Testing the fuel cap

• Remove fuel cap.

Fig 1: Fuel Cap Receiver Connect To Hose

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Connect fuel cap receiver (arrow) to hose.
• Screw fuel cap tightly to cap receiver.
• Turn control valve to "Test" pressurizing cap.
• Turn valve to "Hold".

• Watch pressure gauge for drop in pressure from 14 inches H ₂ O.

If no pressure drop is indicated:

• Proceed to checking Leak Detection Pump (LDP) V144 for internal leaks.

If pressure drop is indicated:

• Replace fuel cap and re-test.
• Proceed to Checking Leak Detection Pump (LDP) V144 for internal leaks.