Beta 25 raw water pump Johnson overhaul, guidance appreciated

[FairweatherDave]

My water pump has sprung a leak (and it is not the plate hiding the impellor). This is new territory for me. Mine would be the 6 bolt Johnson version. It seems you need to replace the seals and maybe the shaft rather than just bolting on a new unit. The only helpful stuff I have found on the net is here (Vyv's stuff) https://coxengineering.sharepoint.com/Pages/Waterpump.aspx and it looks to me like I need to remove the pump and bring it home to do the work. Or is there a kit with all these parts and I can do the job aboard? I do my own servicing but I'm not a pro mechanic. Is the job straightforward. Guidance would be much appreciated before I start phoning Beta or ASAP.

 

[macd]

Yes, there are kits. Beta sells them for most of the pumps they use, but they're cheaper elsewhere. You might start with ASAP. This would be pukka kit, or very close to it.

Unless it's old or been running damaged for some time, the shaft should be OK. In that case, you'd just need seals and bearings: cheaper by far from bearing stockists. However, and it's a big caveat, the seals must be able to tolerate salt water. This means in effect that the spring inside the seal must be stainless. Most aren't, so check this very specifically with the supplier.

Much easier to do the job on a workbench, but certainly do-able aboard. Check You Tube for vids of the process on pumps similar to yours.

 

[Mrnotming]

Yes bring it home to the bench,I had a look at Vyv's share point site and his explanations cover all you need to know as regards a feasible rebuild,especially as he covers shaft wear and faceplate reversal,possible on some Johnson and Jabsco pumps.If the shaft is not scored,you can carefully note the numbers on the old seals and bearings.If not possible use a vernier measuring device to acccurately get the physical dimensions of seals and bearings.I got all new seals and spring tensioning rings ( specify what liquids have to be separated by the seals,I.e. Oil to air on the engine side ,salt water to air on the outer seal)I used Abbey seals Dublin www.abbeyseals.ie who supplied the seals by return post after a very satisfactory phone call.Take your time,replace or face grind/reverse any scored cover plate and the result should be as good as new or almost.There might be a possibility of a bodge where the seal position could be altered a little to encounter a fresh place on the shaft,depends on pump,not always possible.The bearings will be inexpensive from any good engineering supplier,and do buy the best ones for the job.An impeller can vary in quality too and needs its supplied lubricant liberally applied to prevent friction burn whilst being primed after installation.Good luck with rebuild.Fresh engine oil essential also.

 

[Jcorstorphine]

I have been mucking about boat engines for 60 years but these days I take pics of everything before I start work and during dismantling, eg take pic of impeller so you know which was the lobes bend. Look at which way the two seals are fitted i.e. the one nearest to the engine would be fitted with the spring towards the engine. The other one is the opposit way round and there should be a space between the seals over the weep hole. Take care you do not damage the lip of he seals when you push the shaft through. If the shaft has sharp splines, wind round a layer of sellotape to minimise.
Just take your time and it will be ok BUT if you get it wrong, a badly fitted seal could fill the sump with seawater which is not good. Happened to me when I bought a boat from a chap who had changed the seals on the engine a couple of weeks before he sold the boat to me. The guy had incorrectly fitted the seals with the water seal covering the weep hole and may have nicked the lip seal. Engine full of emulsified oil.

 

[FairweatherDave]

Thanks for all the replies, really useful. Point taken about checking the engine oil/changing it. Time is not on my side and nor is my level of expertise. I have found one you tube video and I am sure I could do the job. However I have gone for a new pump which is only a bit more expensive than new seals and a shaft from Beta ........ I really need to just bolt on a new pump on my swinging mooring and then get the boat to her winter home before daylight and insurance limitations kick in.

 

[Mrnotming]

Well at least you will be more informed about the dangers of neglected raw water impellor pumps,and others on here will find the link to the sites useful if in the same predicament. Cost me €18/£15 to overhaul mine as a bolt on spare.I also bought a new replacement for my Volvo 2030 due to cruising schedule commitments whilst boat was in the Med.good boating.Sorry McD our posts crossed,all good advice clearly delivered!

 

[macd]

I have gone for a new pump which is only a bit more expensive than new seals and a shaft from Beta

Which is another way of saying the price of the 'official' kit is ridiculous

Still, you're in a very good position. Repair the old pump at your leisure, and you've got a spare ready to go straight on. One of the things to rely on about seawater pumps is that sooner or later they fail, as you've found. Usually they fail but still work, as yours did, but not always.

Tip: if you rebuild a spare, make sure it has all the right hose barbs already assembled on it: makes a swap in difficult conditions very much easier.

 

[FairweatherDave]

Thanks both. I know I could have saved a lot by DIY but I certainly will repair the old one at leisure.....much more satisfying too.
If circumstances were different......