I have a 98 z28 that I put a cam in and for some reason now the brake pedal is very hard. I replaced the booster just to see if that was it and noticed there is no vacuum coming from the hose that goes into it. Is there anything that would make this have no vacuum going to it? Thanks, Paul.

 

How big is the cam? High overlap on the cam reduces manifold vacuum. Low vacuum reduces the effectiveness of the brake vacuum booster.

 

It's a trex cam so it's big, if there is no vacuum should I find a vacuum pump and has anyone heard of having to do this with that cam?

 

I installed an electric vac pump due to low manifold vac from a blower FI app. You need approx 16" Hg for the brake booster assist. Summit racing.com has kits (SSBC CCP etc.) I have only 3" Hg @ idle and about 10" @ low speed cruz part throttle. Vac pumps work fine but can add some noise depending where you install them. I have been running it for 3+ years with good success. (97ss 383 D1 MM6) B.