HV3 - Check Vacuum Fuel Tank to Canister

- Remove fuel vapor hose at canister.

- Install a vacuum tee in the hose and add small pieces of vacuum hose to the other two ends of tee.

- Install a vacuum gauge in the second end of the tee.

- Install a vacuum shut off valve in the third end of the tee.

- Add a small piece of hose (with a plastic straight fitting at one end) to free end of the shut off valve.

- Apply 0.75 psi maximum vacuum to the plastic straight end with a hand held vacuum pump.

- Close the shut off valve and monitor the vacuum gauge.

- Is the fuel tank to canister system holding vacuum or fuel pressure?

YES -- Fuel tank, fuel vapor hose and gas cap indicate no leaks. REMOVE vacuum gauge and vacuum pump. RECONNECT carbon canister. Go to HV4. HV4 - Check CANP For Vacuum Leaks - Closed Vacuum Position

NO -- SERVICE as necessary the fuel pressure leak or EVAP vacuum leak (gas cap, vapor orifice rollover valve, fuel vapor hose or fuel tank). REPEAT vacuum check on this part of the system to verify repair.