coolant loss - PeachParts Mercedes-Benz Forum

chisholm · #1 08-23-2003, 10:39 AM

After my Saturday morning drive I found a stream of coolant dripping off the front of my '85 300D's oil pan. The coolant is not coming from the water pump weep hole nor does it appear to be coming from the thermostat housing - somewhere between the top of the water pump and the top of the oil pan on the front of the engine. The radiator and hose clamps appear dry. Any suggestions?

How do I go about determining if my water pump is dying or dead?

Matt Chisholm

Stevo · #2 08-23-2003, 11:47 AM

I'm placing my bet on the water pump needing replacing. I think I would clean off the front of the engine good and maybe you will be able to see the sorce of the leak better.

chisholm · #3 08-23-2003, 09:05 PM

I have replaced the water pump. There was not much sign of a gasket between the old pump and its housing. Where did it go? I searched the forum for useful tips on what needed to be removed to get at the pump and what to do before installing the new pump. I cleaned off the mating surfaces before putting the sealant coated gasket on the pump. The only problem I had was with the alternator. I loosened the pivot bolt from under the car and then tried to wound out the adjustment bolt from under the hood. After seeing I was bending the adjustment bolt brace (?), I removed the two through-bolts to free the alternator. After the loss of a lot of sweat and a few curse words, the alternator, water pump, belts and pulley are back in place.

I still have to readjust the alternator to tighten the belts, replace the fan and its shroud and then add the coolant. At least it is cooler now.

Stevo · #4 08-24-2003, 12:51 AM

Matt

Let us know, but I think most of the time when coolant shows up where you described the water pump is the culprit.

Steve

chisholm · #5 08-24-2003, 09:02 AM

After finishing the water pump replacement last night, I took 300D out for a test drive. All went well. And this morning after another shorter drive I still see no coolant. The leak must have been the water pump. Any ideas on where the pumps leak? The only thing that looked suspicious to me was the disolved (?) paper gasket.

Stevo · #6 08-24-2003, 10:34 AM

Humm "Any ideas on where the pumps leak? "

I am still fairly new at this. good question for the "older" timers. The first one I replaced was like yours, the second one started making noise. As for the alternator...I use a pinch bar to get the slack out of the belt on my "79", gave up on the adjuster thingie.

Steve