TESTING

1. Attach a clean rubber hose to both sides of the pressure relief valve.
2. Blow lightly from the inlet side of the valve and the air should pass through after a slight resistance is felt.
3. Blow lightly from the outlet side and the air should not pass through.
4. If the valve fails either of these tests, replace it with a new unit.

   Fig. 1: Check the fuel pressure relief valve by blowing through it in each direction