Brake problem

Reply Subscribe

Thread Tools

Search this Thread

10-22-2009, 09:57 AM

Camaroz28lt1383

Registered User

Thread Starter

Join Date: Nov 2002

Posts: 102

Brake problem

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.

10-22-2009, 10:48 PM

Injuneer

Administrator

Join Date: Nov 1998

Location: Hell was full so they sent me to NJ

Posts: 70,646

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

10-23-2009, 02:11 PM

Camaroz28lt1383

Registered User

Thread Starter

Join Date: Nov 2002

Posts: 102

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?

10-24-2009, 01:23 AM

mzgp5x

Registered User

Join Date: Jul 2004

Location: MI

Posts: 1,174

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.