Shortcut Water Pump Replacement Tips? - Page 2 - PeachParts Mercedes-Benz Forum

long-gone · #16 03-05-2011, 02:56 AM

A trick I use on the UTC seal is to use a thin piece of plastic between the cover and the top of the gasket, as described:

*THOROUGHLY clean the surface areas where the gasket will set and meet the cover.

*Clean metal surfaces with alcohol, thinner or similar solvent so they are completely dry, clean, and free of any lubricants.

*Prepare a small rectangular piece of plastic that will be placed between the fitted upper cover and the gasket. The piece should be slightly wider than the width if the timing cover and about an inch or so deeper as well. The plastic should be stiff and as thin as possible but strong enough not to break or stretch when pulled out (being pinched under the cover). You'll find that you'll need to cut a wide "U" shaped notch in the front of the plastic to accommodate the timing chain. The plastic won't need to extend all the way to front edge of the head, within about a 1/4" should be good.

*before laying the gasket in place, using only the recommended MB black sealant, apply a liberal (but not excessive) bead to the corners where the lower cover meets the head. Set the gasket in place and apply another bead of sealant on top of the gasket at the same corner against the head where it will meet the upper cover. Apply it in those places ONLY, taking care not to let any fall into the lower timing area. It is recommended that you probably shouldn't use any on the other gasket surfaces, just in the corners as described.

*You'll need to proceed without much delay as the sealant starts to set fairly fast.

*Lay the prepared piece of plastic on top of the gasket. Remember, it doesn't need to go all the way to the head (and so it won't be in contact with the bead of sealant, but it probably won't hurt anything if it is).

*Now, when you slide the upper cover into place, it won't roll, catch on or otherwise move the gasket and it should slide in place somewhat easily. Insert the cover bolts a few threads but do not yet tighten them. While holding pressure on the cover with one hand, pull the plastic out.
Quickly or slowly and carefully? Not sure if one way is better, but you might want to try a dry run (without the sealant) first and see what works/feels best.
If you think a lubricant is needed, I would probably just use a light coat of water or spit, which will dry quickly and repel oil until it does.

Well, that's it, the big "trick"! Not much but it made the ones I've done trouble free, and neither has sprouted a leak yet (over a year). Hope it helps.

Ferdman · #17 03-05-2011, 06:58 AM

Steve, follow long-gone's instructions for installing the upper timing chain cover gasket. That method works. Recommend buying a new U-shaped gasket because the first one is likely trashed due to the RTV sealant coating.

sptt · #18 03-05-2011, 09:24 AM

Yes Ferdman! Thanks again! That is a very good tip. As you have to apply downard pressure and slide that cover on but it does pull on and roll that gasket. Live and learn! Thought that would be easiest part of the job yesterday. But thanks again, I'm sure that will work. Until then, carrying oil with me.
One tip that worked for me on getting the water pump out was to use to different length 13mm box wrenches on the top rear bolt just to crack it (after moving dipstick out of the way). Once I did that, it was much easier to wratchet out at that awkward angle. The bottom rear came straight out and went straight back in. I also did not loosen the waterpump mounts just took off the pulley. Pump came out and went back in. Tensioner went out and in and also adjusted very easily.

Steve

Ferdman · #19 03-05-2011, 06:35 PM

Steve, I take it you meant to say "power steering pump mounts" instead of "water pump mounts".

sptt · #20 03-05-2011, 11:37 PM

Woops. Yes....power steering pump mounts!

sptt · #21 03-07-2011, 12:54 AM

Wow....that was the trick! Much easier to do with the plastic film in there while putting cover back in. Cool trick. Only problem is I need the car tomorrow and I while in there today I noticed I damaged the cover seal where the rotor mount comes through when putting cover back on. So I had to put it back together all nicely sealed on the bottom but with oil leaks now potentially coming through the shaft seal. No big deal because it only takes about an hour to do. Thanks so much for the help...again!

EricSilver · #22 03-15-2011, 06:07 PM

Quote:

Originally Posted by long-gone

*Lay the prepared piece of plastic on top of the gasket.. ....when you slide

Am I correct in assuming that if I do this I will not need to bother with pulling that threaded pin?

sptt · #23 03-15-2011, 06:35 PM

What threaded pin are you referring to?

EricSilver · #24 03-15-2011, 07:07 PM

Quote:

Originally Posted by sptt

What threaded pin are you referring to?

The one that supposedly gets in the way when replacing the cover -- because it requires you to slide the cover forward and, inevitably, roll the gasket.

sptt · #25 03-15-2011, 07:40 PM

There is no threaded pin that gets in the way. Not sure what you are talking about there. What challenged me was that the u-shaped gasket sticks up (has a ridge) and you have to be able to press the cover down on top of it while pushing it in and pushing it forward to get over the camshaft without rolling the gasket or damaging the camshaft seal at the same time.

EricSilver · #26 03-15-2011, 08:21 PM

I believe it is the guide rail retaining pin.

sptt · #27 03-15-2011, 11:40 PM

That part does not come into play on this repair.

EricSilver · #28 03-15-2011, 11:45 PM

Would you be inclined to post some bullet points of what you did?

I can already envision the fan, fan shroud, crossover pipe and bypass hose removal. But what else? And is it necessary to remove the valve cover as well?

EricSilver · #29 03-15-2011, 11:48 PM

Wait -- scratch that. We have different engines so the processes would differ.

On the M104 the guide rail retaining pin is an issue, but the aforesaid plastic shield option sounds like a workaround.

long-gone · #30 03-16-2011, 12:51 AM

I'm a little confused as well. On an M103 the guide rail pin only needs to come out if you're pulling the head. But, you're talking about an M104, which I'm completely unfamiliar with.
The piece of plastic merely gives the cover something smooth and rigid to slide on while being pushed down. I'm pretty sure it wouldn't matter what kind of engine it is, but whether it helps with that pin issue, I have no idea.

While I'm thinking of it, assuming a pin is in the way, and you remove it to facilitate putting the cover on, how do you put it back in once the cover is on?