Hi, the reason for starting this new thread is because I have read all the related items in the forum and have found no info to help me. Like many others I have a car with a totally rebuit braking system and have good brakes but there is one problem as follows:
when the pedal is initially depressed it hangs up and then with a little more pressure the brakes come on fast, not good for driving in traffic.
At first I thought it was the air valve coming too late to release vaccuum on the back of the booster. So I put a vaccuum gauge in the line from the airvalve to the booster which seemed to confirm that the valve was late but what confused me was that the system was operating at only 1" Hg making it difficult to really see any change. Checking the vaccuum coming out of the manifold it was also only 1" Hg, using another port without the non return valve gave 15" Hg and running the brakes at this vaccuum level seemed to show significant improvement. Hmmm, has the non return valve failed and why are there two valves in the system?
My question is what level of vaccuum is the system designed for and has anyone checked what the vaccuum is on a car deemed to have a brake system functioning properly?
Owen Evans
1970 Nada 3500s
1980 SD1
1975 Bricklin SV1
when the pedal is initially depressed it hangs up and then with a little more pressure the brakes come on fast, not good for driving in traffic.
At first I thought it was the air valve coming too late to release vaccuum on the back of the booster. So I put a vaccuum gauge in the line from the airvalve to the booster which seemed to confirm that the valve was late but what confused me was that the system was operating at only 1" Hg making it difficult to really see any change. Checking the vaccuum coming out of the manifold it was also only 1" Hg, using another port without the non return valve gave 15" Hg and running the brakes at this vaccuum level seemed to show significant improvement. Hmmm, has the non return valve failed and why are there two valves in the system?
My question is what level of vaccuum is the system designed for and has anyone checked what the vaccuum is on a car deemed to have a brake system functioning properly?
Owen Evans
1970 Nada 3500s
1980 SD1
1975 Bricklin SV1
