Checking the Cooling System For Leaks

Tools

Checking the cooling system for leaks

Note: Perform the leak test only on a cold engine.





1. Remove cap and attach tester.





2. Pump the cooling system up to an excess pressure of 1.3 bar. If the pressure decreases, locate the leak and remedy the fault. Check pressure relief valve(s) in the cap. Screw the tester, adapter and cap together.

Test, two-step cap
Part number 996 106 447 00
1. Generate excess pressure (step 1)
2. The pressure relief valve opens at an excess pressure of approximately 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.
3. If the test pressure of step 1 is maintained, test step 2. Apply excess pressure to the pressure relief valve of step 1 by pumping rapidly. The pressure relief valve of step 2 must open at an excess pressure of approximately 1.8 bar. If the valve does not open, replace the cap.