through a long ordeal with the dealer with a similar issue. After driving for an extended period of time, there would be a grinding noise when breaking from one wheel. Had it back to them at least 6 times. They did everything including turning the rotors. In the end, they finally discovered that one of the rotors had a very imperceptible crack that would only become a problem when the rotor became hot. For many cars, the price difference between turning the rotors and new rotors is small... these days, I usually insist on getting new rotors rather than having them turned.

[schnee]

Originally Posted by Drunk Skunk

What color is the car? It's very important to the diagnosis

Laugh... "Oh it's a big pretty white car with red stripes, and curtains in the windows... and wheels. Looks like a big Tylenol."

Originally Posted by Shazam

Go somewhere else besides the dealer.
Could be the calipers, but grinding sounds when braking is almost always worn rotors and pads.

Originally Posted by Dion

Maybe worn wheel bearings. They can make grinding sounds when they are going.

Apparently each time the car was taken in for this (been 4 or 5 times now), on both front wheels they turned the rotors, replaced the pads.... that day grinding was still coming from the same front wheel.

It's a newer car (04 or 05) that is coming off warranty and lease soon.. so
friend is worried they will get stuck paying for something that should have been covered by the dealer/warranty.

I'll tell them to have the car checked somewhere else.

[schnee]

Originally Posted by McMack

I went through a long ordeal with the dealer with a similar issue. After driving for an extended period of time, there would be a grinding noise when breaking from one wheel. Had it back to them at least 6 times. They did everything including turning the rotors. In the end, they finally discovered that one of the rotors had a very imperceptible crack that would only become a problem when the rotor became hot. For many cars, the price difference between turning the rotors and new rotors is small... these days, I usually insist on getting new rotors rather than having them turned.

Thanks! I'll pass that along too

I'm assuming the mechanics at the dealer road test before and/or after.. if it's a quick trip around the block.. they might not get them hot enough for the grinding to be noticed (?).

[Aeneas]

Does your "friend" have any other problems CP can help with?

[JohnnyO]

Caliper is probaby stuck and the pad wore down to metal on metal with the rotor. Complete brake job is probably required. Rotors are cheaper to replace now then machine.