w115 water pump mount etc - Scoop? - PeachParts Mercedes-Benz Forum

Topher39 · #1 05-13-2013, 01:07 PM

What is the scoop with the Water Pump and cooling pipe mounting. I have changed plenty of water pumps, but never on a MB w115. Tell me about the large, threaded sleeves with a bolt that appears to run through? Not sure what I am looking at, or how they work. I believe I have a leak from behind the water distribution housing, and I would like to have better access to cleaning up the pipe ends that the hose attaches to. Will replace the pump and gaskets.

Anything I should know about the process of removing the pump and the part behind the pump?

Shortsguy1 · #2 05-13-2013, 02:28 PM

Topher-
It is the same as more recent diesels, I believe. So you should poke around on the diesel forum a bit.

Attached is the page from the EPC for my w115 220d. I bet yours is similar. Behind the water pump is the water pump housing, which I believe attaches to the block. Separating them from each other can be a pain, depending on what type of gasket or adhesive the previous mechanic used.

I was trying to remove a water pump from a w115 240D in the salvage yard last week, but I simply couldn't get them apart with the tools that I had with me.

Coastal220 · #3 05-13-2013, 04:58 PM

Quote:

Originally Posted by Topher39

What is the scoop with the Water Pump and cooling pipe mounting. I have changed plenty of water pumps, but never on a MB w115. Tell me about the large, threaded sleeves with a bolt that appears to run through? Not sure what I am looking at, or how they work. I believe I have a leak from behind the water distribution housing, and I would like to have better access to cleaning up the pipe ends that the hose attaches to. Will replace the pump and gaskets.

Anything I should know about the process of removing the pump and the part behind the pump?

I'm not sure what to make of those mangled studs but here is an image of the pump housing with pump removed.

Topher39 · #4 05-13-2013, 06:22 PM

I'm thinking that the threaded posts or standoffsthat the water pump bolts go through must be for mounting something? I have a gas motor, perhaps the water pump housing was pulled off another car.

Shortsguy1 · #5 05-13-2013, 08:13 PM

Looking at your photo and Coastal's suggests to me that the bolts holding the bottom of the housing have loosened on yours. He has two bolts at the bottom of the housing which appear tightened down. Your photo looks like it has the same bolts, but they are backed way out. Maybe I am totally misreading the pictures, but this is what I see. Perhaps that is where your leak is coming from.

Topher39 · #6 05-13-2013, 09:50 PM

No, these are some sort of threaded inserts or standoffs - there are smaller bolts that are within those inserts that seem to hold the entire assembly tight against the block. I will have to get into it over the weekend and take it apart to see what I am working with. Thanks for your input - I have just never seen anything like this before.

any other feedback is welcome and encouraged.

Topher39 · #7 05-13-2013, 10:24 PM

Update - Shorts, a beautiful evening in AZ, the car is cool enough to work on it a tad. You are partially right, the two lower bolts that hold the water pump housing to the block were loose! one, I could turn with my fingers! What I also found is that the threaded sleeves are being used as spacers/stand offs - why I have no idea. They don't thread into the housing at all, they are allowing really long bolts to hold the housing against the block - strange. I tightend the bolts up, will have to see if that stops the leak. I will plan to remove those spacers and use new bolts when time allows, and check the condition of the waterpump.

Thanks Shortsguy for suggesting tightening them - would be nice if I had something simple for a change.

Chris

Shortsguy1 · #8 05-14-2013, 12:19 AM

Glad I could help. I am always reading yours and Coastal's threads, but I know so little about the cars that I can rarely contribute.

So I have been thinking more about why someone would do what you found. I have two theories.
1) They simply didn't have access to bolts of the correct length, so they used the standoffs to maintain pressure with incorrectly sized bolts.
2) The lower pin of the timing chain tensioner rail is down there somewhere. And to pull that pin, you have to create some sort of puller. I wonder if those standoffs were used as part of this puller. See post 31 of this thread:
9 degrees of chain stretch

I am having trouble matching everything up between your photos and the photos in that chain stretch thread, but it was just an idea I wanted to mention.