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Author Topic: 1957 brakes power assist ?  (Read 115 times)

Offline gary griffin

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  • garygriffin@Q.com
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  • Name: Gary Griffin
1957 brakes power assist ?
« on: December 07, 2017, 06:38:01 PM »
It seems like my 1957 has deficient brakes. There is no vacuum reservoir and I have since learned that they had a one year only master cylinder.  I was driving it without an air cleaner and the brakes were very poor although I had the master cylinder and power assist rebuilt by a specialist.  Will reinstalling the air filter create more vacuum and make the brakes safe? Other 1957 owners please let me know if you have specific knowledge about this?
« Last Edit: December 07, 2017, 06:45:59 PM by gary griffin »
Gary Griffin

1940 LaSalle 5029 4 door convertible sedan
1942 Cadillac 6719 restoration almost complete?
1942 Cadillac 6719 (parts car) (Gone)
1957 Cadillac 60-special (Needs a little TLC)

Offline Dave Shepherd

  • Posts: 1933
Re: 1957 brakes power assist ?
« Reply #1 on: December 07, 2017, 08:36:16 PM »
No reason the air cleaner should have any effect on vacuum supply. That system certainly can be problematic, I've had quite a bit of experience with it. Whats wrong? No assist, low pedal?

Offline gary griffin

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  • garygriffin@Q.com
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      CLC Member #26430
  • Name: Gary Griffin
Re: 1957 brakes power assist ?
« Reply #2 on: December 08, 2017, 10:32:19 AM »
It takes a hard push on the pedal to get any brake at all.  About as much as if there were no power assist. I was assuming that the power assist was using manifold vacuum provide the assist as power source and the air cleaner may cause it to have greater vacuum by restricting air flow to some degree?  I have never seen a power assist without a vacuum reservoir though ??
« Last Edit: December 08, 2017, 11:38:30 AM by gary griffin »
Gary Griffin

1940 LaSalle 5029 4 door convertible sedan
1942 Cadillac 6719 restoration almost complete?
1942 Cadillac 6719 (parts car) (Gone)
1957 Cadillac 60-special (Needs a little TLC)

Offline Dave Shepherd

  • Posts: 1933
Re: 1957 brakes power assist ?
« Reply #3 on: December 08, 2017, 05:03:31 PM »
The system does not use a reservoir, now there is a check valve in the vacuum feed off the intake. Makes sure that is ok, you should have plenty of vacuum at the hose connected to the booster. If all that checks and you have no power assist, most like the Hydro Vac is the problem.

Offline gary griffin

  • Posts: 2115
  • garygriffin@Q.com
    • CLC Member
      CLC Member #26430
  • Name: Gary Griffin
Re: 1957 brakes power assist ?
« Reply #4 on: December 08, 2017, 05:27:39 PM »
Thanks Dave,   I drove it to upholsterers and had no real boost.  I will double check everything when I bring it home. I had Hydra Vac rebuilt a couple of yeas ago but it sat out the the one year guarantee. That is the problem with these long projects.
Gary Griffin

1940 LaSalle 5029 4 door convertible sedan
1942 Cadillac 6719 restoration almost complete?
1942 Cadillac 6719 (parts car) (Gone)
1957 Cadillac 60-special (Needs a little TLC)