Help me with vacuum pump for brakes !

[6spdg37s]

So I installed the CVR 555 vacuum pump , the instructions give 2 options for install one being from manifold to the exhaust port on the pump and then the vacuum port on the pump to the booster.

2nd is vacuum port on manifold to check valve to T fitting then the bottom of the T fitting goes to the vacuum port and the ehxaust stays open and the other side of the T goes to the brake booster

I have it hooked up the 2nd way and the pedal feels like it has vacuum but as soon as u go to move the car it goes back to rock hard, and then same situation as before the vacuum pump. we tested the booster by using vacuum from our iron duke truck and it worked. so should I hook the vacuum pump up the 1st way ?

any tips/tricks? obviously something is screwy

thanks !

 

[Injectedcutty]

I have mine hooked up with the exhaust port on the pump left open. I have the line running from the other port directly to the booster.

I don't have the engine tied into at all and mine works as intended.

If you need pics just lemme know man!

 

[6spdg37s]

I have mine hooked up with the exhaust port on the pump left open. I have the line running from the other port directly to the booster.

I don't have the engine tied into at all and mine works as intended.

If you need pics just lemme know man!

so how long does the pump have to run before u have a normal pedal ?

also does vacuum get used or does it essentially just stay once built... like if i step on the brakes more am i using more vacuum or is it staying at roughly the same ?

Also why would they tell u to hook it up to the manifold I feel like u run the risk of the motor pulling the vacuum away from the booster.

whats also weird is i have a 242/248 ... .612/.615 110LSA cam in my 01 SS and I have 0 vacuum issues the cam in this monte is smaller

 

[565bbchevy]

I am not using an electric pump but instead I am using pulley driven one but I did consider one of these.
The pump itself has a quick recovery time to build up vacuum once it comes on the point of using manifold vacuum is so the pump has a source to see when vacuum is low and as soon as it drops below a preset level it kicks on.
There is an inline check valve that keeps the pump from pulling vacuum from the intake source.
If you follow the instructions the pump will only come on with the ignition on and if vacuum drops below the preset level, if you are just cruising around the pump will not be running until vacuum drops when you hit the brakes.
Also I still recommend that you use a inline vacuum canister so you have a added amount of stored vacuum.

 

[Injectedcutty]

The pump will run until the internal shutoff valve reaches 22" of vacuum. It shouldn't take 20-30 seconds give or take to build. The vacuum will stay until you hit the brakes enough for it to drop below the 16 or 18" threshold, then cycle until it reaches 22 again.

The little i drove my cutlass before the engine pooped out i noticed if i was cruising the pump would shut off, once i applied the brakes it would kick on to keep adequate vacuum, then shut back off.

I'm not sure why they say to hook it into the manifold....i ran it as said above to avoid the engine from pulling the vacuum away from the brakes.

I don't know much about the camaro's, but i would assume it has power brakes instead of vacuum assisted.

As said, my pump has run flawlessly and i did a few panic stops to test it with great stopping power.

 

[6spdg37s]

I am not using an electric pump but instead I am using pulley driven one but I did consider one of these.
The pump itself has a quick recovery time to build up vacuum once it comes on the point of using manifold vacuum is so the pump has a source to see when vacuum is low and as soon as it drops below a preset level it kicks on.
There is an inline check valve that keeps the pump from pulling vacuum from the intake source.
If you follow the instructions the pump will only come on with the ignition on and if vacuum drops below the preset level, if you are just cruising around the pump will not be running until vacuum drops when you hit the brakes.
Also I still recommend that you use a inline vacuum canister so you have a added amount of stored vacuum.

i understand but wouldn't it technically do the same thing if it was hooked directly to the booster as well ? ?

 

[565bbchevy]

i understand but wouldn't it technically do the same thing if it was hooked directly to the booster as well ? ?

In theory yes, but the response time would not be as fast and if you have the added safety of running a vacuum canister the pump would connect to that so it wouldn't come on until it senses it has dropped to 16''-18", but if it is hooked up to the manifold vacuum and it senses a drop in vacuum it will kick on even though you might still have 22" in your canister and once it is wired in to the ignition it is basically a set it and forget it situation.

 

[6spdg37s]

In theory yes, but the response time would not be as fast and if you have the added safety of running a vacuum canister the pump would connect to that so it wouldn't come on until it senses it has dropped to 16''-18", but if it is hooked up to the manifold vacuum and it senses a drop in vacuum it will kick on even though you might still have 22" in your canister and once it is wired in to the ignition it is basically a set it and forget it situation.

gotcha. yeah im gonna play around with it tomorrow and see what happens... i saw the summit vacuum canister for like 36 bucks so i guess i will grab that. but i have seen people run them without having a vacuum canister and had no problem so of course an always why me situation where it doesn't work for me.


I wired it to a relay so that it triggers with ignition on.

 

[565bbchevy]

gotcha. yeah im gonna play around with it tomorrow and see what happens... i saw the summit vacuum canister for like 36 bucks so i guess i will grab that. but i have seen people run them without having a vacuum canister and had no problem so of course an always why me situation where it doesn't work for me.I wired it to a relay so that it triggers with ignition on.

Most electric vacuum pumps will work fine without a vacuum canister but I feel it is cheap insurance having the added safety protection for braking and the more power you add to your car the more stopping power you will be relying on from your brakes

 

[Injectedcutty]

Most electric vacuum pumps will work fine without a vacuum canister but I feel it is cheap insurance having the added safety protection for braking and the more power you add to your car the more stopping power you will be relying on from your brakes

Yep....i plan on adding the can inline with my electric pump as a "just in case" thing. Our cars can never have enough vacuum reserve, especially with higher lift cams!