Fridge cooling pump replacement

[MikeBz]

I recently discovered that the cooling pump on our seawater cooled Isotherm 5000 fridge is leaking, and has been for some time. I uninstalled it, removed the lid, and supplemented the oddly shaped double o-ring with a very light smear of sealant. Refitted it to the boat and ran it - it pumped water for a few seconds and then no more (pump was still running). So remove it again - and this time trying to pull the pipe off the barbed outlet spigot the spigot snapped off flush - so I think it’s time for a new pump.

I’ve had no luck identifying the pump, and can’t make out the only lettering on it:





It’s at least 30 years old, I suspect long obsolete but if anyone can identify it it might help.

This looks like a suitable replacement:

SELF PRIMING PUMP FOR FRIGOMATIC FRIDGES AND FREEZERS (24V pump must be run at 12V ) - Penguin Refrigeration

… except that the barbed inlet/outlet are 1/2” OD, and the inlet/outlet on the old pump (along with the metal pipes on the compressor unit itself) are 4mm OD. Nobody seems to make a 1/2” (or even 13mm) to 4mm reducer. Could be bodged with sequential reducers perhaps but a bit horrible.

 

[PaulRainbow]

Worth having a word with Paul from Haven refrigeration ?

 

[vyv_cox]

My custom water cooled fridge uses a Par Max1 pump running on 6 volts via an Isotherm voltage reducer. 1/2 inch inlet and outlet. The pumps last about 10 years with a lot of use but eventually the plastic parts of the swash plate mechanism wear out.

 

[Stuart Campbell]

I’ve replaced the pump on my fridge recently when the last one failed just before a trip, I used a water pump off of an Eberspacher wet diesel heater I had kicking around, my pump is located below the waterline so it did not need a self priming pump.