About 4 weeks ago I replaced my front brake pads. The new pads had a shim built right on the back of each pad. Seeing this, I didn't use the stock shims that were on the old pads. Should I have installed the stock shims even though the new pads already had shims built on the back of each pad?

What prompted this question is the fact that my brake pads are slightly rubbing against the rotors. I can hear it with the windows down and making a turn. When I installed the new pads, I smeared that anti-squeal stuff on the back of each pad and placed them in the pad clips. After hearing the pads skimming the rotors, I thought the calipers were bad(129k miles), so I installed rebuilt calipers yesterday. With each caliper came new slide pins, rubber boots for the slide pins, pad clips and bolts. I used anti-seize compound to lubricate the slide pins and the notch in the pad clips. With everything assembled, I still hear the pads skimming against the rotors. So now, it's either install the stock shims over the new pad shims and/or my rotors need to be cut. Brake pedal does not pulsate so I'm not sure about the rotors. Any ideas??

 

You were right not to install the old shims over the new ones. There is no need to install both and this would not cause your problem. Usually rubbing pads are caused by insufficient lubrication of the pins or the nothces where the pads slide into the calipers, but it seems that you covered that base. Did you remember to put the two wire springs back on?

If you only hear it when you are turning, then chances are that you are have more of a problem than sticking pads. My guess is that it is one of two things.

1) Maybe there is some kind of debris in front of or behind the rotor and/or calpier that is not allowing them to seat properly so when you turn the rotor or caliper is shifting causing the rubbing

2) May be what you are hearing is not the pads rubbing at all. I would look all over the wheel well and steering/suspenion areas and look for signs or rubbing

 

Yes, I remembered to install the pad return springs. I know that the pads are rubbing because it stops when I apply the brakes. I have a copy of the shop manual and it shows an inner shim and shim cover on the piston side pad. I was wondering if I should have installed the shim cover??

 

that happened to me before, just like it, i waited about a week and it went away, but i remember doing a hard brake once and a few mins later, i didn't hear it again.
good luck, try doing what i did, and if that doesn't work, i have no idea why it is making that noise.

 

I had the same thing a while back, except for me it looked like the torque member was scraping the rotor. It turned out that the center hub nut worked its way loose and allowed play in the hub and wheel bearing. I ended up trashing the wheel bearing and hub, was about $400 total. So take the wheel off and check for play in the hub.

 

Make sure to use just enough grease on the caliper pins. Too much grease can cause trouble. The pins should be able to move in and out easily. If they have a tendency to pop out, then air is trapped inside (too much grease).

 

it could be your hub and bearing. cleammax had this problem and it was his hub bearing assembly. had it replaced, and noise whent away.

 

What's the purpose of those V shaped pad return springs anyway??? I haven't run on my pads for years. Or do they just hold the retainers, which I don't have either.

 

I guess they help push the pads back against the caliper after the brakes are released.

 

if the pads didnt come with the shims dont worry, as long as you put the brake pad lubricant youll be okay. other than that it sounds like you did everything right as far as the installation. you said the rotors might need to be cut, this leads me to ask...

did you cut your rotors when doing your brake job? if you didnt then please do so, that might just be it. if you did, dont take it offensively im just trying to help. if you hear this noise in the morning and it goes away during the day its just rust that builds up on the rotor from humidity its normal its okay happens to every car. if you hear it all day and it stops only when you brake check your hubs/bearings. jack up one of your front wheels and try to movew around the tire in and out of the wheel well. if theres more than just a few MM's of play thats your problem. if your not sure take it Sears auto they do a 45 point inspection on the chassis including brakes for FREE!!!!


good luck

 

disc brakes will always drag slightly, but if you jack up the tire and its tough to spin it by hand when in neutral, then thats excessive drag...

 

I'm replacing pads and rotors soon....and wondering if high emperature grease could be used on teh back of the pads in place of an anti-squeal compound? If not, what should be used ? Also, what is recommended for the caliper slide pins....anti-sieze or high emp grease? Thanks

 

I have had no problems using shims and just adhesive. (one or the other, not both)

I never use anything but synthetic caliper lube on the pins and backings, NEVER use anti-seize, not the right application for brakes.

 

I just did mine and used syn caliper grease on my pads and shims as I thought we weren't supposed to use anti-squeal.

 

Isn't the anti-squeal stuff more like an adhesive rather than a grease. The Permetex stuff I bought was sticky, not greasy.

 

I took a look at the front rotors this morning and I can see where the pads are rubbing. On one side, the rotor has a brownish looking ring from the outside edge to about 3/4s of the way down. From there, there is a smaller ring that is very clean looking. On the other side, there is a very light blue ring starting from the top edge down towards the center. So now, I'm not sure what to do. I'm leaning towards new rotors, but first I may clean off the anti-seize compound from the caliper pins and from the hole that the pin slides in. I will then apply some hi temp grease and see what that does. Any ideas??

 

Definately get that anti-sieze off the pins and use caliper grease. Try to extend the boots out as much as possible and get some air inside the pins to keep em from compressing too much. (I think).

 

If you can see colours like 'light brown' and 'blue' on your rotors, they have been running at extremely high temperatures - those colours are what we use when tempering steel to a specific hardness!
I'm surprised you haven't managed to boil the brake fluid. If by chance you have noticed a 'sharp' smell, then that's what was happening. Boil the fluid and you'll lose the brakes completely because vapour, unlike fluid, is compressible.
In other words, *** danger! *** better fix it well, before driving it again.

 

I agreed totally, but check also to make sure you put enough grease. I read that you used anti seize on the caliper pins. I'm pretty sure you should have used grease. Just take them out, check them. If they are dirty, clean em' and put new grease. From then it should be fine. or do that SEARS thing...the guy has a point

 

Last Thursday, I cleaned all of that anti-seize compound from the parts that I had applied it. Applied high temp silicon grease to slide pins and pad clips. Took it for a test run and it still was rubbing. So I dropped the car off at my mechanics garage and he found that the rotors were warped and that the new pads were scraping the rusty part of the rotors. So he cut the entire width of the rotor. He said that the only time he heard it rub was when he was making a turn during his test drive.

 

I went to the local Levine Auto parts place to buy some anti-seize compound for the brake job I am doing this weekend. They had a bunch of kinds.

One was an electrical compund. Basically, a synthetic grease with lots of ground up copper in it. The guy said at one time this was all you could buy and that they dont actually cary it anymore. Its just old stock.

There were two others, again both were grease with either copper or nickle flakes in it.

Then there was one which was dielectric for disimilar metals.

And last but not least was the source of confusion. A combination Caliper Grease and Anti Seize compound.

I bought the old electrical stuff having recognized it from my days as an electrican.

I have caliper grease left over from the last job.

Somebody said you can buy a red colored caliper grease. Anybody know where that comes from?

 

I don't use anything besides CRC's caliper grease myself.
http://www.crcindustries.com/auto/co..._ss.aspx?ID=64

 

I'm a little confused. I always thought that the anti-squeal stuff was applied to the backs of the pads. I've been seeing that some people apply hi-temp silicon grease to the backs of the pads. Which way is correct??

 

The anti squeal stuff is correct.

There are, as I can tell, three specific compounds needed in brake work.

Anti Seaze Compound for between rotors and hubs and hubs and wheels etc.
Caliper Grease which is some sort of high temp grease for lubricating caliper pins. And this liquid rubber stuff (anti squeal compound) which is like a high temp silicone glue that dampens vibration.

For my upcoming brake job I have so much crap-in-a-jar.. it looks like a drug lab or something.