Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

dirty brake pads?


robert smith's Avatar
Member

Join Date: Jul 2001
Posts: 323
IN

08-20-02, 07:49 AM   #1  
dirty brake pads?

hi

can you answer a question for me? I believe my brakes are squealing a lot because the pads might be dirty. The reason for the dirty pads is that I put on new pads without noticing that the back side of the rotors were rusted (the front face of the rotors were fine). I changed the pads after noticing the rusted rotors but since the pads were only on the car for about a week before I changed the rotors, I reused the old pads.

Some of you have mentioned that the pads squeal when dirty. Could this explain why they are squealing. I have already ruled out anti squeal compound as well as anything being loose.

My question is: If they are a little dirty, why doesn't the dirt wear away after a little while of using the brakes. In other words, why doesn't the dirt grind away and stop squealing?

thanks

bob

 
Sponsored Links
Joe_F's Avatar
Visiting Guest

Posts: n/a

08-20-02, 08:59 AM   #2  
Joe_F
Can't answer the question with any intelligence until you comply with the forum's rules on the top of the page about required information when posting.

Could be bad rotors and bad pads from the bad rotors.

 
robert smith's Avatar
Member

Join Date: Jul 2001
Posts: 323
IN

08-20-02, 04:51 PM   #3  
sorry

1994 cutlass supreme

i asked this question to you a month ago and i was told it is probably dirty pads and/or cheap pads. my question still is, if it is dirty pads, why don't they stop squealing after the dirt has been ground off?

thanks

 
bejay's Avatar
Member

Join Date: Dec 2001
Posts: 2,538

08-21-02, 05:56 PM   #4  
i would say in your case it was the brand of pads, often you can take pads off and clean them with rough sandpaper and eliminate the squeeling only temporarily, and it will soon return.
dirt ,metal ,rust , can get imbedded into the pad and will not just fall out as the pad wears.

 
robert smith's Avatar
Member

Join Date: Jul 2001
Posts: 323
IN

08-21-02, 07:59 PM   #5  
okay, i guess i'll have to take them off and replace them again.

i go to autozone and buy their middle of the road pads but they are still cheap ($17). Do i have to buy their most expensive pads that cost around $100?

Or do you have another suggestion?

thanks

bob

 
bejay's Avatar
Member

Join Date: Dec 2001
Posts: 2,538

08-21-02, 09:58 PM   #6  
i believe wagner makes a brand called thermo quite or something like that.

 
Joe_F's Avatar
Visiting Guest

Posts: n/a

08-22-02, 05:43 AM   #7  
Joe_F
Any quality Wagner, Raybestos or Delco pad will work fine on this application. Same for the rotors. Only use good quality Canada or US made replacements. Skip the offshore junk and keep it on the shelf.

 
josh1's Avatar
Visiting Guest

Posts: n/a

08-22-02, 08:16 AM   #8  
josh1
they are using less asbestos? in brake pads... all of them will squeal except racing pads which are just too cold for normal driving ( most ). my .02... take off the pads and chamfer the edges slightly. If the rotors shot get it turned with an anti squeal pattern on it. ..still having trouble? you can get foil strips that help quell vibrations from the piston and pad never tried myself. Be sure to use some disc brake anti squeal lube when assembling all over the back of the pad. If you have concerns about brake dust go with EBC greenstuff pads ( might have to spec order) they barely dust at all on alloys. UK made. sweet stuff.

Hope this helps-Josh

 
robert smith's Avatar
Member

Join Date: Jul 2001
Posts: 323
IN

08-23-02, 05:39 PM   #9  
josh1

how would i know if the rotor is shot? they are brand new. do you think they got ruined by the pads or something and how would i know?

