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scalemechanic
09-07-2011, 04:29 PM
I have a 2000 SL2 with about 114,000 miles. When i first bought it about 2 yrs ago it had about 100,000 miles and among many other things it needed was new roters, pads and one caliper. These were the worst i had ever seen. So i replaced them and all seemed well for a long time.

Recently i started getting the metal to metal scraping sound again, so upon inspection i found both roters gone, at least one of the calipers sticking and both pads in bad shape. Some of this was lifetime warrenty so the new cost was under 100 dollars.

Anyway i installed the parts but i am getting a scraping sound on the drivers side brake and cannot figure out why. It sounds like the pads are not retracting after i take my foot off the brake. I reckecked the slider bolts (new) and added grease to them and to the inside of the boots. The shiney metal brackets they slide on are also new and i also put a touch of grease on those. I'm still getting the scraping sound.

Over the years i've replaced many disc brakes on other cars i've owned and never had this problem. Any idea what might be causing this??????????????

brags
09-07-2011, 06:58 PM
with-out seeing it i would guess caliper not retracting fully. brake
caliper could be your problem. have you jacked up the drivers side
and spun the wheel ? and if so does it turn fairly free ? when you
hear this sound is it during braking ? after braking or always there ?

2NDSOUT
09-07-2011, 07:00 PM
What were the conditions of the top and bottom caliper pins? I have found out from experience to just replace the caliper pins everytime I do a brake job now. A few years back, I had one of my caliper pins stick and it got stuck in the upper metal sheath. Caused the caliper piston to stick and smoke as well.

Maybe the scraping sound is not from your brakes. Maybe it is a worn wheel bearing on the driver's side..? Just something to think about.

scalemechanic
09-07-2011, 10:29 PM
brags and 2NDSOUT. The scraping goes away when i apply the brakes.

The caliper pins are brand new as are the guides they ride on. Also both calipers are brand new as are the pads.

I usually hear this sound after removing my foot from the brakes and cruising along. As you said, it's like the caliper is not retracting. Any other ideas????

The only other thing i can think of doing is to either to put the old caliper pins in the new caliper or remove the new pins, clean the grease off, maybe sand them down a bit and put a lighter grease on them.

2NDSOUT
09-08-2011, 07:18 AM
Please don't take this as an insult... but is it possible that maybe the pads were installed backwards?

I have made this mistake before when I first was learning how to do brakes... maybe take a look at the pads and make sure they are seated properly and not installed backwards.

Highmile
09-08-2011, 08:13 AM
Please don't take this as an insult... but is it possible that maybe the pads were installed backwards?

I have made this mistake before when I first was learning how to do brakes... maybe take a look at the pads and make sure they are seated properly and not installed backwards.

This is actually easy to do, I've seen it done a few times.

The other thing is that the rubber hose that goes to the caliper can colapse internally. They will look fine but will not allow the caliper to release.

Good Luck
'95 SL1 463k and counting

scalemechanic
09-08-2011, 01:04 PM
If it stops raining tomorrow and before i pull the caliper pins, i may put the front end of the car up on jackstands, start the car and let it run in drive to see if i can see what is making the noise. i'll hit the brakes, release them, turn the wheel etc.

The pads are not on backwards but one thing i was unsure of when installing them was, does the rounded clips attached to the pads (looks a bit like wear indicators but face away from the pads and rotor) go toward the top or bottom or does it make any difference?? I'm not sure why they're there but my old pads also had them.

2NDSOUT
09-08-2011, 01:24 PM
http://i00.i.aliimg.com/photo/v0/301618138/D728_GM_Saturn_Brake_pads.jpg

In the above image, the part with the markings is the part of the pad that should be facing towards the Caliper Piston on both sides.

Those anti rattle springs that stick out, I have always put those towards the bottom of the caliper itself.

The marking part should have a generous portion of the following added to it to reduce brake noise, the CRC Brake Grease. I have not used the brake quiet stuff before...

http://files.subtledream.com/forum/brake_grease.jpg

The CRC brake grease is available in a container with a brush. I usually put this on the exterior side of the brake pads as well as coating the caliper pins, so it is easier to remove them all the next time I do a brake job.

blue92
09-08-2011, 01:27 PM
Have tried using , 'CRC disc brake quiet', when installing the pads?
If the pads are loose, they will not always pull back, and lightly rub against the rotor, causing them to squeal.

2ndsout, beat me to it! :ugh:

2NDSOUT
09-08-2011, 01:42 PM
Have tried using , 'CRC disc brake quiet', when installing the pads?
If the pads are loose, they will not always pull back, and lightly rub against the rotor, causing them to squeal.

2ndsout, beat me to it! :ugh:

It's all good blue ;)

scalemechanic
09-08-2011, 04:05 PM
All good info. I'll get some of that Brake Caliper Grease tomorrow. I'm not sure if it made any difference but i used regular black multi purpose grease on the caliper pins and the back of the pads.

