Park Brake Adjustment

[70camaro]

I know this is kind of a lame question BUT...
How do the rear drum park brakes self adjust on a leading-trailing drum break set up? I've read it is when brakes are applied when moving in reverse?
I replaced my shoes and that went fine, but now I have no park brake!
HELP!
BTW, 97 GMC 1/2 ton 4x4

[2000CAYukon]

Yes they only self adjust going in reverse. When doing brakes, I adjust them so that there is some drag before putting the wheel on. If you don't feel any drag at all, the parking brake will probably not work.

On my 90 GMC K1500, there is no slot in the back to adjust the rears with the wheel on. I also adjust the brakes every tire rotation since the self adjuster really do not that good of a job.

//2000CAYukon

[Chevy-SS]

My first question is - are your rear brakes actually working? Did you adjust them prior to installing the drum?

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[70camaro]

Hmmm, good question... They are contacting. I know because I had my wife step on the brake to hold the wheel while titening the lugs
I guess i better pull those drums off and adjust that wheel manually, bummer.

[herkyhawki]

Do Not adjust the brake shoes to get the parking brake to engage.
Adjust the adjusment link on the Parking Brake cable. Follow the cables forward from the drums and you will find an adjustment link. turn bolt/nut to adjust parking brake.

[Chevy-SS]

Originally Posted by herkyhawki

Do Not adjust the brake shoes to get the parking brake to engage..........

?????? The very FIRST THING that he needs to do is adjust the brakes properly.

After that, he can adjust parking brake cable as needed.

[J-Ri]

They only adjust going in reverse the first time you stop in reverse after going forward, so driving backward for a mile and hitting the brake 100 times won't do more than hitting it once.

Also check to make sure everything is in place while you have the drum off to adjust them. And do adjust them, Chevy-SS is right it's the FIRST thing you do... If they worked before you did the brakes and don't after (and if you didn't loosen the adjuster... for... some strange reason ), it's obviously not out of adjustment in the cable.

Also, I'm going to assume that you didn't machine the drums (only because that makes what I'm about to say possible), the rust lip on the edge will make it very difficult to adjust them up and still be able to fit the drum back on. If that's the case, have them machined or buy new. At the very least grind the lip smooth. On my own vehicles, I taper it slightly (starting where the lip starts) so they are easier to remove in the future.

[Chevy-SS]

Originally Posted by J-Ri

......the rust lip on the edge will make it very difficult to adjust them up and still be able to fit the drum back on. ....At the very least grind the lip smooth. On my own vehicles, I taper it slightly (starting where the lip starts) so they are easier to remove in the future.

Great tip! I grind mine every time.

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[2000CAYukon]

Originally Posted by J-Ri

They only adjust going in reverse the first time you stop in reverse after going forward, so driving backward for a mile and hitting the brake 100 times won't do more than hitting it once.

I don't agree with this statement. How do the brakes know this is the first time you are stopping in reverse?

See http://auto.howstuffworks.com/drum-brake2.htm

//2000CAYukon

[Chevy-SS]

Originally Posted by 2000CAYukon

I don't agree with this statement. How do the brakes know this is the first time you are stopping in reverse?

See http://auto.howstuffworks.com/drum-brake2.htm...

The rocking motion (as the whole assembly is shifted while going from forward to reverse) will facilitate the adjuster action much more effectively than just driving in reverse and hitting the brakes 100 times.

Regardless of which way is actually more efficient, this is certainly NOT the proper way to adjust brand new brakes.

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[J-Ri]

Very nice answer, almost word-for-word what I would have said, BUT, I was not suggesting that the brakes be adjusted by means of the automatic adjuster, I was only adding on to the "brakes only adjust in reverse" statement by 2000CAYukon. I had this vision of someone somewhere driving around their neighborhood backwards for half a day wondering why they still don't have a functioning parking brake system

[2000CAYukon]

Originally Posted by J-Ri

Very nice answer, almost word-for-word what I would have said, BUT, I was not suggesting that the brakes be adjusted by means of the automatic adjuster, I was only adding on to the "brakes only adjust in reverse" statement by 2000CAYukon. I had this vision of someone somewhere driving around their neighborhood backwards for half a day wondering why they still don't have a functioning parking brake system

The first post asked how the self adjusters work. I never suggested driving backwards for half a day. The fact is that they only self adjust when the vehicle is in reverse.

Perhaps, I miss read you post. If someone went in reverse, hit the brakes, drove forward, stopped and then went in reverse again, repeat. This would actually adjust the brakes as far as the self adjusters will adjust. It is not very efficient but would work.

//2000CAYukon