Diesel Fuel System - Fuel Loss/Odors

Date: September 4, 2007

Order No.: P-B-07.16/76

Supersedes:

Group: 07

SUBJECT:
Model 211.022/026

Leaking High Pressure Fuel Pump / Possible Fuel Loss/Odor

In the event of a leak in the high-pressure fuel pump, and possible fuel loss/odor, the following potential causes and remedies are available.

Note:
The coolant hoses and poly-v belt must always be checked for fuel contamination. If contaminated with fuel, they must be replaced.

Cause 1:

The hose/low pressure connection fitting assembly may leak especially at low outside temperatures.

Note:
If old version of Clic clamps (yellow tabbed) are used, the preload force is too low. Replace the Clic clamps (stainless steel).

Remedy 1:

If high-pressure pump is found to be leaking at the low-pressure connections, then only the Clic clamps and the fuel feed and return hoses must be replaced.

Retightening the low-pressure connections is NOT permissible and will cause leakage. It is not permissible to use screw clamps due to lack of tension reserves.

If after the above repair a leak still persists on Model 211.026, the low pressure hose fittings and 0-rings should be replaced. On Model 211.022, the low pressure hose fitting cannot be replaced; in this case, the high pressure pump should be replaced.

If the high-pressure pump is leaking at the quantity control valve, then the 0-rings should be checked and replaced individually if damaged. Should the quantity control valve be defective in itself, then this can be replaced separately. In this case, DO NOT replace the high pressure pump.

Cause 2:

Leakage from high-pressure pump itself.

Remedy 2:

The pump should be replaced with the leak marked.

In order to localize the leak on the high-pressure pump, always clean the high-pressure pump and spray it with MB leak detector spray.





Upon replacing the high-pressure pump, the leak should be marked on the pump and on the associated drawing and evaluated. The drawing with the identification of the leak and the evaluation of the leak should be sent back with the old part.





Parts Information

Note:
The following allowable labor operations should be used when submitting a warranty claim for this repair. This information has been generated on September 4, 2007. Please refer to Netstar --> Star TekInfo --> Star Time for the most current labor time allowance.





In Case of Warranty, use the table.