thanks

bob

 
josh1's Avatar
Visiting Guest

Posts: n/a

08-23-02, 06:02 PM   #10  
josh1
bob.. the rotor only wears by rusting/normal wear. Usually your manual gives a minimum thickness. You need a good set of calipers to measure them. As long as they are over the minimum they are OK. Now.. when i replace disk brake pads. I do NOt have rotors turned. I feel that new pads wont bed in well. So its a every other time thing. You can take and have the rotors turned if they squeal often. Also sometimes taking the corners off the brake pad helps. Sometimes on hot humid days theres nothing you can do. If the back of the rotor wont clean up under heavy braking it may warrant replacement. How rusty is rusty? surface rust is common if you dont drive for even a few days on rotors. But under normal driving this will wear away. If the intergrity of the rotor is in question Id replace it. Most arent too expensive. Hope this helps-Josh

 
robert smith's Avatar
Member

Join Date: Jul 2001
Posts: 323
IN

08-23-02, 08:44 PM   #11  
josh

here is the whole story, I don't know if you got it originally:

i replaced the front pads but the rotors seemed fine. then i noticed the back face of the rotors were very rusty and pitted. so, i replaced the front rotors as well and i reused the pads given that they were only on the car for about a week before i changed the rotors.

that is why i am wondering if rust got imbedded in the pads and that is why they are squealing. all four rotors, all sets of brake pads, and the rear calipers are new. i used anti squeal compound on all pads but they continue to squeal.

what do you think?

thanks

bob

 
josh1's Avatar
Visiting Guest

Posts: n/a

08-23-02, 09:29 PM   #12  
josh1
my .02... get a few cans of Brak Clean and be sure to clean the piston area in the front caliper. WHy were the back calipers replaced? I had one side frozen before on 2 piston calipers and they would squeal when I would go in reverse. Just an idea make sure the front calipers are working properly as they do most of the braking anyhow. Did the surface of the pads look pitted or worn when you switched them? If the pads look OK but still squeal. Take them out clean the caliper thoroughly (dont inhale brake dust its deadly) sometimes you can fit anti squeal shims between the piston and the pad. If after a thorough cleaning you still have the problem Id buy a new set of EBC greenstuff dustless (almost) pads.

PS did you replace the rear flex lines when you replaced the calipers?.. its a good idea as the hoses collapse as they get older internally.

Hope this helps-Josh

 
fordtech's Avatar
Member

Join Date: Jun 2001
Posts: 247

08-24-02, 11:31 AM   #13  
One thought i had was did you clean the new rotors before installalation?Many times they'll have a light coating to protect them while sitting on thre shelf.I'd do as someelse mentioned,clean everything real good with brake cleaning spray and lightly sand the pads.

 
dlalexander's Avatar
Visiting Guest

Posts: n/a

08-24-02, 04:35 PM   #14  
dlalexander
You might also try to coat the back of the pads (NOT the side toward the rotors) with some silicone grease. Several auto stores carry it in a tube form specifically for brakes.

 
Bill Locke's Avatar
Visiting Guest

Posts: n/a

08-25-02, 05:45 PM   #15  
Bill Locke
Brake Pad Squeal

I have found that the number one cause of brake squeal is greasy fingerprints left on the pads during installation. All of the above comments are good ones, but the ones mentioning the cans of brake cleanner I feel are the most important. I liberally spray the pads and rotors with brake cleaner and when I'm done they are quiet. You might even be able to get away with just spraying the rotors at this point, but it depends on how much greasy material are left on the pads. If there was a lot, removal of the caliper assembly will be required again, but you should be able to get away with not taking the pads out of the calipers.
Good Luck!

 
csmith4's Avatar
Visiting Guest

Posts: n/a

08-27-02, 02:22 PM   #16  
csmith4
thanks for the info so far.

i haven't tried anything yet. I am waiting until I have some time.

The noise is driving me crazy. It is definitely a metal on metal noise and is only coming from the front wheels. I did take them apart before I wrote this the first time and I cleaned everything real well with brake cleaner and I pulled out the pads and coated them with a good amount of anti squeal compound. They are still squealing.

any thing else you can think of? the rears aren't squealing and they are the same brands and rotors as the front.

the symptoms are that the front wheels squeal after a few minutes of driving and using the brake. the first few minutes they do not squeal. could it be heat related?

if you have some more thoughts, let me know. I am all ears!

thanks

bob

 
josh1's Avatar
Visiting Guest

Posts: n/a

08-27-02, 03:57 PM   #17  
josh1
bob

My thought is trash the cheap pads and buy something in the 50-100 dollar range. Cheap aftermarket pads on my MB almost got me into an accident. I switched them the next day. Its not worth the savings. -Josh

 
Search this Thread