1 | Injector holder |
2 | Injection unit |
3 | Electric wires |
5 | Seal ring |
6 | Adapter |
7 | Support |
8 | Compression recorder |
20 | Drain tube |
S10 | Engine stop switch |
S11 | Engine stop switch |
B01.00-0018-06
Check | |||
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. | |
1 | Conduct a preliminary assessment (electronically) of the engine compression by using the Minitester, HHT or Star Diagnosis devices | Identify two cylinders; the best and worst performing ones. | |
2 | Check the effective compression of the two cylinders identified and evaluate their actual conditions. | ||
3 | Check and, if necessary, adjust the clearance of the valves | ||
| Engines 904.9, 906.9, 924.9, 926.9 | . | |
| Engines 457.9 | . | |
4 | Run the engine until it reaches operating temperature, then shut it down | Nominal temperature | |
5 | Remove the injector holder (1) from the respective cylinder to be tested |
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Engine 904.9, 906.9, 924.9, 926.9 | |||
6 | Disconnect the electrical cables (3) from all injection units (2) | Avoid the action of the injection units. Insulate the electrical cable terminals. | |
7 | Install the drain pipe (20) in the injection unit (2) | This is necessary to prevent fuel spillage when cranking the engine. | |
Pump | |||
8 | Crank the engine for about 5 seconds by using the starter, while actuating the start (S10) and stop (S11) switches | For vehicles not equipped with auxiliary switches, start the engine using the contact switch. | |
This operation is intended to expel any combustion residues from inside the cylinder. | |||
9 | Mount the adapter (6) on the injection nozzle housing, secure it with the bracket (7) and connect the compression recorder (8) | Mount the adapter (6) with the gasket (5) and tighten the bracket screw to the prescribed torque. | |
Engine 457.9Injector fastening support to cylinder head | |||
Engine 904.9, 906.9, 924.9, 926.9Attachment support of the cylinder head injector | |||
Compression tester | |||
Connector | |||
10 | Crank the engine for by using the starter, while actuating the start (S10) and stop (S11) switches | For vehicles not equipped with auxiliary switches, start the engine using the contact switch. | |
Run the engine until the pressure indicated on the recorder stabilizes. At least 8 turns of the engine. | |||
11 | Check the compression of the other cylinder, following the steps above | Depressurize (purge) the recorder before starting a new check. | |
12 | Compare the values achieved with the specified values | Maximum variance between the cylinders of an engine. | |
Minimum permissible compression pressure (at seal level) | |||
In case of inconsistency, remove the head and check the cause. | |||
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13 | Install in reverse order |
001 589 78 21 00
Compression tester
904 589 01 21 00
Connector
422 589 01 71 00
Pump
Referenced documents
- ap0530b0560b Set valve clearance
- ap0530b0560g Set valve clearance
- ar0130b5800b Remove/install cylinder head
- ar0130b5800f Remove/install cylinder head
- ar0130b5800j Remove/install cylinder head
- ar0703b6831a Remove/install nozzle holder combination
- ar0703b6831b Remove/install nozzle holder combination
- as0000z000501a 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.