Just did complete brake job on 63 230sl; brake cylinders replaced, master cylinder, etc. I bled the brakes, and thought all was well, but each time brakes are applied, the brake pedal doesn't return to original position. Note: When bleeding, I accidently pushed the brake pedal all the way to the floor. Am wondering if this could have damaged the o-rings in the master cylinder, or damaged the brake booster (which I did not replace).
If I push on the mechanism (pushrod) where it comes thru the firewall and goes into the booster, the pedal returns to full up position, only to have the same thing happen again when the brakes are next applied.
Help please!
sdeminco@aol.com

Try it with the emergency brake on. If it makes a difference try adjusting the rear shoes. If it doesn't matter then I would retry the bleeding again.

230Sl brakes
 

You didn't mention whether the car still rolls easily after releasing the brake or whether you replaced the brake hoses. After that many years the hoses can occlude.

Peter

Re: 230Sl brakes
 

Peter,
Until I replaced the front brake cylinders, the brakes were hanging up (corrosion of the pistons/sleeves due to long term storage moisture I suspect); took about 3 hours before they "relaxed" to the point where the car would roll.
But that portion of the problem no longer exists.
Steve

If you would like to test your flex hose for constrictions, [ which is common on vintage systems],
I use this simple test.
Raise each wheel to be tested off ground. Have someone press pedal down firmly for a moment. Then, after releasing pedal, try to turn the wheel by hand. If it does not release, quickly open the bleeder. If tire now turns, hose
is constricting.
The bad hose acts like a one way valve because the pedal pressure is so much more than the return pressure.[ hardly none].
So, essentually, the breaks work, but don't release.

I might as well also add:
With same procedure, If opening the bleeder does
NOT release the brakes, a frozen caliper is suspect.

Peter,
I don't think you could have damaged anything by pressing the pedal too far. It sounds like the problem is in the pivot mechanism between the pedal and the booster(that aluminum housing under the hood). It may be binding due to corrosion. If the booster were damaged it would leak causing the car to run oddly when the pedal was depressed. When the brakes stick, have you tried lifting the pedal up with your foot? If the pedal just flops back down when lifted from inside the car...that too would make me look closely at the pivot assembly.
Regards,
Randy D.

Randy D. has a good point on checking the linkage pivot assembly behind the booster.
An added adjustment that you may want to confirm is the
brake booster rod to the pivot assembly he has mentioned.
There is a connecting bolt/nut there that is eccentric and it had an Index mark on it. It is at it's maximum eccentricity when pointing Rearward. This adjustment assures
that there is free play between the linkage/pedal and the master/booster. You can fell this play by pulling the rod toward the front of the car. If there is no free play, get some by this adjustment or it is possible for the brakes to have residual pressure from the master.