Mercedes Benz C 43 AMG Technical Service Bulletin # P-20_10-23 Date: 030507

Mercedes Benz C 43 AMG Technical Service Bulletin # P-20_10-23 Date: 030507

Cooling System - Water Pump Leakage

Date: May 7, 2003

Order No.: P-B-20.10/23

Supersedes:

Group: 20

SUBJECT:

All Models with 112 or 113 Engine

Water Pump Leaking

If you receive customer reports of the water pump leaking on any 112 or 113 engine vehicle, replace the water pump only if it is clearly visible that

coolant drips continuously from the vent hole.

Traces of coolant residue and wetness (formation of droplets) at the vent hole of the water pump are normal and therefore are not considered

"leakage". Water pump replacements under such conditions are therefore not justified.

A small amount of coolant in the groove of the pump seal is required for lubrication of the pump. Coolant droplets forming at the vent hole dry up

and leave a distinct residue due to the high content of solid matter in the coolant (6g/100cc). This is particularly obvious on vehicles used for short

distance driving with the engine being started and stopped frequently.

Water pumps returned for leaking coolant will be checked very carefully and warranty claims might be debited if a pump is found to be in acceptable