Dripping raw water pump - how urgent to replace seal?

[NealB]

I've just noticed that the raw water pump (a Jabsco impellor type) on our BMC 2.2 Commander diesel is dripping water through the slots at the rear of the pump - about 1 drip a second at 1500 rpm.

I've ordered new seals from ASAP this morning (there's a pair of identical seals, one for water one for oil).

Is this an urgent job that needs to be done before using the engine, or can it be put off for a while (in other words, would I be daft to use the boat this weekend?).

Thanks for any advice.

 

[neale]

Do it asap. if your engine is anything like mine the salt water will be sprayed everywhere and make a right mess.

See this months MBM. page 92 has step by step procedure for replacing the seals.

 

[NealB]

Thanks for your reply.

The drips conveniently drop straight down into the bilge, clear of all engine bits, mounts, wiring, etc. so no real concern on that front.

 

[30boat]

I'd do it right away but if you don't want to miss the weekend it's probably ok to leave until later.If you come across a grooved shaft it'll take longer to put right.In case you need one, don't buy it off the counter,have one made instead,miles cheaper.

 

[VicS]

As others have said do it without delay.

It will only get worse, not better, as these things don't heal and it could get to the point where water is forced past the oil seal and into the engine crankcase.

While you are doing it make it a full pump inspection and overhaul. Replace the impeller, check the pump body for wear especially the end cover, the wear plate if it has one, even the cam. Inspect the shaft for wear especially where it passes through the seals.
Also replace the oil seal (as you intend to) and inspect the bearings as well.

A full pump overhaul kit would be a sensible purchase.

 

[BobnLesley]

Whilst not disputing that it'd be better done asap, don't panic or miss a day's sailing because of it. The unit on our Volvo MD6A dripped quietly for almost two months around the Western Isles in 2003 - I carry spare seals now.

 

[Adamastor]

Just to add more confusion- check the water dripping out. If you even suspect it's oily at all, you might need to get out of the office NOW and go and inspect the situation, with a view to looking at having a shaft made, ready to fit at your convenience. It's possible that the seals on the oil-end of the shaft might be "well-done", not completely toast. And if you've got any misgivings, ACT NOW! If the seals are still good, you'll feel good about your diligence anyway!
Are you gone yet?/forums/images/graemlins/smirk.gif

 

[wongaero]

At least it sounds better organised than a KAD32 - I wonder whether they deliberately put the seawater strainer and pump right over the alternator. Luckily they always seem to have a big stock of alternators... mmm?

 

[neale]

Ah yes, the one i referred to above was a KAD32.

 

[NealB]

Update.....

Decided to do the right thing, rather than risk long term damage. So, out with the tool kit for the....what, half hour job?....of removing, then dismantling the pump. With luck, the new seals will arrive from ASAP tomorrow, so the weekend will be saved.

But, in this cunning plan, I forgot something very important: it's a boat!!!

The first task is to remove the 3/4 inch copper inlet and outlet pipes. Problem....they're tucked away at the very front of the engine bay, right against a solid bullhead. Having spent an hour trying to get a variety of wrenches, spanners, grips etc. in a workable position, I gave up.

Tried to calm down, and think of plan B, with a nice cup of coffee.

Hmmmm......so what do? Cutting an access panel through the bulkhead would be a good long term solution, but will require the redesign, and rebuild of the companionway steps. I also don't like cutting boats up.

Hmmm.....what about removing the heat exchanger, alernator, stop solenoid and crank pulley? Seems a lot of dismantling just to get at two pipes.

No, no wait a minute....what about one of those plumber's basin wrench things? You know, the right angled spanner type things. Yes, that'll do it!

So, into the car, for the 5 minute drive up to Machine Mart on the Highway. Oh bugger, Friday afternoon, London, so it took over half an hour, and, to really rub it in, it wouldn't be big enough anyway (one of the pipe fittings is about 1.5 inches across flats).

Grrrrr.........three quarter of an hour drive (crawl?) back down Commercial Road.

Back on board, need to relax with a nice cup of coffee.

That's the state of play right now.

I've given up for the day, most frustrating.....hopefully the subconscious will come up with an easy solution.

Need to reduce my blood pressure, so off now for a soothing 15 mile run.

Thanks for all the replies, and apologies for this sad tale of incompetence.

Bloody boats!

 

[brianhumber]

Good luck

I think you are doing the right thing, when my seal went after muddy entrance to Villiane river, the trouble was not the drip but the very fine spray of salty water that dried white everywhere. Alternator bearing went 2 years later will never know if it was connected or not.
Also worth working out a get of jail salt water pump, I used a whale gulper pump to replace the pump as a trial, belive it or not a long sail ties worked better than I thought as replacement alternator/engine water pump belt. /forums/images/graemlins/smile.gif

B