1957 brake booster won't release brakes

[Jon S]

Have you checked the brake push rod length?  It's an adjustable rod attached to the brake pedal with a nut and locking nut for adjustment.  If it's too long, your power brakes WILL lock up and not release for some time.  The length of the push rod must be adjusted to 4 7/8" +/- 1/8".  This is the distance from the pedal reinforcement to the retainer seal and a picture can be found on Page 8-6 of the 1957 Shop Manual.  I will bet yours is in excess of 4 7/8"!  A simple fix!  Let me know what you find.

Jon

[David King (kz78hy)]

The dimension in the manual was wrong and Cadillac Serviceman bulletin was noted that had the correct dimension.  I will have to look it up, but the most important thing is to make sure the pedal comes all the way back up so the master cylinder gets a recharge.

The correct dimension is 4 7/8" but you measure from the forward in car (back side of the pedal frame) instead of the graphic which shows the cross bar which is more rearward in car.  May 1957 pp 46 Serviceman is the note.

David

[cadman49]

where do you guys get that neets foot oil and where exactly where do you put it in??? r king--57 de ville

[Quentin Hall]

Most saddlery stores here in Oz have neets foot oil. However any good quality leather dressing should condition the leather if it is dried out.
Interesting about the pedal measurement....though that would also affect the brakes even if the booster was not connected...so unlikely the problem I'm experiencing.

[Jon S]

The dimension in the manual was wrong and Cadillac Serviceman bulletin was noted that had the correct dimension.  I will have to look it up, but the most important thing is to make sure the pedal comes all the way back up so the master cylinder gets a recharge.

The correct dimension is 4 7/8" but you measure from the forward in car (back side of the pedal frame) instead of the graphic which shows the cross bar which is more rearward in car.  May 1957 pp 46 Serviceman is the note.

David

David -

Could you post a picture of the Serviceman note please.

Jon

[Jon S]

David -

Could you post a picture of the Serviceman note please.

Jon

Bump

[Roger Zimmermann]

With a little help from abroad!

[Quentin Hall]

G'day Roger, Thanks Mate. When you say "With a little help from abroad!" . . . are you meaning that you got a woman to do it for you ??
     Sorry . . . I couldn't resist. Q

[Roger Zimmermann]

Sorry, cannot understand your remark...makes no sense to me.

[Jon S]

With a little help from abroad!

George -

Fantastic!  Thank you very much!  I just checked mine and it is on the mark.

Jon

[David King (kz78hy)]

Thanks Roger,  I have been busy and not checking the forum as much.

David

[Roger Zimmermann]

Thanks Roger,  I have been busy and not checking the forum as much.

No problem David, if I can supply some info I'll do it...

[Renato]

Picture saved, thank you!