Test compression pressure

AR01.00-B-1200DD

Test compression pressure

08.01.2020

Engine

906.99 in model 958

Engine

924.92 in model 384.2/3

Engine

926.94 in model 958

1

Nozzle holder combination

2

Bolt

4.1

Connector

4.2

Safety clamp

5

Seal ring

6.1

Compression test equipment

6.2

Diagram map



Remove

 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

1

Adjust valve clearance



Set valve clearance

.

AP05.30-B-0560B

 Adjust the valve clearance only when engine is cold, at least 30 minutes after shutting down the engine.

2

Heat the engine to the normal operating temperature

 Coolant temperature, approx. 70 to 95 °C.

3

Remove combinations of nozzle holders (1)

AR07.03-B-6831DD

4

Install connector (4.1), safety clamp (4.2) with screw (2)

 Attachment support of the cylinder head injector

*BA07.15-B-1003-01A

 Connector

*904589012100

5

Insert the compression pressure recorder (6.1) into the connector (4.1).

 Compression pressure recorder connection (6.1). Refer to the equipment manufacturer's operating manual.

 Compression tester

*001589782100

 Connector

*904589012100

6

Insert tachograph disk (6.2) into compression pressure recorder (6.1)



Check

7

Turn the engine with starter

 Turn the engine for at least 8 revolutions.

8

Inspect the remaining cylinders the same way

9

Compare the measurements on chart (6.2) with the specified measurements



Minimum permissible compression pressure (at seal level)

*BE01.00-B-1001-01C

Maximum variance between the cylinders of an engine.

*BE01.00-B-1002-01C

If the measured pressure is below the minimum compression pressure or if the allowable difference is exceeded:



Determine and eliminate the cause.

Remove/install cylinder head
.

AR01.30-B-5800DD



Install

10

Remove the compression pressure recorder (6.1) and the connector (4.1) along with the sealing ring (5)

11

Install combinations of nozzle holders (1)

AR07.03-B-6831DD

Compression

Number

Designation

Engine 904.9, 906.9

Engine 924.9, 926.9

BE01.00-B-1001-01C

Minimum permissible compression pressure (at seal level)

bar

28

28

Compression

Number

Designation

Engine 904.9, 906.9

Engine 924.9, 926.9

BE01.00-B-1002-01C

Maximum variance between the cylinders of an engine.

bar

4

4

 Diesel injection system with injection unit (MR/PLD)

Number

Designation

Engine 904.9, 906.9, 924.9, 926.9

BA07.15-B-1003-01A

Attachment support of the cylinder head injector

12 corners with spheric collar

Nm

35

Inside hexagonal

Nm

30