Check cylinders for leaks

AR01.00-P-1300LFB

Check cylinders for leaks

12.12.2019

Engine

157, 276, 278 in model 217

Engine

157, 276, 278 in model 222

Modification notes

04.12.2019

Special tool 450 589 17 21 00 added.

Shown on engine 278

01

Pressure loss tester

 Caution

Risk of injury to skin and eyes due to handling of engine oil. Risk of poisoning caused by swallowing engine oil

Wear protective gloves, protective clothing and safety glasses.
Do not fill engine oil into beverage containers.

AS18.00-Z-0001-01A

 Warning

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

 Warning

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

 Warning

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

Determine loss of pressure at cylinder

AH01.00-N-1300-02A

 

Remove/install

1

Bring engine to operating temperature (approx. 80 °C) and switch off engine.

 Only check cylinder leakage when the engine is at normal operating temperature.

2

Switch off ignition and remove transmitter key.

3

Slowly unscrew cap from coolant expansion reservoir.

4

Take off oil filler cap.

5

Remove spark plugs.



Engine 157, 276, 278 in model 222
Engine 157, 278 in model 217

AP15.10-P-1580HA



Engine 276.8 in model 217

AP15.10-P-1580D

6

Remove charge air line from charge air cooler.

Engine 276.8 in model 217, 222

AR09.41-P-6819LFA

7

Unclip charge air cooler from lower retaining clamp and pull forward.

Engine 276.8 in model 217, 222

AR09.41-P-6819LFA

8

Position piston of cylinder to be checked at top dead center (ignition TDC) using a TDC detection device.

 Crank engine at crankshaft center bolt in direction of engine rotation.

 Socket wrench bit

*001589650900

9

Connect pressure loss tester (01).

AR01.00-P-1300-01VA

 Pressure loss tester

*450589172100

 Screw-in fitting

*270589019100

10

Apply compressed air to the cylinder and read off pressure loss from pressure loss tester (01).

Cylinder leaktightness: Permissible losses at pistons and piston rings

*BE01.00-P-1003-02Z

Cylinder leaktightness: Permissible losses at valves and cylinder head gasket

*BE01.00-P-1002-02Z

Cylinder leakage: permissible loss total indication

*BE01.00-P-1001-02Z

 Pressure loss tester

*450589172100

11

Check other cylinders in firing order of engine.

AR01.00-P-1300-03MM

 See "Firing order of the respective engine".

12

Install in the reverse order.

Cylinder leakage

Number

Designation

Engine all (4xWD, CAR, smart)

BE01.00-P-1001-02Z

Cylinder leakage: permissible loss total indication

%

 25

Cylinder leakage

Number

Designation

Engine all (4xWD, CAR, smart)

BE01.00-P-1002-02Z

Cylinder leaktightness: Permissible losses at valves and cylinder head gasket

%

 10

Cylinder leakage

Number

Designation

Engine all (4xWD, CAR, smart)

BE01.00-P-1003-02Z

Cylinder leaktightness: Permissible losses at pistons and piston rings

%

 20