74 -454 screaming brakes !!!!! Driving us nuts

[D@D74-454]

Hi all !!

Well we had all the brakes done on the car less than a year ago and they were never quiet all the time but have been getting worse. I must say that it is an embarrasment on cruise night. We are not too up on the problems with brakes on vettes but have heard they can be a real pain. I f anyone has had this and knows the best way to solve this problem we would really be greatfull. Also has anyone changed body mounts? If so was it hard to do and are there tips for doing it? Thanks in advance for any help.


Deborah and Dave

 

[Ala75Vette]

Don't know that 'loud' brakes is uniquely a vette problem. I replaced both front calipers (and pads) on mine, and now have the occasional 'squeak' but they're not bad enough to bother me. I did not replace/machine the rotors, because they were still pretty smooth. You might try the 'expensive' brake pads, make sure your rotors aren't pitted/grooved, and put some of that blue 'goo' on the back of the pads when you're putting them in (the parts store guy should know what you're talking about if you ask for it). I'm no expert, though, and vette brakes use the four piston calipers and high tolerance rotors, so hopefully some other experienced vette owners will post/address your noise issues, too....

 

[D@D74-454]

Thankyou for you're input

Appreciate the reply!!
I think I have seen the blue stuff you are referring to. It is supposed to quiet squeaky brakes right? We are pulling the whells off tomorrow night to take a look at the pads. I was told by a few vette owners that metalic pads don't work on these cars. I asked the mechanic what type he put on and he said not metalic so we will see.

Thanks again

 

[Tom Bryant]

This subject comes up every so often. One thing I have been told to try is greasing the pad pins. Some swear by it. I'm going to try it on the '81. It only has an occasional minor squeek but it seems loud outside the car.

Tom

 

[Bullitt]

Try using braking plate pads that mount in place of sticky blue goo. Most European cars use this soft pad to eliminate the squeal between caliper piston and pad. It works better because it has less tendency to stick the piston to the pad and wears less often.

Upgrading to higher compound brake material will lessen the noise of cheaper and less effective compounds. Most part stores will sell you a lifetime warranty with them also. I've always found satisfaction with using Perfromance Friction. I've heard good things about Hawk pads, too.

--Bullitt

 

[D@D74-454]

brakes

Thankyou for the advice. We will see what is available around here. We were told not to use metalic pads as they tend to screach more so than asbestes. Have you heard that?


Dave

 

[GW74]

My brakes were clicking, squeaking and driving me crazy.
I knew the rotors were not the problem as they were recently resurfaced.
I replaced the organic pads with a better quality semi metallic set.
I installed the adhesive backed anti squeak insulators that are available from MAD (9.99). I replaced the pins with the stainless steal ones. I also carefully applied some white grease to the pad leading and trailing edges and carefully inserted them into the calipers with out spreading it around. No more noise !

 

[wolf_walker]

The aqueak is a high pitch vibration of the pad the way I understand it. Excessive dust will make it worse. The goo or plates stuck on the back are a good idea, the dampen the pad's vibration and kill the squeak. They also make a specific grease you can get in little pacs for greasing brakes, it's really high heat stuff, you don't want to be hard on the brakes generating lots of heat and melt some grease onto your pads!

 

[Tom Bryant]

Also remember that pad manufactuers have a specific pad seating proceedure for new pads. If you follow this to the letter you will have fewer problems on down the road.

 

[Evolution1980]

Re: brakes

We were told not to use metalic pads as they tend to screach more so than asbestes. Have you heard that?
Dave

I'm no mechanic, but here's what I think I know...

Metallic pads do squeal more than asbestos pads. But from what I'm aware, there really aren't 'pure' metallic or asbestos pads. All the pads on the market are a percentage of each (if they still have asbestos at all in the pads). The more 'metallic' the pads are, the more the squeal due to the metal-on-metal contact. They are harder pads, but last longer. Softer pads have more organic material (formerly asbestos), but wear out faster.

As for not using metallic pads on vettes, I'd say that's bunk because a rotor is a rotor is a rotor. Whether it's solid, cross-drilled, or slotted, it's still metal. Exception: Porshe's ceramic rotors. It all comes down to what kind of breaking ability you want or need. (Or how much brake dust you care to clean up...)

On my Vette, I use Performance Friction pads which are moderately priced and decent performance, although I use super-expensive Mintex C-1144 Race Pads on my Contour. Different pads for different applications and driving styles.

The Vettes in general are notorious for squeaks other than the contact of pad-to-rotor. Like others said, the pins tend to squeak, as well as the back of the pads themselves. The grease on the pins shoudl only be enough to coat the pin or sleeve. You shouldn't have so much on there to worry about it melting and getting on your rotors. Same goes for the red anti-squeak stuff you put on the back of your pads. My Mintex pads came with the adhesive pads that you actually apply to the back of the pad itself.

 

[cntrhub]

I've been told at a GM training school, to use copper anti-seize instead of the blue type goop for brake sqeaks. Not only can you use it behind the pad contacts, but also a few dabs to the pins as well.
What I question is the disc finish? If they were turned, did the shop finish off with a cross hatch? Look at the surface of the disc. Is there a cross hatch finish or just lines that like an old 45 rpm record? Also, are the discs within specs as per thickness?Usually there is a "break out" spec in millimeters cast in the disc. Too thin a disc can set off a ringing noise. Think of it as, wetting your finger and then circling around the top of a wine glass to creat that sound.
Go look at a new OEM brake disc and see what the finish looks like out of the box. Or drive by a new car dealer and peak inside the front wheel and see if you can see the disc on a new car. This is what the disc should look like after the disc is turned and the 60 degree cross hatch finish is applied.
Were the brake pads "burnished-in?" After disc truning and final cross hatch finish, I would take the car out and apply the brakes harder than usual to bed in the pads. Pull the pads. Are there high spots? Is the pad making full contact? Does the wheel turn free when there is no brake pedel pressure? Are the caliper pistons hanging up causing excessive drag?

 

[GW74]

Cntrhub,
How exactly do you apply the anti sieze to the back of the pads? Just where the calipers touch I assume and not too thick.

 

[cntrhub]

Correct. Just the contact points. Any place else is a waste of product. Look at the old pads. Notice where the contacts are worn and apply the anti-seize to the new pads at these locations. You will notice the two shinny spots on the pins also.
Apply enough anti-seize to the contact points that you are sure you won't have to remove them to see if you hit the right spots. A little goes a long way.