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

sptt · #1 03-02-2011, 01:24 AM

OK guys...I have read and seen all the great water pump replacement threads and pics (and they really will help!). Just wondering if anyone has some good tips for getting those pulleys off and stuff removed with my basic laymen's tools. One good tip I received was to put electrical tape around the elbow joint of the 13mm socket to get it onto the lower back bolt of the pump so it still flexes but is stiff enough to guide in and on to the bolt head (craftey old mechanic!). I have the tool for the fan clutch so that should be easy. Any other good ones out there? I have a new pump on the way as my pump bearing is going bad after 195K (wow!). '91 300E.

Thanks!!!

Ferdman · #2 03-02-2011, 06:01 AM

sptt, loosen the power steering pump pulley bolts before removing the drive belt.

Be prepared to replace the drive belt tensioner. It would also be a good idea to replace the drive belt and thermostat.

lee polowczuk · #3 03-02-2011, 07:27 AM

you've got the tips..... make sure you drain the engine block of coolant as well

Fast. Cheap. Right. Pick two.... this job takes 5 to 5.5 hours.... no way around that.

i have done two.... the electrical tape is crucial

sptt · #4 03-02-2011, 11:54 PM

Thanks guys! Good stuff. I have already done my daughter's water pump but it was with someone who had an air wrench which made it faster. We did it in 3 1/2 hours but I will probably have to do this one on my own with hand tools. And yes, we did have to go back in and replace the tensioner afterwards (pricey part)! We did not loosen the power steering pump bolts first. I will do that this time. Any easier ways to get the pulleys off and not have them spin on the last bolt (this is where the air wrench worked easily)? Other than that, I have the flush kit installed already, new thermostat, cover, short bypass hose (special size fit), and O-rings ready to go. Would this also be a better time to replace the timing chain cover gasket and seal? I ordered those as well.

Ferdman · #5 03-03-2011, 05:44 AM

sptt, loosen the pulley bolts before detensioning the drive belt as the drive belt will prevent the pulleys from turning.

Good time to replace the upper timing chain cover U-shaped gasket. Recommend using a dab of MB black sealant at each end of the gasket only.

sptt · #6 03-03-2011, 09:57 AM

Ferdman....see, I knew there was another good tip still there! I have my new serpentine belt ready as well. Is the timing chain cover seal the one that typically leaks pretty bad on the passenger side? Also, what do you reccomend to use as a sealant when installing the new pump and o ring?

Thanks,

Steve

EricSilver · #7 03-03-2011, 10:17 AM

Quote:

Originally Posted by sptt

Also, what do you reccomend to use as a sealant when installing the new pump and o ring?

Nothing. The compressed O-ring itself forms the seal.

I am doing mine this weekend.

Ferdman · #8 03-03-2011, 02:34 PM

Steve, the upper timing chain cover leaks oil down the front of the engine.

As Eric mentions there is no need for sealant when installing the new water pump. The O-ring provides an adequate seal. Just make sure the O-ring remains in place before tightening the water pump bolts.

sptt · #9 03-04-2011, 01:40 AM

Ferdman, The leak is coming from the passenger side on the front right side of the engine nearest the fan and radiator (almost straight up from the alternator). It looks like it is the gasket underneath the bottom of the timing chain cover but I'm not 100%. It is not coming out of the manifold cover above it. There is this little rectangular piece of metal that sticks out of the head that is always wet with oil and it leaks from there.

Thanks,

Steve

JohnM. · #10 03-04-2011, 05:06 AM

Quote:

Originally Posted by sptt

Ferdman, The leak is coming from the passenger side on the front right side of the engine nearest the fan and radiator (almost straight up from the alternator). It looks like it is the gasket underneath the bottom of the timing chain cover but I'm not 100%. It is not coming out of the manifold cover above it. There is this little rectangular piece of metal that sticks out of the head that is always wet with oil and it leaks from there.

Thanks,

Steve

There is a stupid little double lipped rubber seal at the front timing cover. It's easily replaceable if your in there. Very common leak of sometimes "a lot" of oil on these cars. Just have to check, check and re-check that its seated properly while your seating/tightening the cover or it WILL leak.

I used a very very tiny amount of moly grease on the o-ring between the water pump and block to give it a little stickyness while not compromising anything. Its very hard to keep that o-ring seated while positioning the pump into place.

EricSilver · #11 03-04-2011, 10:50 AM

Quote:

Originally Posted by sptt

Just wondering if anyone has some good tips for getting those pulleys off and stuff removed with my basic laymen's tools.
Thanks!!!

See my post: M104/95E320 Water Pump Dry Run

Planning and Preparation will be the difference between a manageable job and a nightmarish one.

sptt · #12 03-04-2011, 11:05 PM

Well, I was able to replace the waterpump today with all of your tips!!! And John M, you are right, I could not keep that stupid little O-Ring in the water pump while getting it positioned. So, I put a couple small dabs of grease as well! It worked. Also, I replaced the Timing Cover Gasket and it is not leaking from the spot it was but is now POURING out of another spot...ughhh!!! I even put the dabs of MB grease at the tips after cleaning out all of the old gasket and RTV sealant someone else had used. Do you guys think I installed it wrong or does it have to work in and seal itself. The waterpump, new belt, tensioner, seem just fine. Good news, is, I just have to remove plug wires and timing cover to get at it. Not as big of deal as I expected but a pain.

JohnM. · #13 03-04-2011, 11:31 PM

Front cover should be sealed from first start, it won't seal itself if leaking now. The seal only goes one way, I remember having to use a liberal coating of black RTV on each side of the rubber gasket. The big problem is that the seal is easily "pinched" when reinstalling/tightening that front cover.... which will cause a massive leak like you described. Front cover leaks tend to get blown by the fan across the front of the engine so oil is probably everywhere now, lol.

sptt · #14 03-05-2011, 01:30 AM

John, I just retook off the cover and coated the heck out of it with RTV silicone everywhere I could see. Put it all back together, took it apart, checked the gasket, put it on, took it off, then felt great about the set and tightened it up. Turned on car and it started leaking front left right underneath the bottom left bolt in 20 seconds!

Tomorrow I will get some more RTV, dry the area all up, and force the heck out of it into that area and let it dry. The good news, is that waterpump works beautifully

and that was the hardest part of the whole job! LOL!

JohnM. · #15 03-05-2011, 02:16 AM

You don't want to use too much RTV, and it takes a few hours to properly set up. I'd say clean the channel that the seal sits in REALLY well and make sure theres no extra RTV in there. Just "coat" the rubber seal with RTV and set it in there, don't add any extra other than what wants to stick to the seal. Assemble and let setup for a few hours before starting.