Join Date: Sep 2018
Location: Southern Maryland, U.S.A
Vacuum brake booster testing
So I have installed a new Wildwood master cylinder, all new stainless hard lines and stainless flex lines at calipers and all new rear disc conversion (The Right Stuff). I have bled the brakes and all seems good. But when the car is running, my pedal goes to the floor. At that point, then the brakes will engage and work, but I'm guessing that's beyond the power assist portion of the pedal travel.
The only thing that is old in this system is the Delco 11" vacuum brake booster. When I purchased the '66 in 1990, it was there.
When I use a MityVac vacuum pump and hook it up to the vacuum hose going to the brake booster, I can't draw any vacuum, gauge stays at zero. Should I be able to?! I found one post in the internet that indicates I should be able to, but want to confirm. If so, then that would confirm my booster is bad.
Otherwise, maybe my master cylinder is bad (brand new!). Or I have issues with the pushrod...though when I installed this thing many months ago, I was sure I got that all right.
1966 Chevelle SS, 355 V-8, TH-350.