Water pump question (OM617)
 

I am in the midst of replacing my water pump. I cannot seem to get at the bottom-most bolt. This is the one in back of the crank pulley - not enough clearance to get a socket in, yet the water pump housing has sort of a ridge in it, so can't get a good grip with a box wrench or pliers. How do you get at it?? I thought about removing the alternator but I don't think it would help.

Back story: went to go check out a 300SD from fellow forum member and ironically my water pump decided to fail then and there, about 90 minutes from home. Limped it home using a lot of water. It did hit 100* once on the trip back, but it seems to be okay still, don't see any milkiness in oil. This all stemmed (I think) from my radiator cap not venting. I came out one day to a coolant leak and when I opened up the expansion cap, FOOOOSH tons of pressure, surely beyond the spec 14 psi and that was after sitting all night. It eventually blew out the little radiator hose from water pump to t-stat housing, and blew the seal on my water pump which I am replacing now.

P.S. Many thanks to Rick for helping me with jugs of water to limp home!

Well at least you got a good flush!:D

First I'll state that I do not have a 617, but a 616 I believe they are very simular, and by looking at pictures of parts on fastlane I believe I'm right on this in this area . . .

So it looks like you need to remove the fan, and the pully should come off with that . . . (I assume you know that) You then only need to pull the water pump (the bolts on mine do not go outside of the range of the waterpump pully) which looks like this:
http://i153.photobucket.com/albums/s.../Waterpump.jpg

You should not need to remove, and hopefully not replace ($$$$$$247.50) the water pump housing (Which is what I'm thinking you are trying to remove the bolts to) Looks like this:
http://i153.photobucket.com/albums/s...umphousing.jpg

The bypass hose I just replaced is a dealer item . . . cost me $13.20 + tax & shipping! I just bought one for mine!

Edit to add: Phil only stocks it like MB sells it . . . 1 meter legnth! $135 IIRC here is a DIY Link http://www.peachparts.com/shopforum/showthread.php?t=262523

Unfortunately I am replacing the housing, and it is the bottom bolt off that which is giving me the trouble. I've got the fan and the shroud and all that off already, pulley is off, etc.

OK, that's different . . .

On mine (note: 616) I have about 1.5" clearance in front of it . . . doesn't do you any good though, It does look like on mine that the alt removal would give you some room to come in from the side . . . but I'd maybe cut down a socket to the shortened length . . .

Edit to add:

How about one of these:
http://i153.photobucket.com/albums/s...nz/Misc005.jpg

luckily I have a spare housing with pump (thanks again Rick!!) so the money for it isn't a problem. I don't think the u-joint sockets will fit...Maybe I'll try bending up a box wrench to fit it perfectly? I don't know a bit stumped here...I'm leaning more towards taking the alt bracket off but don't want to create too much extra work for myself. This is my daily driver so tthe quicker I get it on the raod the better.

You can rotate the engine around to get to a cut out on the balancer to access that bolt.

Unfortunately already done that...gives a little bit of room but still not enough, maybe about 1/2"

Okay, I was able to remove the pump anyway, didn't try the housing.

The notch should allow good access to the lower bolt. If the notch in the balancer isn't enough the only other option is to take the balancer off. Mark it's orientation and pull the six allen sockets out and your good to go. I had to do this on a 115. It's really not a big deal.

With the pump off, is there not now room from the top?

There has to be a way . . . most everything else is pretty straight forward it seems to me.

^ Maybe so, I didn't check at the time and it was a while ago. I'll suggest using anti-seize compound on the bolts as I broke one off while attempting to swap out the pump. That was the straw that broke that camels back, went to the crusher shortly thereafter.

Wondering around the tool section at Sears, I brought a few neat toys home. They make getting into tight places easier.
About 1 and a 16th inch deep.
Two different tool sets there.

That socket/ratchet would probably work perfectly! I'm going to wrestle with the bolt some more this afternoon. In the middle of the night last night I realized that when trying to undo the bolt I had coolant running over it...meaning the housing probably isn't leaking but rather the water pump itself out of the very bottom. I'm keeping my fingers crossed, since it might make my job a lot easier. I was going to swap out the whole housing since I have one sitting in my trunk waiting to be put in but I might be able to replace and reseal it. Guess I'll post here after I get the gunk off my hands tonight to update.

Well good news, after wrestling with the thing for a good 2 hours, I pried the water pump propeller off (totally stuck on by the way...) and managed to get the bolt out with vice grips. Not sure where it was leaking, but there was no gasket in between the block and water pump housing. I imagine there should be one there...I will probably end up RTVing it on the install.

Some lessons learned....

Make sure you note which bolts go where. One bolt (the lowest one behind the crank) is shorter than the rest. I wasn't paying attention and put one of the other "normal" sized bolts into that hole...got about 3/4 the way there and couldn't figure out why it wouldn't go in more. Being an idiot, I just took the vice grips and screwed it in as far as I could...got it in tightened. As soon as I realized I had a shorter screw, I uncrewed that bolt. All the threads on the end were stripped but I have no idea where the screw actually went. I hope it didn't go into the timing mechanism or crack/stress the block. I'm really worried. Putting the pulley and fan and all that back on today, keeping my fingers crossed that it will run.