Is checkvalve necesary?

[stevebez]

I have HFS6 with jets installed in off boost vacuum area. Is the HFS6 system "water tight" when off, or is a vacuum check valve needed?

Rgds Steve

[Richard L]

Hello Steve,

A check valve will help if your jets are wide apart, stopping the siphoning-off effect due inbalance of vacuum betwem the two injectionpoints. The HFS-6 is water tight at the off position. the fluid is shut off by an inline solenoid valve.