Checking Cylinders For Leaks

Data
Total pressure loss max. 25%
On valves and cylinder head gasket max. 10%
On pistons and piston rings max. 20%


Checking
1 Run engine up to 80 °C coolant temperature.
2 Unscrew pencil element glow plugs.
3 Remove air cleaner cap.
4 Remove oil filler plug.
5 Remove radiator cap and top up coolant.






6 Enter screw fitting into glow plug bore of 1st cylinder.






7 Set piston of 1st cylinder to ignition TDC. For this purpose, rotate engine at crankshaft by means of tool combination.
8 Connect cylinder leak tester to a compressed air system. Calibrate tester.
9 Screw connecting hose of tester to screw fitting. Crankshaft should not rotate.






10 Read pressure loss on tester.
11 Check by listening whether pressure escapes via intake pipe, exhaust, oil filler cap, glow plug bore of adjacent cylinder or radiator cap.
12 Check all cylinders in ignition sequence.

NOTE: There is the possibility that the piston ring gaps of individual pistons are directly one above the other, so that the test result will be misrepresented.

When in doubt, continue running vehicle and check cylinders for leaks once again later on.