1962 GT Hawk Brake Squeal

[56GH]

I had my entire four-drum brake system on my 1962 GT Hawk replaced with a kit from S-I: new drums (one old one was machined 0.090" over!), shoes (new on the front, rebuilt on the rear), wheel cylinders, master cylinder, seals, hoses and studs. Now I have a squeal that seems to be coming from the right front wheel when I apply the brakes firmly (both forward and reverse). The noise isn't there with light braking , just when the pedal is down hard towards the end of travel. There are no rubbing sounds otherwise and the shoes are adjusted to a good firm feel using the Shop Manual instructions.

As an aside, and I don't know if it's relevant, but the reputable mechanic who did the rebuild told me he used the old brake springs because he felt the new replacement springs were "too stiff." The old brake shoes didn't look that bad except for the right rear that was locking up on hard braking, but I had the whole system done anyway. So I've got all the new springs left over from the S-I kit.

I've done a Forum search and couldn't find anything addressed to this particular problem. Any ideas from anyone as to what might be causing the squeal? I'd appreciate some advice as to what to look for before I tear the right front wheel down.

Thanks.

[JoeHall]

As long as it stops well, and reliably, I would give it at least 500 miles of town & country driving before trying to fix it it. As miles go by, the source of the noise may also become more evident, i.e. a related, "feel" in the pedal. Then too, the noise may lessen, or go away after a few hundred miles.

[56GH]

Thanks very much for the advice, Joe. With the way I drive, I'll have to be patient because I probably cover only about 500 miles a year with my GT!!

[StudeRich]

Probably THE most common cause of drum brake Squeal is the ENDS of the Lining not being beveled, if they already are, then the Chatter has another cause, maybe an out of round Drum.
Yes I know they are New, that does not always mean Perfectly ROUND after the Hub is installed.

[az64stude]

Does the car stop straight? How many miles have you put on these brakes?

[56GH]

Rich:

They don't chatter. They're nice and smooth in application. They just squeal.

- - - Updated - - -

The GT stops straight. I've got less than 50 miles since installation.

[StudeRich]

Ok, so were the Lining ENDS BEVELED?

[GrumpyOne]

I recall having the linings replaced on my T-Cab, (at the time), and it was just as the non-asbestos linings were going out. Well the new linings squealed from day one all the way through to a trip back east with a stop in South Bend for an international meet. I remember Jeff Rice remarking that they could hear the truck from a quater mile away.

Anyway, it took about two years for the brakes to quit sqealin' and about 10,000 miles. They worked perfectly otherwise...

[56GH]

No, they weren't. S-I sent them to the installer without beveling.

Ok, so were the Lining ENDS BEVELED?

[56GH]

Hard to tell at this point, but MAYBE I've solved the squealing problem -- and in an unexpected way! Using Rich's idea about the beveliing, I pulled the drums off the front wheels today and found that the shoes from S-I were not beveled. So I beveled them myself (not as much as you see in the factory Shop Manual.) But in beveling one end of the primary shoe on the right front, I found a non-uniform acccumulation of very small diameter copper wires that were molded into the lining matrial (to improve wear and increase friction?). It may have been the copper wires that were squealing against the cast iron drum. Anyway, most of the squeal is now gone.

Thanks to all for the suggestions everyone.

[56GH]

As a follow-up to my squealing front brakes issue, the more I used my Hawk, the squealing noise came back and then the brakes developed a chatter. I tried beveling the edges of the shoes, adjusting the brakes over and over again (definition of insanity?), and replaced the old springs with the new ones from S-I. Frustrated, I contacted S-I and they sent me another pair of shoes, this time they were rebuilt and not new ones. After careful examination below, you can see that the new shoes that I took off have small brass particles imbedded in the lining material. It was probably these what I call "semi-metallic" shoes that were causing my problems. They're also glazed over and have chatter marks on them. The rebuilt shoes are now installed, stop well and are noiseless! Jim at S-I was very helpful.

[bezhawk]

I thought they were going to eliminate any copper in brake lining material? It seems the brake dust run off is poisoning streams near highways, and the culprit was copper.

[Bud]

I'm glad that I have a good stash of older Bendix brake shoes, and not the non asbestos ones as I haven't had very good luck using the new style linings on cars that weren't designed to use it. I've never had problems with brake squeal or chatter from the brakes in the 42 years I've owned my 62 GT. Bud

[harry]

Shouldn't brake shoes be arced to match the drum, not just bevelled?

[TWChamp]

Shouldn't brake shoes be arced to match the drum, not just bevelled?

I used to do that when I worked at the GM dealership, and at the auto shop, but haven't done it for many years. I find they are so close, and I always brake easy, so they wear to the full contact before too many miles. Hard braking during the break-in period, of about 1000 miles, can lead to grooves in the drums. The second Studebaker I bought in 1969 had some deep grooves in the drums.