I'll also remove and reinstall the pads so the anti-rattle springs are toward the bottom. All along all the pads have faced toward the rotors.

rcw3586
09-08-2011, 04:30 PM
One thing I found is that the calipers tend to build up rust around the nubs which retain the sheet metal pad mounting clips (sorry - don't recall the formal name). The rust causes the slot that the pad ends ride in to close up a bit and bind the pads. By wire brushing and filing the rust away I have solved that problem.

brags
09-08-2011, 06:36 PM
This is actually easy to do, I've seen it done a few times.

The other thing is that the rubber hose that goes to the caliper can colapse internally. They will look fine but will not allow the caliper to release.

Good Luck
'95 SL1 463k and counting


highmile i have heard of that happening before too. You are right about
the rubber hose colapseing internally and sometimes depending on
how they colapse inside you can even get one to act as a 2 way
check valve :yes: rubber brake hoses are cheap to change.

scalemechanic
09-09-2011, 03:56 PM
Because my adult son is moving out tomorrow (finally) i haven't done any more yet on this problem but i do have a REQUEST before i get back into it.

I've read on some other posts while doing a search that it's possible to reinstall the rubber hydraulic hose on the caliper, facing the wrong way thereby causing a scraping noise. Could someone post a picture of how it should look when properly installed??? I just want to be sure i have that right.

As some of you mentioned it may also be a collapsed hose. I'll get into that if nothing else works.

Thanks

scalemechanic
09-16-2011, 09:36 PM
Well i got back on this job today and i think i may have found the problem.

While removing the top caliper pins i noticed they were very hard to unscrew. I found they were being restricted by the rubber boot they go into. It seems the top boot has a sleeve that completely covers the slide pin. The pin and the boot will not easily fit into caliper slot thereby causing it to bind up.

So i cut that part of the boot off leaving just the part that covers the exposed portion and about one quarter inch into the hole. I left the bottom boots as they were, as they only cover the exposed portion. I also cleaned the old grease off all the pins and put some anti-seize grease on them.

I have not seen any info on this situation anywhere and i wonder why the top pin comes with a boot that completely covers it. I bought these at AZ and they were just like my previous ones that caused a lot of problems because of the top boot which i left on.

I also installed new brake hoses, so everything in that area is now new. I'm going to bleed the brakes tomorrow and see how it all works.

In the meantime, if anyone knowns the purpose of the full boot on the top pin, please let me know. Thanks

Bernie
09-17-2011, 10:26 AM
I've read on some other posts while doing a search that it's possible to reinstall the rubber hydraulic hose on the caliper, facing the wrong way thereby causing a scraping noise. Could someone post a picture of how it should look when properly installed??? I just want to be sure i have that right.

I think I know what you may be referring to. My daughter was getting a scrapping sound during hard turns soon after she had a local mechanic do her brakes. Upon inspection, I noticed that the caliper was turned around causing the hose to rub on the tire when the wheel was turned to the stops. What I presume happened is that the mechanic tied the caliper out of the way and accidentally twisted it around upon re-installation. That caused the hose to loop toward the tire rather than away from it.

2NDSOUT
09-17-2011, 01:12 PM
Well i got back on this job today and i think i may have found the problem.

While removing the top caliper pins i noticed they were very hard to unscrew. I found they were being restricted by the rubber boot they go into. It seems the top boot has a sleeve that completely covers the slide pin. The pin and the boot will not easily fit into caliper slot thereby causing it to bind up.

So i cut that part of the boot off leaving just the part that covers the exposed portion and about one quarter inch into the hole. I left the bottom boots as they were, as they only cover the exposed portion. I also cleaned the old grease off all the pins and put some anti-seize grease on them.

I have not seen any info on this situation anywhere and i wonder why the top pin comes with a boot that completely covers it. I bought these at AZ and they were just like my previous ones that caused a lot of problems because of the top boot which i left on.

I also installed new brake hoses, so everything in that area is now new. I'm going to bleed the brakes tomorrow and see how it all works.

In the meantime, if anyone knowns the purpose of the full boot on the top pin, please let me know. Thanks

I would venture to say that the full boot on the top is the fact that the top caliper pin is fatter, and that it goes into a full metal sheath- to keep alot of the dirt and grime from getting in there. I have had top caliper bolts shear off on me before; hence the reason why I change them now with every brake change. Alot of heat in that area is transferred around, and I have even had to take a mini-blowtorch to heat up the top caliper bolt until it was almost cherry red to get it out before.

Bernie
09-17-2011, 05:05 PM
I have had top caliper bolts shear off on me before; hence the reason why I change them now with every brake change. Alot of heat in that area is transferred around, and I have even had to take a mini-blowtorch to heat up the top caliper bolt until it was almost cherry red to get it out before.

That sounds odd. I've never had a car where the bolts were that difficult to get out. Perhaps the rubber sleeve leaked and the bolt corroded.