Component Tests and General Diagnostics

17 00 009 - Checking cooling system for water leaks





Special tools required:
- 00 2 030 00 2 030 Universal Hydro-Lifter Basic Unit
- 17 0 101 17 0 100 Tester
- 17 0 113 17 0 100 Tester
- 17 0 114 17 0 100 Tester






Warning!
Danger of scalding!

Only perform this work after engine has cooled down.





Protective measures/rules of conduct:

- Wear protective goggles
- Wear protective gloves
- Observe national/country-specific regulations






Important!
Risk of slipping due to coolant on the floor.

Danger of injury!

Catch and dispose of drained coolant in drip tray (1) and if necessary special tool 00 2 030 00 2 030 Universal Hydro-Lifter Basic Unit (universal hydraulic lifter).

Recycling:
Observe country-specific waste-disposal regulations.





Checking pressure drop in cooling system:

Open cap on coolant expansion tank. Fit special tools 17 0 101 17 0 100 Tester/ 17 0 113 17 0 100 Tester.

Build up gauge pressure 17 11 Radiator and Mounting Parts, wait approx. 2 minutes.

Cooling system is impervious to leaks if pressure drop is max. 0.1 bar.





Checking pressure relief valve in cap:

Note:
While the vehicle is driven at high outside temperatures, the design may cause the pressure relief valve in the cap to open slightly and air together with dissolved coolant to escape. This coolant vapour condenses on the surface of the expansion tank and leaves traces when the vehicle has cooled down. These traces do not indicate whether the cap is defective or not. When the vehicle has been parked up for an extended period of time, the residual escaping coolant can cause the pressure relief valve in the cap to stick; therefore check the cap again 2 to 3 times.

Replace the cap only after you have checked three times and there is an incorrect opening pressure.





Checking pressure relief valve in cap:

Screw cap (1) onto special tool 17 0 114 17 0 100 Tester.

Build up pressure with special tool (hand pump) 17 0 101 17 0 100 Tester; observe pressure gauge to ascertain when opening pressure is achieved.

Compare opening pressure of pressure relief valve 17 11 Radiator and Mounting Parts.