Mazda B Series Truck 2WD L4 Workshop Service and Repair Manuals

Fuel Pressure Check Valve: Testing and Inspection

Fuel Check Valve

1.

Remove check valve from fuel return line.

2.

Blow through valve in both directions. Verify that air flows from "A" to "B" and not from "B" to "A". 

If air flows both directions or does not flow from "A" to "B", replace check valve.