Test, Two-Step Cap

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2004 Porsche Boxster, 2003 Porsche Boxster, 2002 Porsche Boxster, 2001 Porsche Boxster, and 2000 Porsche Boxster. However, it is still accessible from the selected car via links, so may be relevant.

Part number 996 106 447 00

Generate excess pressure (step 1)
The pressure relief valve opens at an excess pressure of approx. 1.4 bar; the pressure then slowly decreases again, and the valve closes at 1.0 bar. If the pressure decreases further, replace the cap.
If the test pressure of step 1 is maintained, test step 2. Apply excess pressure to the pressure relief valve of step one by pumping rapidly. The pressure relief valve of step 2 must open at an excess pressure of approx 1.8 bar. If the valve does not open, replace the cap.