72Cutlass_442

Hello all,
I have a 1972 cutlass with all drum brakes. I don't drive it very often as my roof is rusting through. I was going drive it to a body shop to see if they could fix the roof issues but when I used the brakes, the pedal went to the floor and the red brake light came on and I was barely able to stop. So this weekend I first bled the brakes. It didn't help so I trouble shot the brake shoes and the wheel cylinders. The pads were not worn and the calipers were not leaking. I checked the lines for any damage and there was none. So I checked the booster and it holds pressure and responds to the vacuum of the engine. So I replaced the master cylinder and bled the brakes again. It now has better stopping power but still feels weak. I tried locking up the brakes but I couldn't. Is there any thing I'm missing. I also braked in reverse and pressed the parking brake in case they need to be adjusted. Do I need to check something else? Or are my brakes just not very good?

oldcutlass

You may still have some air in the lines. Are there any signs of leaks? In addition your brakes may need an adjustment. Also if the car has been sitting for a while there will be some rust build up on the drums that will hinder the brakes from gripping properly until that is worn off.

redoldsman

If you have all drum brakes then you don't have any pads and calipers. You have shoes and wheel cylinders. Be sure to bench bleed the master cylinder in a vise with it level. That is the only way you will ever get all the air out of the system.

72Cutlass_442

Sorry for the incorrect terminology. I bench bled the master cylinder before I put it on the car so there shouldn't be any air in it...as far as I know. And I've bled the brakes three times since I put the master cylinder on. How do I adjust the brakes?

72Cutlass_442

I can't find any signs of leaks anywhere. I've checked the hoses and lines as well as the wheel cylinders but there are no signs of brake fluid. How do you adjust the brakes? Maybe the rust is keeping them from locking up or responding properly.

oldcutlass

I set them with a brake spoon from the inside of the backing plate. There are rubber plugs back there that you remove or a knockout if no one has ever removed it right behind the barrel adjusters. You may need a small flat screwdriver to push the adjusting arm away if you over tighten the shoes. I turn them in until they are just barely touching the drum.

72Cutlass_442

Ok I'll try that. Thanks!

rustyroger

I adjust drum brakes until the drums are tight to turn, then back them off until they turn freely again. This help ensure the shoes are correctly located.

Roger.