Vacuum Check Valve

Suit All Nissan Patrol GQ And GU Models

This is an Inline One way valve that goes in the brake and clutch vacuum hoses.

different models have them in different locations, but the best working system has one on the brakes vacuum line and another one on the clutch line, you can also put one between the vacuum canister and the vacuum pump.

the benefit of having one way valves is if there is a leak anywhere in the system, it isolates it from affecting all of the componentry.

if you are chasing a vacuum issue, it is also common for the rubber hoses to go hard and not seal properly at the clamps