Electric Vacuum

[geostang351]

I have power disc brakes from a Granada swap and a radical cam that doesn't produce enough vacuum at idle. As I slow down from say 50 mph, I stop very quickly. However, the last 10 mph are sometimes scary (feels like I'm going push the brake pedal support through the fire wall). I've been looking through the summit catalog but cannont find the electrical vacuum canisters for this problem. Under what catagory would this be listed?

Thanks

 

[GoinBroke]

I do not have a catalog handy but they are listed online under vaccum pump and canister.

 

[thehueypilot]

Try "electric vacuum pump" and another cheaper different option is a vacuum canister. The vacuum canister has a check valve in it to capture the highest vacuum your engine produces and stores it until you need it. I run one on my race car which idles at 5 in/mg but at the end of a run it produces about 18 in/mg which gives me a very easy pedal.

 

[Max Power]

I thought storing vacuum was a good portion of the boosters job.

I run 10' at idle, and I have very little trouble stopping. What are your vacuum readings Geostang?

 

[grego37]

If you have power steering, you may want to consider a hydroboost unit, allot of people swear by them.

 

[geostang351]

I thought storing vacuum was a good portion of the boosters job.

I run 10' at idle, and I have very little trouble stopping. What are your vacuum readings Geostang?

I don't have a vacuum gauge to determine vacuum.

 

[C0V3R]

I used a vaccuum pump on my engine when the valves were on their way out. Worked quite nicely to improve the pedal feel. Had to put a bit of effort into muffling it though.

 

[geostang351]

I see that this is about a $200 difference between the cannister and the electric pump. CAn I get away with using the cannister and not the pump?

 

[Max Power]

First thing I would do is get a $10 vacuum guage and determine if you really need to spend all that money.

When you are driving down the road, and you lift the throttle, your vacuum goes to the highest reading. I idle at 10-12", but deceleration on the road is around 20", which is more than enough for power brakes. If you apply the brakes while at 20" of vacuum, which is most the time, it will hold that vacuum. As a matter of fact, power boosters are designed to give one fully assisted stop should your car stall, which is zero vacuum.

I would make sure you really need to spend this money before diving in.

 

[geostang351]

First thing I would do is get a $10 vacuum guage and determine if you really need to spend all that money.

When you are driving down the road, and you lift the throttle, your vacuum goes to the highest reading. I idle at 10-12", but deceleration on the road is around 20", which is more than enough for power brakes. If you apply the brakes while at 20" of vacuum, which is most the time, it will hold that vacuum. As a matter of fact, power boosters are designed to give one fully assisted stop should your car stall, which is zero vacuum.

I would make sure you really need to spend this money before diving in.

Well like first posted, as I complete the last 10 mph, you're saying I should have enough vacuum. If I do have enough, then what other problem may I be facing with my brakes? Any ideas?

 

[Max Power]

If you are stopping OK from 50mph, but are having problems with the last ten MPH, that sounds really odd to me. The booster doesn't lose assist if working properly during one stop. I am not sure what to tell you, other than I think there may be some problem in the braking system, like a marginal booster, or something like that.

It just doesn't sound right. although I have never done the Granada swap, so I am hoping someone who has can weigh in.

 

[geostang351]

Oh, after a ride last night, it appears It get tough the last 10 mph because my pedal is bottomed out. Not too safe. Guess I have to bleed the brakes as I may have air trapped in the line.

 

[Max Power]

I figured it was something like that....