Testing Cylinders For Leaks

- Warm up engine to operating temperature.
- Disconnect ground cable at battery.
- Remove spark plugs.
- Open cap on coolant expansion reservoir.

WARNING: Do not open cap unless coolant temperature is below 90°C. Risk of scalding!

- Adjust coolant level to correct level.
- Open oil filler cap.
- Connect cylinder leak tester to compressed air system.
- Calibrate tester.
- Screw in connection hose to first spark plug hole.
- Position piston of cylinder to be tested with adjuster by turning crankshaft to ignition TDC.
See see table below for piston in TDC .
- Connect connection hose of tester
- Pressurize combustion chamber.
The crankshaft must not rotate; if necessary secure crankshaft with locking device to prevent it from rotating.
- Open throttle valve by hand.
- Read off pressure loss on tester in %.
- Determine whether pressure leak is through intake manifold, exhaust, oil filler opening, spark plug hole of adjacent cylinder, or coolant filler opening (at reservoir).
- Test all cylinders in firing order (1-5-4-8-6-3-7-2).

Specifications
- Total Pressure Loss: Maximum 25%
- At Valves and Cylinder Head Gasket: Maximum 10%
- At Pistons and Piston Rings: Maximum 20%

Piston Position Table
- Marking index on dampner: 0
Pistons in TDC: 1 and 6
- Marking index on dampner: 90
Pistons in TDC: 5 and 3
- Marking index on dampner: 180
Pistons in TDC: 4 and 7
- Marking index on dampner: 270
Pistons in TDC: 8 and 2

Commercially Available Tool
- Cylinder leak tester:
Bosch, Tool No. EFAW 210A
Sun, Tool No. CLT 228