Replacement cover for impeller pump

[TonyS]

I used to have your problem. Sometimes the impeller only lasted 2 months. The cause is the pump running dry. If it is wet all the time the impeller will last years.
There is virtually no water lost when you remove the 1" hose from the entrance to the heat exchanger. It has drained out into the exhaust when you stop the engine. You will find the bits there which can easily be felt with your finger and removed with long nosed pliers or they will be stuck in the outlet of the pump. The way to keep water in the pump is to fit a non return valve just after the pump. It costs less that £10. I last replaced an impeller 5 years ago and examine periodically as I have also fitted a speed seal. My engine has done more than 1400 hrs. A second benefit is that your water seal behind the pump will also last for ever, so you won't need a new pump. I discussed the NRV with Volvo at SIBS. They said don't tell anyone as it will cost Volvo a fortune in spares!

 

[nigelmercier]

The way to keep water in the pump is to fit a non return valve just after the pump...

Just before the pump, surely?

 

[bajo]

Speedseal kit best money spent .I had the pump on my 1GM10 Sucking a wee bit of air which brought on the temperature waring,thought it was an impeller problem, inspected ,and was in no way able to replace or rectify suspected gasket, pump impeller perfect just only had to reached for the speedseal kit and in a few minuets I was on my way .

 

[Tomahawk]

On a slightly differnt tack

When I lost my impellor cover... (please don't ask how) I had to find a replacement or buy a new raw water pump..

Looking carefully at it the other one (cat with two engines) I found that it is a Johnson pump made for Yanmar.. I did a lot of searching on the web and found their UK agents are in Dunstable. Whilst they could not supply some parts as those are OEM designes, they coould supply new cover. Later lehen I found that the seal was going home, they also supplied a replacement shaft, very inexpensive, Somnew seals and bearings and the pump was good as new..