abrasv

Just replaced the power drum brakes on my 69 Cutlass. Front cylinders were sticking and shoes were about half gone. Replaced them at same time. Rear brakes are in very good shape so adjusted them a bit to where the wheel was just starting to tighten up. Bled the fronts and got the air out and good stream of fluid. Then adjusted them the same as the backs (just where they started to tighten up. All this time I made sure there was fluid in both reservoirs.
Took for a test drive and pedal still goes almost to the floor. What did I miss here?

oldcutlass

Sounds like you still have air in the lines.

abrasv

Just backed it in the shop and after I turned it off the pedal was where it should be. Turned it back on and it went almost to the floor.

oldcutlass

With the engine running if you can pump the brake pedal and it firms up you probably have air in the system.

abrasv

Tried that but it won't pump up. Stops straight when braking but really need a little more pedal!

oldcutlass

Did you change the master cylinder?

abrasv

Did not change the master cylinder.

oldcutlass

Since you did not mess with the booster or MC there are only a few of things that cause your issue. 1 is the adjustment and by the description you gave they should be adjusted correctly, 2 is air in the system, and 3 is an internal bypassing MC. If the brakes worked fine before then they should work now, still going with air in the system.

abrasv

Right now the brakes work as they should in stopping me. I ws just wondering about the pedal going so far down before they do engage.
I think I will look at bleeding all 4 again. The front drum brake bleed screws are very hard to get a wrench into and I feel I may be allowing air back into the line before I get it tighten all the way.

I appreciate your help, Eric.

Fun71

You say you replaced the front cylinders. Have you checked them so see if they are leaking? New does not always mean good, unfortunately.

edit: just saw your last post. That sounds as if may be the issue.

abrasv

UPDATE:
Put a new master cylinder on it and pressure bled the whole system. Brakes work good and pedal is now where it should be.I appreciate all the responses as that helped point me in the right direction.