Brake booster
Thread Starter
Instructor
Joined: Jan 2004
Posts: 242
Likes: 4
From: deland fl
Brake booster
HI guys..
I bought another '75 convertible a few months ago and when driving it home I had to stand on the brake pedal to bring it to a stop. I guess that would indicate the booster is not working. I have the body off it and the motor out and want to refinish the engine compartment. Before I bother to make the booster "pretty", is there a way to test it under the current conditions ? If it is in fact "bad", can it be rebuilt ? Or...should I just go to Oreilly's and buy a new or rebuilt one ? I have already just about blown my budget so cost will be a factor.
TIA
Ya'll Enjoy !
Larry
I bought another '75 convertible a few months ago and when driving it home I had to stand on the brake pedal to bring it to a stop. I guess that would indicate the booster is not working. I have the body off it and the motor out and want to refinish the engine compartment. Before I bother to make the booster "pretty", is there a way to test it under the current conditions ? If it is in fact "bad", can it be rebuilt ? Or...should I just go to Oreilly's and buy a new or rebuilt one ? I have already just about blown my budget so cost will be a factor.
TIA
Ya'll Enjoy !
Larry
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
The factory boosters have a typical ~4" of brake pedal travel to get any secure braking, it is typical of all GM cars over the decades.....and especially noticeable on the C3 vettes.....nature of the beast...there are guys who are used to it, and guys like me that hated that feeling,.....
the ONLY way to ditch it good and proper is to put in a Hydro Boost brake setup that runs off the power steering pump, THEN the pedal has about 2" of travel and the brakes are hard as a brick.....also ditch that silly f/r brass block with the switch on it, plumb directly to the m/cyl......
and obviously the calipers need be checked out, and probably O ring pistons installed....
further questions, feel free to PM me....as I maybe not see this thread.....
the ONLY way to ditch it good and proper is to put in a Hydro Boost brake setup that runs off the power steering pump, THEN the pedal has about 2" of travel and the brakes are hard as a brick.....also ditch that silly f/r brass block with the switch on it, plumb directly to the m/cyl......
and obviously the calipers need be checked out, and probably O ring pistons installed....
further questions, feel free to PM me....as I maybe not see this thread.....
Team Owner
Joined: Jun 2000
Posts: 38,923
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From: Southbound
Cruise-In II Veteran
Not necessarily, but it does indicate the brake system needs attention. Stranger things have happened, but stock boosters seldom fail.
Why not wait until you get the car back together, then determine the problem.
Why not wait until you get the car back together, then determine the problem.
Drifting
Joined: Sep 2010
Posts: 1,412
Likes: 50
From: Laguna Niguel California
I don't entirely agree with just getting another generic booster. I had a rebuilt one installed recently that had an internal flaw. As soon as you would start the car the booster would start to gradually pull the pedal down and apply the brakes. You could pull it back up but as long as the car was running the pedal would creep down. Do yourself a favor and buy the best quality available.
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
I recently installed a replacement booster on my '79 mainly because I didn't like the look of the original. The replacement works, but there is something about the feel of it I don't like. Its not the same as the original. The pedal just feels a little more mushy. The brakes work, but its not right. I had the stock booster on my '66 rebuilt and replated a few years ago and its perfect. I'm thinking about having the stocker from my '79 rebuilt also. Just sharing my experience. Take it for what its worth.
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
http://www.boosterdeweyexchange.com/
Booster Dewey..They did my '66 booster. Very happy with the result.
Should cost you about $175. Do it quick before they figure out what a bargain that is!
Booster Dewey..They did my '66 booster. Very happy with the result.
Should cost you about $175. Do it quick before they figure out what a bargain that is!
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Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
Are you absolutely sure that the booster was getting good vacuum signal and that the check-valve at the booster input was functioning properly? It would be disappointing to buy a new or rebuilt booster, only to find out that vacuum wasn't getting to it..... 
Thread Starter
Instructor
Joined: Jan 2004
Posts: 242
Likes: 4
From: deland fl
Ya'll Enjoy !
Larry
Race Director
Joined: Feb 2006
Posts: 12,239
Likes: 19
From: Chino CA
And as mentioned before, original boosters seldom go bad.
Race Director
Joined: Apr 2009
Posts: 19,294
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From: Charlotte NC
For what it is worth.
If your oil dipstick is on the left side...the booster is different than that of the engine with the dipstick on the right side. They both will bolt to the firewall...but the shape of the outer half of the booster is different...along with how the outer half is stamped for the master cylinder is also different.... and if you use a later year model...you will have a fit in getting to and correctly using your oil dipstick.
I have run into the vacuum check valve not working correctly and causing a booster to seem to be bad.
Also I go to a "Piretek" shop near my shop and get the thick walled hose like GM used on many year models. I prefer it instead of regular 3/8" fuel hose....due to the correct tension clamps work on the thicker walled hose versus the fuel hose.
DUB
If your oil dipstick is on the left side...the booster is different than that of the engine with the dipstick on the right side. They both will bolt to the firewall...but the shape of the outer half of the booster is different...along with how the outer half is stamped for the master cylinder is also different.... and if you use a later year model...you will have a fit in getting to and correctly using your oil dipstick.
I have run into the vacuum check valve not working correctly and causing a booster to seem to be bad.
Also I go to a "Piretek" shop near my shop and get the thick walled hose like GM used on many year models. I prefer it instead of regular 3/8" fuel hose....due to the correct tension clamps work on the thicker walled hose versus the fuel hose.
DUB
Thread Starter
Instructor
Joined: Jan 2004
Posts: 242
Likes: 4
From: deland fl
Hi Guys...
Don't want you to think I'm ignoring your help and suggestions but I've got family coming down from the frozen north tomorrow. When I'm free again, I'll let you know whats goin' on with my problem. About a week maybe ...? You guys are great.
Ya'll Enjoy !
Larry
Don't want you to think I'm ignoring your help and suggestions but I've got family coming down from the frozen north tomorrow. When I'm free again, I'll let you know whats goin' on with my problem. About a week maybe ...? You guys are great.
Ya'll Enjoy !
Larry
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
I have seen the hose suck shut due to it being the wrong type of hose.
DUB