Leaking water pump

[Lanikai]

Hi everyone,
I am having water pump issues on my raw water cooled A4. We installed a new pump from MM shortly after buying the boat. After about 200 hours the pump started to leak out the hole in the bottom. At first there was some light, beige colored slime coming out the bottom. Then it was dripping water, and soon after, it became a real gusher.

At that point we rebuilt the old Oberdorfer pump (with rebuild kit from MM) and installed it. Same thing again, after about 210 hours (full-time cruising), the pump started to leak and the condition deteriorated quickly. This pump has a grease cup and we made sure it was always filled and tightened it a turn or so every once in a while.

Any ideas what's causing the problem, before I go and ruin another pump? I appreciate any insight.

[sastanley]

200 hours doesn't seem like a long enough time between rebuilds to me. I assume these are the Oberdorfer's with the two seals (202 series?)

At least you have two pumps and can always have one ready to go!

Sorry, I am not much help this morning....welcome to the group though!

[hanleyclifford]

Welcome to the forum. It sounds like you are chewing up seals on the water end of the shaft. This could be due to the nature of the water you float in or some alignment problem possibly even the accessory drive. Next time you take it off try making some lateral movement of the drive.

[Jesse Delanoy]

I've been through two MMI pumps on my MMI-rebuilt A4 in the past three and a half seasons (approx. 100 hours use per season). The first one developed a bad leak out of the back plate which I couldn't correct, and the second started leaking out of the weep hole. Through a miscommunication, I wound up with another new pump, which I have just installed. At Don's request, I have returned both old pumps to MMI, so they can inspect and hopefully determine what's been happening.

If I find anything out, I'll let everyone know.

[roadnsky]

I agree with Hanley...
Something going on with the shaft.
Likely the alignment between the Accessory Drive causing a slight "wobble"?
You might get very lucky and it's as simple as one of the 2 bolts that hold the drive could be loose?
Check them and try tightening them both. (See pic)

[sastanley]

holy cow!

Jerry,
Do you have a picture of every possible angle on the A-4 with the appropriate piece removed for clarity for every discussion possible???

Great work, dude!

[Jesse Delanoy]

Apparently MMI has gone to a slightly harder alloy in the manufacture of pump shafts, on the theory that the softer metal may be wearing inside the seals and becoming susceptible to leaks.

[roadnsky]

Jerry,
Do you have a picture of every possible angle on the A-4 with the appropriate piece removed for clarity for every discussion possible???

Great work, dude!

Uhh, no. Wish I did though.
I do take lots of pics/angles when I take something apart.
It helps me to understand things better.
Thanx though...

PS - LANIKAI, Welcome (Aloha!) Where in the islands are you? Kailua? Kaneohe?

[Kurt]

Ugh -- review my old posts in the archive as I had the same exact problem and it drove me and Don nuts! The solution was replacing the assessory drive. My water pumps would last actually less than 200 hours -- more like 30 hours or so towards the end of my search for a cure. Don and I talked, but he had never seen an assessory drive actually cause repeated water pump failures. The only indication that my assessory drive gave as to it being worn out was some noise, but nothing that seemed to get worse or anything. I bought a rebuilt drive from Moyer and the problem was largely solved. I did, however, end up having another water pump leak (different seal - water seal this time, not oil - oil seal is closest to the assessory drive) and I needed to get a new water MMI water pump shaft from Moyer. Don did say that they had some faulty pumps out there. So, you may have one or two things going on here. These are really the only things that I, after going through this issue, can imagine would cause this problem - as long as you are correctly rebuilding your pumps (I got pretty good at it - give me 15 minutes and I can get one done!). Cheers - check out my old posts for more information.

[hanleyclifford]

This is not a condition that occurs often, but Kurt has put his finger right on it. Take the pump off and check the bearings in the accessory drive. If the shaft is not being carried true by the drive, it can wobble and shorten the life of the seals.

[Lanikai]

good ideas

Thanks everyone for all the helpful advice. There are several things I need to check out now. I also heard from Don that the seal life is often dependent on water quality, and that they've recently changed the hardness of the shaft.
The first pump that failed spent its entire life on the ICW, but the second one spent its entire life in the bahamas, so I seriously doubt it's water quality that's the problem (unless it prefers dirty water).

Kurt, it's interesting what you said about the sound. I'd forgotten, but when it first started to leak I was hearing a faint ticking coming from the pump.
When I pulled it off today there was a bit of black grime/grease just inside the weep hole. I'll look into the accessory drive alignment.

Thanks again! Oh, and Roadnsky - unfortunately I'm not in the islands but in fort lauderdale.

[roadnsky]

Oh, and Roadnsky - unfortunately I'm not in the islands but in fort lauderdale.

Ahhh, you fooled me with the name.
(But it did get me thinking about home)

[Kurt]

Lanikai - just a not on the grime/grease you saw in the weep hole. I experienced this as well. If you have the MMI pump on there, these pumps have 2 bearings that fit onto the shaft. What I found is that when the water seal fails, the bearings tend to get water in them and freeze up (or become very difficult to move). They then fail and ooze their grease -- along with water and possibly crankcase oil if your oil seal has also failed. Plus, a wobbling shaft can cause these bearings to fail, but the shaft seals are much more likely to fail first. If you have the Oberdorfer pump on there, the grease from the grease cap can simply be mixing with crankcase and/or water, creating an interesting slime that bunches up at the weep hole. Trust me, I have see anything that can leak out of that thing!