Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2004 Porsche Boxster Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Test, Two-Step Cap
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.
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.