Power Brake Booster - Leaking?

[Patrick H.]

Hello All,

While trying to fine tune Dad's 72, now that I have it running, I have had a tough time getting it to idle well and at a reasonable speed. It would stay at 1500 rpm, but would die easily below 1000. It acted as if it had a vacuum leak, but even if I disconnected and blocked the vacuum lines to the intake, it ran the same.

The car has 350/200 auto with Power brakes, PS, AC.

Tonight, while putting the car on the trailer to bring it away for final paint touch-up, I noticed that when I pushed on the brakes, the idle came down nicely and smooted out, as if the vacuum leak disappeared. In addition, the brake pedal is soft for the first 2/3, very hard for the last 1/3. Am I to assume that this is showing me that the power brake booster is leaking/broken, and needs to be replaced? And if so, what is my best source for a booster? New or rebuilt? AutoZone? Delco? Booster Dewey? The car is a very nice driver, and I am not as concerned with 110% originality, but with functionality.

Thanks,

Patrick Hulst

[Dave - NCRS#24235]

Re: Power Brake Booster - Leaking?

Disconnect the vacuum line to the power brake and try it. If it's the brake, and it acts like mine did when it died, be sure you mark the back of the unit when you send it - and note the date code on the ear - best of all, photograph the date and mark - before you ship it. Otherwise you may not ever see the correct unit again. I had mine done by Long Island Corvette. It turned out that two 66 power brake units came back to them from the rebuilder on the same day, and they screwed up and switched them. I got an ugly looking unit (had been wire brushed by the owner) back and it took several phone calls before they gave me the name of the person who got mine. Luckily that person agreed to ship mine to me while I shiped to him. Mine looked great (same rebuilder) and has worked fine for five years. - Dave