New Brake System Problems

[snowborder714]

I just got finished installing my new brake system. I got new Powerslot rotors all around with Axxis Metal Master Pads. I upgraded my front calipers to GSX 2 piston ones and rebuilt all 4 calipers. I got all new SS lines from RRE as well. I also painted the calipers. I have 1 shim on each rear pad and 2 shims on each front pad (as they came from Mitsu). When I took it around the block last night, it sounded like the rotors were rubbing against something (maybe the pads?). I'm not sure if it was all of them or just a few. Why would this be happening? I'm pretty sure the pads came preshimmed but I read somewhere else to put the other ones on anyway to keep the noise down. Might this be causing it? I'm not sure if it's the pads rubbing or not. I did also replace a few control arms and the driver's side axle, if that might do anything. I'm really not sure what would be doing this. Any help would be appreciated! (Preferrably quickly as I haven't driven the car in over a month and really want to! )

 

[asexton6969]

It's definately a possibility that you shimmed too much. Remember they need to retract enough that they won't touch the rotor. For future reference, O'reillys carries ThermoQuiet brakes. The shim is molded into the pad, so you dont even have to worry about it falling off or having to add a shim. If you think the pad is rubbing the rotors, try removing a shim at a time. Unless you feel that the noise is not a brake grind? Let us know.

 

[turbosax2]

I'm snowborder714's brother. If we removed 1 shim from the front brake pads should we remove the metal shim or the rubber coated one? And the Metal Masters have a shim molded into the pads too but one thread we found said to still use separate shims.

 

[asexton6969]

Remove the metal one. I would remove both shims off the front. If a shim is already built in you should be ok. Let me know if you have any other issues.

 

[snowborder714]

We just jacked the car up and it's making the grinding noise from the pads/rotors. We're going to try and take the shims off and see what happens. Thanks so far and if anyone else has any experience with this, let me know!

 

[snowborder714]

We took off all the front shims, drove it around the block, put it back up on the jack, and spun the tire by hand and I'm still hearing a bit of scraping sound. Not nearly as bad as before though. Might the rotors and pads not be seated all the way? I haven't broken them in yet (with the instructions Powerslot sent to me).

 

[snowborder714]

We took off all the rear shims as well now. They do spin a bit better (when the car's up on the jack) but not fluidly if they're supposed to. I did talk to a friend who's going to school to become a mechanic and he said there will always be pressure on the pads to the rotors because of the way the calipers are designed. He also said that since the pads are new, they are probably really thick so they will need to be ground down a bit. I also found this from Edmunds:

"Sometimes, with new brakes, you can get some weird scraping and scratching sounds; these will usually go away in a few days."

Here's the link: http://www.edmunds.com/ownership/howto/articles/43787/article.html

Any one else have this sound/issue?

 

[asexton6969]

If you guys haven't broken in the brake pads. Definately go ahead and do so. I would suspect that it will be much easier to get rid of the noise without all those shims on their as well.

 

[turbosax2]

We're going to go ahead and break them in tomorrow then. All of the shims are removed now. Thanks for the help and we'll keep you updated!

 

[toybreaker]

I usually manage to bend at least one backing plate during a major suspension/brake service. The backing plate gets really close to the front rotors at the bottom, (to provide clearance for the ball joint,) and it doesn't take much to bend it into the rotor there.

Give it a hard look to eliminate the backing plates as a cause

 

[Locke]

Remember they need to retract enough that they won't touch the rotor.

On disc brakes, the pads should always be in contact with the rotor. This prevents water and road debris from getting between the pad and disc.

Drum brakes are the ones that require the shoe to not contact the drum while at rest, otherwise a shoe would tend roll into the drum. (grab)

 

[snowborder714]

Give it a hard look to eliminate the backing plates as a cause

Do you mean the dust shield?

 

[turbosax2]

Also, we adjusted the parking brake about 2 weeks ago by the directions in the Chilton's manual. Even though we adjusted it properly, could it still be holding onto the rear rotors a bit? And is there any way to check to make sure the caliper pistons are retracting enough like they should be (although I don't think this is the cause because we just rebuilt the calipers)?

 

[toybreaker]

Do you mean the dust shield?

Yes.

 

[turbosax2]

Yes.

We checked all of them and they looked fine - weren't touching at all. I'll make sure to double check again when I get home.

 

[turbosax2]

Ok I just checked the front brakes - I took the pads out, put the caliper back in place, torqued the wheel down and then spun the wheel - it spun freely. So this means the pads are definitely what is rubbing on the rotors. They aren't hitting the dust shields.

My brother got new guide and lock pins from Beck Arnley and I noticed they're the tiniest bit longer than the stock ones. This shouldn't make a difference, should it?

 

[asexton6969]

What's tiniest? Is there anything wrong with the old slide pins? As long as they are greased they should be fine.

 

[turbosax2]

The new slide pins are slightly longer (very slightly) than the stock pins. Nothing is wrong with the old slide pins, we just decided to replace them since we replaced everything else. I don't think the very slight size difference should matter though. Does it?

 

[turbosax2]

Well, even though we adjusted the parking brake per specs it still sounds like it is slightly scraping the inside of the rear rotors. All of the rotors are still being rubbed against by the pads. We are hesitant to go through the break in process with the brakes because we obviously don't want to ruin anything in the process. Please, if anyone else has ideas or can help, it would be much appreciated.

 

[DoyoFCT]

i'd like to see some pics... of the brakes with the wheel off.

 

[turbosax2]

i'd like to see some pics... of the brakes with the wheel off.

I'll post them when I get home. If anybody needs more info, pics, videos to help us out just let me know.

 

[turbosax2]

Well I took the car to a mechanic yesterday and he couldn't put it up on his lift because the car was too low. Just by looking at the brakes though the wheel he said they looked fine. Then we took it for a test drive so he could hear the noise I was hearing. He thinks it's a wheel bearing. So now we have a new problem........ Thanks for the help though!