Leakage: H20 Pump, 85 300TDT

[Alec]

Does anyone have experience with fuel pumps on an 85 300TDT (260k)?

Someone suggested that it could be a crack in the block...is this common?

I am loosing coolant from the front of the engine at a slow but steady rate...~1/2 gal/300 miles. It is dificult to tell but it appears to be coming from the vicinity of the water pump. I think it may be the seal around the pump housing and not the shaft seal. I don't think it is a hose leak.

Any input or suggestions before I take the sucker apart .

Thanks for your time,
Alec.

I went through this same thing earlier this summer... It turned out to be a leaking gasket (<$1.00) between the water pump housing and the block. The repair itself was simple, but getting to the repair was rather involved. It involves removing the radiator hoses, radiator, fan shroud, fan, belts, and water pump. Beware: the bottom bolt on the water pump requires an extremely shallow 13mm socket, or an offset wrench - I chose to grind down a socket on the bench grinder. I figured since I had this much already torn down, I would go ahead and replace all of the under hood rubber - 4 belts and 14 hoses. The procedure is not complicated if you don't mind the time it takes to perform it. Hope this helps - Raven

[This message has been edited by Raven (edited 09-28-2000).]

[Alec]

...is it really necessary to remove the radiator? The Haynes Manual indicates that but the M-Benz Service Manual CD dosen't mention it. Can the hoses be ordered as a set?

Thanks,
Alec.

I suppose you could try it without removing the radiator... But since there are only two clips that hold it in place I found it easier to remove it and the fan shroud as opposed to having to work around it. You will need to at least drain it, otherwise you will have a diluge of antifreeze when you remove the waterpump. (If you do not drain the radiator, it will drain down to the point level with the lowest opening in the block when you remove the water pump anyway. It's just neater to get the antifreeze in a bucket as opposed to having it spash all over the garage floor. Even then - you will still have a little hit the floor...) Also - I'm not opposed to any shortcuts, it's just that I'm a big guy and I needed as much room as possible to work. Now, I ordered my hoses as a set from IMPCO, a division of Performance Products, located in Van Nuys, California. My set for the Turbo was $94.45 (US). My catalog shows the price for your TD is the same, unless you have a California version - that set runs $210.89. You can order their catalog online at: [URL=http://www.************************]
I hope this helps... Let me know how it works out. - Raven

[This message has been edited by Raven (edited 09-28-2000).]

[unkl300d]

Well, this may seem elementary but I wonder if you can see the leak source from below while engine is running (assuming all safety precautions taken) with a flashliht locate the weep holes (visible at top + bottom).
The H20 pump change on my 79 300d
did not require radiator and shroud removal.
(no york type A/C unit).
Your set up may be more complicated.
I did see my leak from bottom weep hole
while in supine position .
Good Luck

------------------
1979 300D
133K miles
1989 300SE
1995 C280

[Alec]

Thanks for th input Raven...I always operate on the primise that if I am going to do it I am going to do it right the first time. I probably will go ahead and remove the radiator if only to look check its condition.

I looked at the weap hole on top and I see no leakage from there...there is no way for me to see the underside of the pump...frustration. If I get it out and the seals are bad thne I'll replace them or the pump.

Alec.