Tony, you don't say what engine you've got. My own experience is with a Volvo D1-20 in a Bav 30, and I'm sure it would be equally applicable to slightly bigger Volvos in slightly bigger Bavs.
I had a fairly bad leak from the back of the raw water pump at about 250 hours. I thought that was a pretty short life, though I'm based in the Bristol Channel so the poor old thing spends much of it's life pumping liquid mud.
First off, the pump was a swine to get off. I removed the vertical board at the front of the engine bay to get slightly better access. Then I had to work back-to-front on four unseen bolt-heads or nuts (I forget which) to remove the pump from the engine. The seals were absolutely shot and there was a groove worn in the shaft. I forget about the bearing so maybe that was OK, or maybe I replaced that too. I had a local mechanic do the disassembly and reassembly.
Sourcing the seals (and perhaps bearing) were dead easy. I used my local bearing specialist on the nearby industrial estate. It happened to be Hayleys (
www.hayley-group.co.uk) but it could have been anyone. Seal sizes are standardised so you just need to read the number off the old seal and ask for that. Do make sure that they have stainless steel springs because I believe some seals are also available with carbon-steel springs, which are happy enough to live in oil but not so keen on salt water.
I thought about a number of solutions for the shaft:
- Buy a new shaft. This was definitely the non-preferred option as the cost was £287 if I remember correctly.
- Have a new shaft made. Although the shaft is simple enough, it would still be fairly expensive as a one-off.
- Put a packing washer behind the seals so they run on a different part of the shaft. Potentially this was the simplest and cheapest solution but Iwasn't totally convinced that it all stood up dimensionally. It seemed a bit of a bodge, so I put the idea to one side.
- Grind the shaft undersize to clean up the wear area. Having measured the groove and checked the data sheet for the seals, this would have put the shaft diameter at the absolute minimum that the seal would tolerate. It seemed to be pushing my luck a bit.
- Fit a press-on sleeve (Speedi-sleeve made by SKF). The smallest available Speedi-sleeve was the right size for the job. Made by SKF who should know what they're doing. It makes the shaft diameter bigger, but still within the spec for the seal.
I opted for number 5. It has worked well for the last year and a half, although I still expect the seals to fail again fairly early as they are running on a small diameter. The seals were a couple of quid each and the Speedi-sleeve was £25. Then there was about an hour of labour for the mechanic to do his bit. Altogether much cheaper than feeding the Volvo greed machine.
