Quandary
Well-Known Member
I took the impeller out of the raw water pump after lift out and planned to fit a replacement at the weekend. I had two in my on board engine spares box, a VP one in a typical blue box complete with sachet of glycerine and another in a plain white box labelled VOLVO 3593659 (the correct part. no. and applicable to quite a number of VP engines) Both impellers were purchased from the same large specialist mail order engine spares supplier. I decided to fit the aftermarket one, it differs from the VP version in that the drive pin is loose and has to be screwed in to place, the pin is completely threaded with a pointed leading end, but this is still tricky and involves enlarging the tiny holes in the rubber. I dipped the rubber vanes in some glycerine, checked the alignment of the slot and tried to slide it in to place. Would not go, so I put a cable tie round the vanes and tried again, I could only get it in part way, tried tapping it with a bit of wood and it was jammed. I took the pump out, as in place on the engine, it is difficult to work on (through a small aperture in the engine box).
I discovered that the drive pin of the impeller was too thick to go in to the slot in the shaft, not by much, probably be fine if the threads were carefully removed from the middle bit of the pin. I fitted the VP version no problem, the pin is already in place on those and the centre part which slides down into the slot on the drive shaft is plain not threaded. I emailed the vendor on Sunday suggesting a recall on these parts but so far have not had a reply.
Most people like to carry a spare impeller as they can fail unexpectedly but if yours is one of the aftermarket versions you could be in trouble if it failed at sea, what is usually a 15min. job could take all day, if you could finish it at all.
I discovered that the drive pin of the impeller was too thick to go in to the slot in the shaft, not by much, probably be fine if the threads were carefully removed from the middle bit of the pin. I fitted the VP version no problem, the pin is already in place on those and the centre part which slides down into the slot on the drive shaft is plain not threaded. I emailed the vendor on Sunday suggesting a recall on these parts but so far have not had a reply.
Most people like to carry a spare impeller as they can fail unexpectedly but if yours is one of the aftermarket versions you could be in trouble if it failed at sea, what is usually a 15min. job could take all day, if you could finish it at all.
