Cory9584

Does anybody make a valve that will allow pressure through but no vacuum?

KuHL 951

Depending on the size you need there's the vac check valve on the brake booster. It's the blue valve in-line w/ the booster. There are larger aftermarket ones depending on your requirements.

Vac Check Valve

Cory9584

I tried that but it didnt work, it's meant to let vac through and no pressure. I dont think it works as efficiently the other way around. I tried blowing through it and it was good but when you apply strong vacuum it still pulls through.