A2T

Replacing leaking water pump on my 87 300D (124). Newbie here, please help!!

Ive printed out the manuals online, but if anyone has done this on a 124 300D Id really appreciate some input.

Got the rad out last night, now Im looking at the fan – how do I remove it? Just back off the center bolt? Its not left hand threaded or anything is it? How to hold fan while Im loosening? Also, does fan need to be separated from viscous coupling, or can it all just come out together by removing the center bolt?

How to remove poly belt? Manual says to just remove that top bolt and nut from tensioner spring, then what? It just comes off…?

I obviously do not have the “counterholder” to hold the wp pulley, but can I just put a wrench on one of the nuts holding pulley onto wp?

The manual also says to remove both halves of the wp, which means removing the alternator. Is this all necessary, or can I just remove the front half of wp?

Any and all help here is much appreciated. I know the manuals are good, but for a newbie, 1st hand experience doing the job is even more valuable! Teach me and I’ll teach others!!

Paul
www.GruvenParts.com

generalbeany

I know this is an old post, but here's some info for people searching 1987 300D / 300TD repairs:


This thread will answer many of your questions (Pulling the radiator isn't required for fan/fan clutch replacement, and I am about to attempt a water pump replacement also without removing the radiator...):

http://www.peachparts.com/shopforum/...placement.html

-I was able to remove my fan without using the serpentine belt stopper tool, but I hear that goes either way. (Details/picture of tool found in above link)

-the fan/fanclutch center bolt is normal thread, lefty-loosey

-I just talked to a diesel tech at the Hoehn Mercedes service center in Carlsbad - he said all that's required for waterpump replacement is draining coolant, fan removal, and belt tensioner/belt removal (all the junk in the way of getting to the water pump bolts, [the bolt heads face the front of the car]). Anyone have differing experience?

Thanks,
Daniel

PelicanParts.com

The DIY thread is correct.
I strongly suggest getting the http://www.harborfreight.com/pulley-...ool-66385.html .
It makes the job easier.

roy@pelicanparts.com

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generalbeany

Thanks Rob- I seem to have no problem getting the fan blade off without the tool. Is that that only time it's useful?
Also, is there anything tricky to watch out for when draining and refilling coolant before/after I install the new water pump? I.e. to make sure air isn't trapped etc?
(1987 300TD)

Thanks again,
generalbeany

PelicanParts.com

There are few other times that tool has any use.

Disconnect the large upper hose from the radiator.
Fill the cooling system through the hose.
Do not stop filling until coolant runs out of the upper radiator hose fitting.


roy@pelicanparts.com


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jorotek

How in the world do you get that very bottom water pump bolt out?

generalbeany

Yeah that was was a PAIN to get out - I used my smallest open ended wrench to sort of get on it and was able to get it out... BUT THEN a week ago I replaced my fan belt tensioner and I noticed that when it was removed (along with the water pump pulley), those bottom water pump bolts were SUPER easy to get at. Definitely take off the tensioner and pulleys in the way. Job becomes 1000x easier and then you can get proper torque on those bolts instead of a halfass job like I did the first time.