Mileage is not the only factor causing water pump to start leaking. The age of the car is as well. Seals dry out in time. The water pump has a weep hole in the shaft right behind the seal. Do you see coolant dripping form that weep hole?
Im more than 90% sure that the coolant is comming from the water pump...because it drips down on top of the oil pan, and onto the floor directly underneath...its not much, but it seems every other day Ive been adding water, and when this water pump repair is made, Ill replace it with some non green MB coolant....All the hoses are good, radiator is tight and all the cooling connections on the front of the motor are tight...so im left with the pump
Replacing the water pump on an 80's diesel Mercedes is simple because only the water pump cartridge, not the whole housing, is replaced. It is readily accessible from the front.
One snag you will run into is breaking loose the clutch fan bolts. The problem with those is that you need a modified 10 mm box end wrench to slip it over the bolts. This is done by taking long 10 mm box end wrench and grinding off some metal from the end of the wrench box to enable it to slip over the fan clutch bolts.
Always break the bolts loose before loosening the drive belt! You can do it with the open end of your 10 mm wrench, but be careful not to round off the bolts.
Another nasty surprise comes when you unbolt the old pump and break it loose. You get a torrent of coolant rushing out. Even with the radiator drained! Make sure you place some plastic over the alternator to prevent the coolant from getting into it, and have a large pan under the car ready to catch the spilled coolant.
Use a small amount of silicone sealant (or anaerobic sealant) on the new water pump gasket. Be careful not to overtighten the fan clutch bolts and I recommend you pup some blue LokTite on the threads before assembly. For the water pump bolts, coat the bolt threads sparingly with neverseize grease.
BenzWorld.org forum is one of the largest Mercedes-Benz owner websites offering the most comprehensive collection of Mercedes-Benz information anywhere in the world. The site includes MB Forums, News, Galleries, Publications, Classifieds, Events and much more!