How much??
Thread Starter
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
How much??
vacuum is needed to operate the power brakes on a car? Dad's chevelle has 10" vac at idle, and his breaks are a BEAR to operate at slow speeds. We got a vacuum canister and I was playing around with it yesterday in his driveway. We did not have enough hose to mount it, but I did hook it up and when he tapped his gas a little the guage on the canister, went up to ~22" up from the previous mentioned 10".
Do you brake gurus think the problem is his 10" or something else. We just replaced on Thursday ALL the fluid in his system with new stuff, and that helped a little, but the brakes are still less than adequate.
Today he's going to mount the vac canister, but I was just curious as to what exactly is needed. Furthermore, does anyone here run a canister on their vette? I was thinking of plumbing his in, to see if it makes a difference. My car at idle is around 15", my brakes are MUCH MUCH better than his.
PS: He has upgraded wildwood disks on the front.
Thoughts? :cheers:
Do you brake gurus think the problem is his 10" or something else. We just replaced on Thursday ALL the fluid in his system with new stuff, and that helped a little, but the brakes are still less than adequate.
Today he's going to mount the vac canister, but I was just curious as to what exactly is needed. Furthermore, does anyone here run a canister on their vette? I was thinking of plumbing his in, to see if it makes a difference. My car at idle is around 15", my brakes are MUCH MUCH better than his.
PS: He has upgraded wildwood disks on the front.
Thoughts? :cheers:
Le Mans Master
Joined: Feb 1999
Posts: 6,172
Likes: 11
From: somers, ny
Re: How much?? (ski_dwn_it)
10 is kinda low and could be the cause of his braking problems at idle.
SLOW DOWN those pictures i your sig.......they make me dizzy trying to look at them :crazy:
SLOW DOWN those pictures i your sig.......they make me dizzy trying to look at them :crazy:
Burning Brakes
Joined: Apr 2002
Posts: 1,126
Likes: 0
From: Cleveland OH
Re: How much?? (ski_dwn_it)
Furthermore, does anyone here run a canister on their vette? I was thinking of plumbing his in, to see if it makes a difference. My car at idle is around 15", my brakes are MUCH MUCH better than his.
I had the Comp Cams vacuum canister on my car. My vacuum was 15" at idle as well and I found the canister to make a huge difference in pedal effort. I never checked the vacuum at the canister following its install, but it was a noticeable difference over not having the canister. I didn't get to run with it that long before the bearing spun, and I'm not sure of MORE is going to put the canister back on with the 396.
Ron
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: How much?? (ski_dwn_it)
It could simply be the amount of vacuume available. But, did he upgrade the master cylinder when he installed the discs? Besides not using a residual pressure valve, dics brakes generally require higher line pressures to opperate properly. If the m/c was changed, what does Wildwood say about lackluster braking for his application? Do they offer an alternate m/c? If the reservoir makes him happy, go with it. I would still quiry Wildwood. Good luck, and...
RACE ON!!!
PS. Disc brakes have NO servo action. The old drum brakes probably would do a better job of holding the car at the line while bringing the R's up against the converter. Trans brake time?
RACE ON!!!
PS. Disc brakes have NO servo action. The old drum brakes probably would do a better job of holding the car at the line while bringing the R's up against the converter. Trans brake time?
