Oberdorfer 202m-908

[cuthbert]

I have the oberdorfer retrofit and was looking at the pump and had a few questions/comments

1) The lower barb is approx 3mm from the alternator belt, no side play. no markings, so its all good, but how close is too close. I would post a photo but don't have one ...this pic is one the C34 site and gives an idea of the fit

13_M35b_mount_-hoses_1.jpg (45.55 KiB) Viewed 1943 times

2) The bronze/zinc body material is slightly green at the back top surface implying a weeping from the weep hole. early indicator of a need to dive in and change O rings? Is any weepage acceptable?

[russp]

My experience is “no” weeping is acceptable as it drips down to main crank pulley wheel which corrodes on the face, then chews your belt up.

[cuthbert]

Just following up on this I spoke with Depco in Florida and ruminated on it for a year or two, but after reading a story in Mainsheet of a 15 year old impeller failure it spurred me to act. Bottom line is as Depco and Russ above points out no water is acceptable in the long run. For the water to exit the weephole albeit in small amounts means that the front lip seal has started to leak. If the rear lipseal was to leak then it would be oil that would be staining the pump body and if both seals leaked then water could get to the oil and that could be very bad. But it was time fix the pump and change the belt. Removing/Installing the pump is easy (two x 10mm bolts needing a small ratcheting ring wrench to reach in). Then rebuilding the pump was done with an arbor press to push the old seals out (there is an oberdorfer 202 video on you tube where they are hammered out). I used the catalina direct kit which is a bit weird in that it includes new washers and faceplate O ring but not the carbon bushing or the gasket between pump body and engine. Pressed the old seals and carbon bushing out and cleaned and checked everything, no wear or markings on the shaft or bushing so all good there, the old impeller was 3 years old and had no wear that could be seen, but changed it. Then put the old bushing back in with two new lipseals, polished faceplate inner, installed the O ring and reused the gasket between pump and engine with a thin bead of gasket goo. Also tweaked the adapter elbow about 10 degrees more as the clearance from elbow/hose to belt always seemed a bit close for comfort. I used a hose clamp that can be released by hand in case the belt was to break and it needed a quick change. Here are the before and after pics, you can see the amount of belt stretch on the original westerbeke marked belt vs Gates XL replacement by the alternator position.

[Captain Kirk]

Great information, I like the idea of tweaking the elbow for a little more room.

I just had my Oberdorfer replaced after having had new lip seals put in last year, with the water leak recurring after just 50 hours. My diesel tech suggested to go new considering 19 years and 2400 hours the old one had served.

He also gave me a good tip on how to store your spare belt. I don't have a pic but here's how to do it.

If/When you have the raw water hose removed, loop the spare belt over the hose and just slide it down along side the engine to store it and keep it clear. Reconnect the raw water. The spare belt is now behind the hose can be put on without having to remove the hose. Its a bit of a timer saver and great if it needs replacing while at sea.

[KenKrawford]

Pretty slick idea on storing the spare belt. The only downside I see is the belt being subjected to the higher heat of the engine compartment.