Brake booster vacume pump.

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tekslk

tekslk

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Anybody use one on there power brakes? Tell me about it where to get one hook it up or fab one. I just changed over to power brakes and at idle Im a little low on vacume, I did install a canister which helped but not 100 percent yet, I may end up living with it.
 
How low is your vacuum? I believe your cam is not overly radical? I ran PB's down to 9"s of idle vacuum before on limited use cars. With deceleration, it would build enough vac to stop decently. The only issue I had was with stop and go traffic, or repeated pumping of the pedal. I will admit that full, daily driver type performance was lacking, but with the price of electric vac pumps, I just learned to live with it.
 
The street driving is great even at stop signs no problem, where the trouble comes is if I turn around in the driveway which is slightly up hill im using them alot at a idle and sometimes get the hard pedal like no power brakes left. I can live with it over the 300 dollar fix, Im more concerned if son or wife would pull it out of garage and say oh ****. If they only tap the pedal once or twice its ok but anymore than that it get hairy.
 
tekslk said:
The street driving is great even at stop signs no problem, where the trouble comes is if I turn around in the driveway which is slightly up hill im using them alot at a idle and sometimes get the hard pedal like no power brakes left. I can live with it over the 300 dollar fix, Im more concerned if son or wife would pull it out of garage and say oh ****. If they only tap the pedal once or twice its ok but anymore than that it get hairy.
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I understand Tom, it's kind of a learning curve operating a performance car. The only advise I could give with the current setup would be to teach them to rev the engine, in neutral, a few times while moving it to build a little vacuum. The few PB cars i personally owned had a check valve at the booster. It helped to hold some vac as the engine came back to idle.
 
I have a check valve in the booster and the canister, maybe after a drive tomorrow Ill get used to it. Its not that bad just not like these newer cars. Probably after three or four drives in it I will be used to it. It really drives nice on open road.
 
Recent VW diesel cars have an electric vacuum pump for the brake booster. You can sometimes find on ebay <$100.
 
Any diagnosing been done ? Got a vacuum gauge ?
 
Vacume is about 19 when driving,12 at idle in neutral, in gear stopped about 4-5 thats why Im thinking a extra pump. I drove it about 50 miles today and it works fine on the road and at stop signs, just a little iffy in the drive way turning it around and stuff when you hit the brakes 3-4 times it uses all the vacume.
 
That's a huge drop. I know you are running pretty stout initial timing, but is there a chance that idling out of gear that your rpm is high enough to be into the curve already? Then once it drops a few hundred in gear, that it's retarding the timing some? Hope this makes sense...:D.
 
It sounds to me like your advance curve is starting a little too early. One way to check, with a assistant, would be to throw a light on it out of gear, then check it again in gear. If it drops, then you may have to add a stiffer spring to allow the mechanical advance to start after the 1200 idle speed. I've had several cars that vacuumed in the 10/12 range and none dropped more the 2" in gear. Lets see if some others have a thought or two? That's just the first thing that came to mind.
 
Ok so maybe there isn't a small leak as I suspected. The cam mfgrs will note the vacuum versus power brake problem in their description. Hydra boost is old school I suppose.
Good luck with it.
 
Mid 2000's chevy trucks,tahoes ect. also had a vacuum assist pump. Just got done Friday bench testing the one my dad picked up at the j/y for install on his 58. Works well that way, we shall see how it does in real life sometime this week.
 
Well I ended up going cheap and put 2 brake canisters on for now but that holds enought to keep the brakes working, till spring I will probably buy the 300 dollar pump.
 
Well I bit the big one and bought the comp vacume pump $300 bucks but now that its hooked up Ihave all the brakes I need when ever I want them. You can here the elect motor run if you pump brakes down. With the engine running you dont even here it run. Now I have 2 Jegs chrome vacume canisters if anyone can use them I have all hardware. They were $50 shipped I will sell for 30 each and I pay the ride in the usa. Pm me if insterested. They are brand new condition.
 
I have followed your thread and am wondering if your pedal was one that went soft and fell or went hard but stayed off the close floor? I have a stout cam and am wondering about the electric fix?? Where did you buy yours?
easy to hook up? I have line lock from hurst which works great just a un predictably pedal when driving . already replaced master .Would like power brakes for easy pedal.
RBEE
 
Bought the comp air pump from summit, easy to install. You can here it when you turn the switch on but fairly quite when driving. Im more than satisfied. One thing I discovered was I had to put a clamp on the hose going to the brake booster, it wasnt sealing tight. You may want to look into that. I thought mine was but it actually wasnt.
 
Almost any diesel thy doesn't have hydro-boost will have a pump.. old VW diesels had the pump where the distributor was as that motor was just an ultra high compression gas motor with diesel injectors instead of spark plugs. Hydro boost may be cheaper than 300 at a boneyard if you don't mind the plumbing.
 
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