Fuel prefilter with water separator - replacing filter element

AP47.20-B-0783B

Fuel prefilter with water separator - replacing filter element

25.11.2019

Engine

376.9, 377.9

Engine

457.9 in model 000, 374, 375, 400, 693, 695, 696, 934, 940, 942, 943, 944, 949

Engine

904.9, 906.9 in model 000, 374, 375, 685, 950, 952, 953, 954, 957

Engine

924.9, 926.9 in model 000, 949, 950, 952, 953, 954, 957

Represented on engines OM 374.9, 376.9, 377.9, 457.9

1

Cylinder head

2

Seal ring

3

Filter element

4

Seal ring

5

Transparent bowl

6

Drain plug

A

Vent plug

1

Cylinder head

2

Seal ring

3

Filter element

4

Seal ring

5

Transparent bowl

6

Drain plug

Represented on engines OM 904.9, 906.9, 924.9, 926.9

A, B

Engine start and stop switches



Remove

 Danger

Risk of explosion caused by fuel igniting, risk of poisoning caused by inhaling and swallowing fuel as well as risk of injury to eyes and skin caused by contactwith fuel.

No fires, sparks, open flames or smoking. Pour fuels into suitable and appropriately marked containers only.
Wear protective clothing when handling fuel.

AS47.00-Z-0001-01A

1

Remove the vent plug (A)

 Access to carry out maintenance and repair jobs in buses varies according to body type/ make
See the body manufacturer instructions.

2

Drain the fuel through the drain plug (6)

 On engines 376.9 and 377.9, there are fuel filter models without the transparent bowl

3

Remove the filtering element (3) together with the transparent bowl (5), and the sealing ring (2)

4

Separate the transparent bowl (5) from the filtering element (3), and from the sealing ring (4)



Install

5

Clean the transparent bowl (5)

 Utilize clean diesel oil.

6

Install the transparent bowl (5) on the filtering element (3)

 Use a new filtering element . Oil the sealing ring with clean engine oil.

7

Tighten the drain plug (6)

8

Install the filtering element assembly in the cylinder head (1)

 Fill, beforehand, with clean diesel oil. Oil the sealing ring (2) with clean engine oil. Hand-tighten the assembly firmly.

9

Bleed the fuel system

Engine 376.9

AP47.00-B-1720-01E

Engine 904.9, 906.9, 926.9

AP47.00-B-1720-01C

Engine 457.9

AP47.00-B-1720-01D

 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

10

Start the engine and check the fuel system for tightness

 Do not crank the engine continuously for more than 30 seconds. If the engine does not fire within this interval, wait approximately 1 minute to crank it again.

 Engines 904.9; 906.9; 926.9: Engine startup and shutdown can be carried out by means of the switches (A, B).