BRAKE PEDAL NOT RETURN-1957 PONTIAC POWER BRAKE

[Marty Roth]

Not mine-

 

my friend's '57 Pontiac Super Chief power brake pedal must be pulled up manually and then the car drives as it should, but each time he applies the brake the pedal will stay down until pulled back up. He has installed a "temporary" return spring above the pedal assembly arm and with this "fix" the car seems to function normally with the pedal returning to the full-up position. This condition occurred following lunch on the Mississippi Gulf Coast in Gulfport, MS at the midpoint of a 160 mile drive. 

 

What is causing this condition?

How can I help him solve it?

Any suggestions appreciated - thank you

Edited December 17, 2017 by Marty Roth (see edit history)

[Spinneyhill]

Original spring broken?

 

Is the pivot clogged with dirt etc. after the application of oil?

[Marty Roth]

26 minutes ago, Spinneyhill said:

Original spring broken? We Did not notice an original spring, where would it have been located or attached?

 

Is the pivot clogged with dirt etc. after the application of oil?  - Does not appear to be the case 

 

thank you

Edited December 17, 2017 by Marty Roth (see edit history)

[61polara]

If this is the same style power brake booster as a '57 Buick, look for a housing cover on the top of the booster with a screw in the middle of the top of it.  Remove the cover and drip a few drops of transmission fluid in the opening.  Pump the brakes and see it they start to return.  This is covered in the Buick shop manual, so check the Pontiac manual as well.

 

I was on the road to an AACA Meet and had to drip fluid from the transmission dip stick.  I don't remember how many drops, but with pumping the brakes, it returned to normal quickly and we were back on the road.  Thankfully we had a shop manual in the car to research.

Edited December 20, 2017 by 61polara
Corrected fluid from motor oil to trans fluid. (see edit history)

[dl456]

Marty,

I use 10 weight or transmission fluid. There will be a screw or small pipe plug.

There should be check valve in the vacuum line. Check this for proper operation.

If the piston is dry, It may take multiple cycles of the pedal to correct.

Dennis

[Marty Roth]

Thank you all - I will continue to pass along your responses to Charles in the hope of getting his car back on the road

[m-mman]

My 1959 Lincoln came to me with a spring hooked under the dash to pull the pedal up. 

I rebuilt the booster and it would not return. 

I had the booster professionally rebuilt and it STILL would not return. 

 

Eventually I pulled apart the entire pedal linkage. Turns out they were dry and 'stuck'. I polished and lubricated the pins  (There are two pivot pins on 59 Lincolns and they have nylon bushings) and without being attached, the pedal system (finally) swung freely and now returns properly with the booster. 

People readily repair the booster, but dont think about pulling apart all the linkage for cleaning and lubrication. 

[Marty Roth]

Thanks m-mman, I forwarded your post to the owner .

He assures that he'll explopre, and appreciates the advice.