Check cylinders for leaks

AR01.00-D-1300WE

Check cylinders for leaks

09.12.2013

ENGINE

651 in MODEL 636, 639

ENGINE

651 in MODEL 900

ENGINE

651.955/956/957 in MODEL 906

Shown on model 906

1

Screw-in piece

2

Cylinder leakage tester

3

Oil filler cap

 Danger !

Risk of injury. Skin or eye injuries may result when handling hot or glowing objects.

Wear protective gloves, protective clothing and safety glasses, if necessary.

AS00.00-Z-0002-01A

 Danger !

Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.

Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.

AS00.00-Z-0005-01A

 Danger !

Risk of injury to skin and eyes suffering scalding from contact with hot coolantspray. Risk of poisoning from swallowing coolant.

Do not open cooling system unless coolant temperature is below 90 °C. Open cap slowly and release the pressure. Do not pour coolant into beverage containers.
Wear protective gloves, protective clothing and safety glasses.

AS20.00-Z-0001-01A

 

Remove/install

1

Start engine and warm up to an operating temperature of approx. 80°C

 Only check for cylinder leakage when the engine is at normal operating temperature. After reaching the engine operating temperature and switch off ignition.

2

Unscrew cap of the coolant expansion reservoir

 To do this turn cap for coolant expansion reservoir half a revolution counterclockwise, release overpressure and subsequently unscrew.

3

Remove glow plugs

ENGINE 651 in MODEL 900
ENGINE 651.955/956/957 in MODEL 906

AR15.20-D-4111WE

ENGINE 651 in MODEL 636, 639

AR15.20-S-4111SJ

4

Position piston for cylinder to be checked at ignition TDC

 To do this turn engine on crankshaft in direction of engine rotation and position piston of cylinder to be checked at ignition TDC with aid of the TDC location device. Use aid of helper. TDC detector is included in package contents of cylinder leakage tester (2).
Commercially available tools
Cylinder leakage tester (pressure loss).

 Counterholder

*651589004000

 Counterholder

*651589074000

 Counterholder

*651589084000

5

Screw in screw-in piece (1) into the glow plug hole of the cylinder to be checked.

 Screw-in fitting

*640589006300

 Screw-in fitting

*642589006300

 Screw-in fitting

*642589026300

6

Connect cylinder leakage tester (2) to screw-in piece (1)

 Calibrate cylinder leakage tester (2).

 Screw-in fitting

*640589006300

 Screw-in fitting

*642589006300

 Screw-in fitting

*642589026300

7

Remove oil filler cap (3)



Check

8

Charge cylinder with compressed air and read off pressure loss on cylinder leakage tester (2)



Determine loss of pressure at cylinder

AH01.00-N-1300-02A

Cylinder leakage: permissible loss total indication

*BE01.00-P-1001-02Z

Cylinder leaktightness: permissible losses at valves and cylinder head gasket

*BE01.00-P-1002-02Z

Cylinder leaktightness: permissible losses at pistons and piston rings

*BE01.00-P-1003-02Z

For increased pressure loss:



Determine cause.

Secure crankshaft against twisting, if necessary, see:



Remove/install retaining lock for crankshaft/ring gear
ENGINE 651 in MODEL 636 with TRANSMISSION 711.6 ENGINE 651 in MODEL 639 with TRANSMISSION 711.6, 722.6

AR03.30-S-5000SJ

Remove/install retaining lock for crankshaft/ring gear
ENGINE 651 in MODEL 900
ENGINE 651.955/956/957 in MODEL 906

AR03.30-D-5000WE

9

Check further cylinders in firing order in same manner

AR01.00-S-1300-03SD

10

Install in the reverse order

Cylinder leakage

Number

Designation

ENGINE ALL

BE01.00-P-1001-02Z

Cylinder leakage: permissible loss total indication

%

25

Cylinder leakage

Number

Designation

ENGINE ALL

BE01.00-P-1002-02Z

Cylinder leaktightness: permissible losses at valves and cylinder head gasket

%

10

Cylinder leakage

Number

Designation

ENGINE ALL

BE01.00-P-1003-02Z

Cylinder leaktightness: permissible losses at pistons and piston rings

%

20