Raw water pump self destruction

[jlavery]

Hard 63 miles to windward yesterday from Gairloch to Mallaig in 18-25kts. Motorsailed for several hours initially to get through the chop.

Started engine approaching Mallaig - no raw water. SWMBO had a sense of humour failure. Used engine sparingly to berth.

Opened up pump to find... no impellor at all!

The bolt holding the internal cam in the pump had failed, allowing the now loose cam to shred the impellor!

All the debris ended up on the sea-side of the pump, not the heat exchanger (I've checked).

Very glad I was carrying an entire spare pump on board! Fitting it now (although need to acquire a gear puller to get the drive gear off the old pump).

 

[Porthandbuoy]

How on earth could that happen?

 

[Cardinal]

It seems that we should be checking that cam securing bolt!
Very lucky you suffered this so late in the trip.
Had the cam been disturbed or its position adjusted recently?

 

[jlavery]

It seems that we should be checking that cam securing bolt!
Very lucky you suffered this so late in the trip.
Had the cam been disturbed or its position adjusted recently?

Another thing to keep an eye on. But where do you stop? Engine is 12 years old, so had plenty of time to degrade. Cam hadn't been touched.

Interesting how completely impellor was destroyed. The catastrophic nature of the failure meant that nothing was sent further upstream towards the heat exchanger.

 

[Ribtecer]

I had that recently, only it was the bearings that went, not sure why as I specified (and paid for) stainless bearings on the last rebuild, they were completely shot.

Complete new pump and its a joy to now watch the temperature gauge.

 

[jlavery]

I had that recently, only it was the bearings that went, not sure why as I specified (and paid for) stainless bearings on the last rebuild, they were completely shot.

Complete new pump and its a joy to now watch the temperature gauge.

Is there a rebuild option? Apart from needing a new cam (and maybe worn bearings), the old pump is good. Tempting to just replace the cam and keep the old pump as a spare.

 

[Ribtecer]

Is there a rebuild option? Tempting to just replace the cam and keep the old pump as a spare.

What make is your pump? Ours was a Jabsco, and yes kits are available.

However based on our experience, a new pump was a much better option.

 

[jlavery]

What make is your pump? Ours was a Jabsco, and yes kits are available.

However based on our experience, a new pump was a much better option.

Original I think - Jabsco (on train to Fort William to get a puller right now).

 

[arc1]

Is there a rebuild option? Apart from needing a new cam (and maybe worn bearings), the old pump is good. Tempting to just replace the cam and keep the old pump as a spare

Have a look at parts4engines - I rebuilt mine (original fit to a vp2003) from one of their kits earlier in the year when it started leaking.

 

[Ribtecer]

Have a look at parts4engines - I rebuilt mine (original fit to a vp2003) from one of their kits earlier in the year when it started leaking.

My rebuild lasted 15 months!! Don't know how many hours, but I think it more about time sat with salt water in it.

With such an important part of the engine and therefore boat, I won't both next time.

 

[Thresher]

Another one! I posted about this just last week.

Broken screw on Volvo Penta impeller pump housing

 

[Thresher]

Another one! I posted about this just last week.

Broken screw on Volvo Penta impeller pump housing

 

[jlavery]

Another one! I posted about this just last week.

Broken screw on Volvo Penta impeller pump housing

Interesting, didn't spot that thread. Well my experience shows what happens when it results in full pump failure. Luckily didn't happen during the 5 hours of motorsailing earlier that day.

 

[Sandy]

That is impressive.

 

[ctva]

Original I think - Jabsco (on train to Fort William to get a puller right now).

If it is similar to a Johnson pump (looks like it), something like a 22mm deep socket in a vice will push the bearings out.

I rebuilt mine for £22 and kept as a spare.

 

[jlavery]

If it is similar to a Johnson pump (looks like it), something like a 22mm deep socket in a vice will push the bearings out.

I rebuilt mine for £22 and kept as a spare.

Thanks - yes, I'm planning to do that over the winter.

Mack Engineering are a good source for pump parts at good prices. Local engineer here in Mallaig put me on to them.

 

[ctva]

Also Scot Bearings.

 

[Ribtecer]

If it is similar to a Johnson pump (looks like it), something like a 22mm deep socket in a vice will push the bearings out.

I rebuilt mine for £22 and kept as a spare.

How much is a new engine? How important is water pump?

I tried to do it cheaply, and regret it. I was lucky.

I'm all for DIY, however a new pump has probably given my engine another 10 years.

 

[RivalRedwing]

A new pump from ASAP (or anywhere but Volvo) would be my choice, with the refurbed old one as a spare.

 

[jlavery]

A new pump from ASAP (or anywhere but Volvo) would be my choice, with the refurbed old one as a spare.

Yes, that's my plan. New one fitted, refurbing the old one for a spare.