67, Powered drum brakes all around.

I just had the car inspected, and they told me the front brakes differ more than 30%, the rear brakes are good.

Tried the reverse procedure, but no joy.

So I need to pull off the drums and do a manual adjustment, right? That looks like a fairly straight forward procedure.
Do I need a special tool to pull the drums off, or can I use a regular puller?

Are there any other likey reasons why the brakes are uneven?

You may have to get the drums turned or replace, and also replace the brake shoes and the hardware kit. It just makes it easier to eliminate a problem, then bleed the brakes, check for a bad brake cylinder why your at it (you will see a leak if its bad enough)..

The brake will differ from front to rear, and they do sell at tool (kinda like a bent screw driver) that you can slide in to the back side of the backing plate hole (there may be a rubber plug here) and then you would adjust the adjuster.

A better way for you to learn on how it works, would be just take the rim and drum off (you may have to use a rubber mallet) this will help you get the drum off. If it gets stuck then you will definitely have to get behind the backing plate (take the rubber boot off) and loosen it up.

If you get the drum off, then adjust the adjuster to expand the brake shoes until the drum can slide back on with very little resistance. Then take it out for a test drive and hit the brakes hard, see if the car will stop straight or if it pulls to the left or right. If it pulls to the left or right, then check your adjustments again. Worst case would be that you will have to do all the above with all new parts.

Also you can look under the forums under brakes, search for drum brakes.

 

It's been many many years since my Camaro had drum brakes, but I'm pretty sure you have to punch out a hole in the drum to do any manual adjusting. There is no hole in the backing plate like older cars have.
You may have a stuck adjuster. If the drum is worn a lot, it may not come off without backing off the adjuster.
David

 

67, Powered drum brakes all around.

I just had the car inspected, and they told me the front brakes differ more than 30%, the rear brakes are good.


Are there any other likey reasons why the brakes are uneven?

I think this refers to a side to side variation. If so it might be caused by two different sized drums, like might happen if one drum was "new" unturned and the other was turned out to the limit. I thnk I would replace all of the hardware inside there if it is at all questionable. I have seen wheels cylinders stick so that both pistons are not pushing. We used to check with drum off, one guy watching cylinder another lightly pushing pedal. Sometimes helps to hold one shoe by prying with a screwdriver.

Jeff

 

The 30% is between the left and the right front wheel.

I'm going to take the drums off anyway, so I can get a good look at the whole brake assy. So a few whacks with a rubber mallet should be enough to get the drums off?

The service manual says to take the drums off, measure the diameter of the shoes and the diameter of the drum, then adjust so you get a specified clearance. Or you can adjust so the brakes drag slightly, then back off a bit.

It all depends on how much the drums have been worn, but I won't find out before I take the them off.

Thanks!

Note to self: Buy a rubber mallet.

 

"Note to self: Buy a rubber mallet."

Edit note to self: "Buy a rubber mallet, a small baby sledge hammer, case of beer, and invite friends over"

Sometimes drums are a major pain in the buttkus to get off, and a rubber mallet just won't get it done.

Don't be afraid to upgrade your hammer choice

Jim

 

just be careful not to hit the studs when doing the hammering. if they pop out, that's not a big deal- but if they break off or you screw up the threads, that is kind of a big deal.
how many times did you try self adjusting them by going in reverse? how fast were you going, and how hard did you slam on the brakes? sometimes, you gotta do 5-10 HARD stops from about 15mph before things start to get properly adjusted. yeah, people will think you are an idiot for constantly slamming on your brakes in reverse on the street or in your driveway, but that's just part of being "that weird car guy in the neighborhood".

 

Note to self: Buy a lot of beer.

 

Interesting! I just let it roll backwards at maybe 5 mph, then hit the brake not too hard.

I'm going to take them off anyway. I feel the need to have a good look just to see if I maybe need some new drums, or if the previous owner overhauled the brakes when he did the rest of the car.

 

Elf....There's really no need to do the reverse adjustment if you know how to properly adjust the self adjusters!.....The brake drum must slide over the shoes semi tight, but not too tight to the point where it becomes difficult to remove.....You must get both sides the same or it'll pull on braking.....At this point the self adjusters will be adjusted and there will be no reason to perform the reverse adjustment!.....Does beer in your land taste as good as ours here in the United States of America?

 

it's still a good idea to let the self adjusters do their job- it kind of takes the human element out of it and puts the shoes where they are supposed to be. just one of them any things i learned from my grandpa (professional small town mechanic for over 40 years) when i was growing up.
back before i redid my Nova, i had to "self adjust" the 4 wheel drum brakes every couple of weeks or so. the pedal would start to get soft and/or the car would start to pull to one side when applying the brakes. a couple of quick stops in reverse, and the pedal came right back up.
this also applies to cars with discs on the front and drums on the rear- after a while, the pedal starts to go soft due to the rear brakes having slack in them. just self adjusting them every week or so- or, preferably, every time you back up (you don't need to go 15mph every time- just come to a complete stop every time you back up). this keeps everything where it should be, and keeps your ring and pinion gears happy because you aren't doing reverse drops every time you back up.

 

Put the front end on jacks today. When I let the wheels spin freely, they dragged slightly then no resistance, then dragged, and so on.
That means the drums are not completely circular, right?

As for taking the drums off, they came right off without any problems. Brake shoes look OK. Is the rear facing shoe supposed to be thicker than the front facing one?
Drums look OK, with some rust? and stripes/grooves. No leaks what so ever.

I'll take them to a machine shop and let them make them nice, round, rust and groove free again.

Then we'll see.

 

Didn't see it! If your efforts don't solve the problem, the same sort of deviation happened to my disc car about 20 years ago. One of the rubber hoses was failing. The inside was delaminated and caused the fluid to be restricted when pressure was applied. The car did all sorts of crazy stuff. I don't know why a drum car would be different.

 

I'm reviving this tread. I've had the drums done by a machine shop, so they are nice and round.
The car is now within limits (passed the inspection), but it still pulls to the left. I've adjusted the brakes several times, but no improvment.
The brake shoes look OK, and I can't see any leaks from the brake cylinders. Everything is nice and dry behind the drums. The main reservoir is full.
I got my son to push the pedal, and the brake shoes on the right side do move.
The pedal is quite nice and firm.
I've not bled the system, but both front brakes share the same lines? That means both sides should be affected if air was the problem? Or could air be trapped in such a way that only one side would be affected?

Thanks for the tip on the hoses!

Is there any way I can measure the brake pressure in the line?

 

Replace the rubber hoses if you have not already.
I had an old one plugged up once.

 

Each front line is separate from the master cylinder. The back is a singler line from the front to a tee above the rear. Bleed them all starting with the farthest from the master. RR, LR, RF, LF. May take several rounds.