Endless Pool hydraulic pump question.

[grunti39]

I have an indoor Endless Pool which I installed as part of a new home construction in 2003. We really enjoy the pool, but I have a question about the replacement of the hydraulic pump. The water tight seals deteriorate, therefore the pump must be replaced to prevent hydraulic oil from contaminating the water. I replaced the pump which cost several hundred dollars four years ago and now it is time to do it again. I worked with heavy equipment all my life and just about all hyd. pumps can be rebuilt. NOT SO according to Endless Pools, one must purchase a new one. It is a pump so somebody should be able to put new seals into it thus saving hundreds of dollars. Does anyone on this forum have any experience with the Endless Pools hydraulic pump?

[PoolDoc]

I did a fair amount of checking, before I tried to answer your question.

I think you are talking about the Endless Pool "hydraulic motor",

https://lh4.googleusercontent.com/-NmX1AgIFVTA/T0ZmDr_LooI/AAAAAAAABPo/U-7caWZROIg/s400/hydraulic-motor-replace-kit.JPG.jpg

which drives a 5HP capable propeller like this one:

https://lh4.googleusercontent.com/-RDbUzAXjLFw/T0ZmEwK6kOI/AAAAAAAABPw/16-WqqaMtnc/s400/black-propeller-5blade.JPG.jpg

Is that right?

If so, I'm not sure you want to bother with seals. The problem I see is that most hydraulic pumps are not really made to be submersible. Endless Pools own manuals suggest that the motor will die ever 5 years. What it looks like is that they've taken a standard carbon steel, electrolytically zinc-ed (not much zinc!), motor and partially potted it in epoxy. So, it's sort of a working kludge, but not really a submersible hydraulic motor!

The reason they've probably done this is that truly submersible pumps are almost certainly VERY expensive. I checked -- they do exist -- but they seem to be an industrial specialty item, and I couldn't find any pricing. But I did confirm that virtually all 'normal' hydraulic motors are cast iron, malleable iron, or carbon steel, like this one from Northern Tool:

https://lh5.googleusercontent.com/-IRL5qfn45Ds/T0ZmFX7RZbI/AAAAAAAABQA/3Wk8mUM2EH4/s800/motor%25201001_lg.jpg

a motor very similar to yours. It costs $275 as of Feb 2012 ( http://www.northerntool.com/shop/tools/product_200321041_200321041 ).

I think you are probably stuck. Endless Pools are luxury priced items with pretty high markup. And, with the big 5HP power unit, your costs of operation, electrically, is VERY high, if you use it much. Many of the components are pretty standard -- you can replace the water pump, filter, hydraulic power unit, etc with non-factory parts, if you know what you're doing. But, the 'submersible' hydraulic motor (not: pump) is actually a unit unique to Endless Pools.

If you want to explore rebuilding the motor, that's possible. But if you actually use the pool, I'd recommend going ahead and buying a new motor. Then, SAVE the old one, disassemble it, and visit some industrial hydraulics suppliers. If you get an old counter guy, with 30 years of hydraulic experience, he may take one look at it, and say something like, "Oh, that's a Dimwitchie Hydraulics model 33-JR9 unit, that they've modified some. Hm-mh. You can probably rebuild it with the Dimwitchie JR9-c3 rebuild kit -- it's $63.87." If that happens, you're in business.

Otherwise, plan to visit the Endless Pool parts site every 4 years!

[grunti39]

Ben,

Thanks for your quick reply! Yes, you are correct. It is the hydraulic motor and I do have the one that I took out 4 years ago. I'll start trying to find a hydraulic shop that may be able to rebuild this thing. From what I was told by EP, it doesn't matter how many hours the motor is used, but the years being under water that counts. If the seals fail, all that spilled oil would be a mess to clean up! Thanks for your help!

Jack