Note that you may also have an O ring or 2 on the shaft that the impeller turns on that are on the engine side of the impeller. On my Beta, there were 2 O rings between the impeller and the engine--these keep the water out of the crankcase, etc. If these are bad or the shaft is 'scored', replacing impellers, or O rings on the non-engine/impeller side of the shaft will not solve your problem. In my case the shaft was 'scored' and I needed to replace the entire pump assembly since the Beta shop could not reasonably remove the scoring.
Charlie Nelson Water Phantom C&C 36 XL/kcb Oriental, NC [email protected] -----Original Message----- From: Neil Gallagher via CnC-List <[email protected]> To: cnc-list <[email protected]> Cc: Neil Gallagher <[email protected]> Sent: Wed, Jun 7, 2017 10:18 am Subject: Re: Stus-List Yanmar 3JH2E leak around water pump impeller cover Bruce, The issue with putting a gasket under the cover is that now the cover will be moved away from the edge of the vanes of the impeller. The pump works by creating a vacuum in each space between the vanes at the inlet as the impeller vanes open up and pressure when the vanes close down a the outlet. The vanes need to contact the cover to create a seal, that's why an o-ring is used, it keeps the cover in contact with the edge of the vanes. Bottom line, the gasket would have to be very thin not to affect the pump's performance. On some pumps you can buy a new cover as well as the gasket because the cover wears, I'm not sure about the Yanmar. Neil Gallagher Weatherly, 35-1 Glen Cove, NY On 6/7/2017 8:51 AM, Bruce Whitmore via CnC-List wrote: Hello, I replaced the impeller on a Yanmar 3JH2E about a month ago, and I was checking over the engine last weekend and noticed some wetness coming through around the impeller cover. I tightened the cover bolts (they were not really loose), and the leak still continues. When I replaced the impeller, I also replaced the o-ring, so that should not be the issue. That said, the old o-ring had a tear (the cover was leaking, though more so then). The face of the water pump was also a little rough, presumably from people prying with angled needle nose pliers in the process of removing the old impeller. That said, the cover itself was smooth, and the groove for the o-ring was fine as well. I personally don't like the idea of relying on Yanmar's very thin o-ring for sealing something that is below the water line. I am thinking about getting some thin cork gasket material, and cutting a proper gasket, applying teflon grease to it, and using a gasket instead. Is this a bad idea? By the way, our boat is a 1994 C&C 37/40+, and the way the engine is mounted in the boat, it is nearly impossible to get to the bolts to remove the water pump, and even removing the starter is not exactly a fun job, again due to poor access to mounting bolts. Thanks for your insights! Bruce Whitmore (847) 404-5092 (mobile) [email protected] _______________________________________________ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated! _______________________________________________ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
_______________________________________________ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
