Help! Can't stop....
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Senior User
Joined: Sep 2004
Posts: 457
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Help! Can't stop....
I don't know if this is the proper forum for this, but I think is has something to do with the vacuum.
OK, first off, here’s a little background on where I live. The hill I live on climbs approximately 1000’ in a matter of about 3 miles. As you can imagine, it is fairly steep. My problem is that, when heading down the hill, by time I get to the bottom of the hill there is very minimal brake there. My ttruck is a 75 hi-bpy with <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com
ffice:smarttags" /><st1:time Hour="16" Minute="11">4:11s</st1:time> and a C6 auto. I almost always drop er in 2<SUP>nd</SUP> heading down the hill to use as a jake brake. However, I’ve come to realize, that if I step on the gas just a little bit, then the brakes work better. Is it because of lack of vacuum? Is it just not building enough vacuum while headed down the hill with out touching the gas pedal? I would assume the darn thing would be. Any thoughts/suggestions would be greatly appreciated.
Thanks!
Mike
OK, first off, here’s a little background on where I live. The hill I live on climbs approximately 1000’ in a matter of about 3 miles. As you can imagine, it is fairly steep. My problem is that, when heading down the hill, by time I get to the bottom of the hill there is very minimal brake there. My ttruck is a 75 hi-bpy with <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com
ffice:smarttags" /><st1:time Hour="16" Minute="11">4:11s</st1:time> and a C6 auto. I almost always drop er in 2<SUP>nd</SUP> heading down the hill to use as a jake brake. However, I’ve come to realize, that if I step on the gas just a little bit, then the brakes work better. Is it because of lack of vacuum? Is it just not building enough vacuum while headed down the hill with out touching the gas pedal? I would assume the darn thing would be. Any thoughts/suggestions would be greatly appreciated.Thanks!
Mike
Elder User
Joined: Nov 2002
Posts: 620
Likes: 8
From: USA
Your idea sounds reasonable. Have you checked for vacuum leaks? Have you put a vacuum gauge on it to see if you really do have poor vacuum at idle?
Not sure if a bad brake booster has these symptoms or not.
Jordan
Not sure if a bad brake booster has these symptoms or not.
Jordan
Fleet Owner
Joined: Jan 2004
Posts: 26,007
Likes: 575
From: Brentwood,CA
i would check the vacuum and idle speed you should have about 20 vacuum for everything to work right unless its your cam in which case find a chevy electric vacuum pump and you will always have plenty of vacuum
Post Fiend
Joined: Jun 2002
Posts: 13,873
Likes: 3
From: Atlanta GA
Check the check valve at the booster, a new one is cheap, and they are only made of plastic. Check the engine with a vacuum gauge at idle, you might have to adjust your carb or rebuild it if its leaking. If you have a bouncing guage, you know something is wrong.
Postmaster
Joined: Jul 2003
Posts: 3,934
Likes: 0
From: iowa
The range for the manifold test is 15-22 inches. For a stock cam you would want 18-22. There should be no need to rev the engine. I would check, no replace the rubber hose to the booster and the plastic valve that i know very little about heck maybe the rubber grommet is cracked where the valve is.
