Water pump impeller lifespan

Previous boat had a Jabsco on a Perkins 4108. I did a precautionary change after runing the ICW in the USA, the stretch up the Potomac to Washington DC was full of silt. That impeller was 5 years old and still looked OK when removed.

Current boat has a Johnson on a Perkins 4154. The impeller has not been changed in 6 years but it get fed nice clean seawater and I usually sail rather than motor.
 
Ford Sabre with Jabsco water pump. Change about every 4 years. The secret is NOT to take it out over the winter but leave in the engine in a fresh water/antifreeze 50:50 solution. That way it doesn't dry out. When installing a new impeller I lubricate it completely with Turbo gel, rubbing it well into the veins.
Prior to using this method I was occasionally losing vanes...great fun finding them!
 
I have found that leaving in situ over the winter causes corrosion of the cover plate on the Johnson pump even with anti freeze soluble oil mix. I assume that the pump does not stay full of liquid over the winter and eventually condensation forms gets trapped between the rubber and cover and starts to cause corrosion. Its also probably not a good idea to leave the pump impeller in the same position for a long time with one vane bent over. I also wonder if changing the impeller more often than the manufacturer recommends is bad for the pump as well as the wallet.
 
All of you who live close to your boats are so lucky. The advice to remove the impeller for the winter sounds sensible but we have to leave our boat in commission so the yard can move her to the slings for the winter lift out. I change the filters before I leave her but that is all I can do.

These days a 650 mile round trip costs a considerable amount in fuel so I cannot just pop up for quick jobs. Think I will ask the boatyard to remove it when they take the mast down.
 
Storyline said:
All of you who live close to your boats are so lucky. The advice to remove the impeller for the winter sounds sensible but we have to leave our boat in commission so the yard can move her to the slings for the winter lift out. I change the filters before I leave her but that is all I can do.

These days a 650 mile round trip costs a considerable amount in fuel so I cannot just pop up for quick jobs. Think I will ask the boatyard to remove it when they take the mast down.
Click to expand...

Presumably, if you can't do it yourself, you get the boatyard to winterise the engine, and fresh water systems etc etc?
 
FullCircle said:
Water pump failed on my 3YM30 after 500 hours, a known problem

First impeller failed at 42 hours.
Next one got changed with the new water pump at 500 hours
Currently showing 930 hours, but I am going to change it this season. I am expecting the water pump to start leaking again in 1-200 hours.

Personally, I can change an impeller in around 6 minutes, so I am not really that bothered about changing religiously
Click to expand...

What engine please?
 
KAM said:
I have found that leaving in situ over the winter causes corrosion of the cover plate on the Johnson pump even with anti freeze soluble oil mix. I assume that the pump does not stay full of liquid over the winter and eventually condensation forms gets trapped between the rubber and cover and starts to cause corrosion. Its also probably not a good idea to leave the pump impeller in the same position for a long time with one vane bent over. I also wonder if changing the impeller more often than the manufacturer recommends is bad for the pump as well as the wallet.
Click to expand...

I think you have identified a significant problem ,by leaving the impeller in it does mean that probably two vanes are bent for up to 7 months in one position.
I had an overheating problem this year which was down to a number of factors, mainly the blocking up of the small vent hole in the Volvo penta thermostat housing, but certainly not helped by two lugs of the impeller vanes having broken off and restricted the flow of sea water cooling.
 
NormanS said:
Presumably, if you can't do it yourself, you get the boatyard to winterise the engine, and fresh water systems etc etc?
Click to expand...
Sort of, we do the water before we leave but as regards the engine I am not sure what winterising it is. I change the oil so it can bathe in clean stuff all winter and check the coolant/antifreeze is topped up but what else does it need ?
 
Storyline said:
Sort of, we do the water before we leave but as regards the engine I am not sure what winterising it is. I change the oil so it can bathe in clean stuff all winter and check the coolant/antifreeze is topped up but what else does it need ?
Click to expand...

One additional thing that I do, is to run the engine when ashore, introducing antifreeze into the salt water side. This is so that any water left in the exhaust system, (water trap and muffler), will not freeze and burst something. Some people then bung up the exhaust outlet.
 
If I'm staying in the water, the impellor on my VP2003 gets removed and inspected every spring. I don't remove it for the winter because I have to move the boat from the mooring to the club pontoon to do the winter jobs, so it gets a good run - enough to get the oil good and warm at least every couple of months. If I come out, so does the impellor.

If it looks OK, it goes back in. I usually get 3-4 years out of an impellor, but I'm hypercritical when examining them, I could probably get double quite safely.

A bit of Fred Drift: Since I fitted two cartridge fuel filters in parallel, running on one and able to switch to the other at a moment's notice, I've regarded them as change on fail parts. I'll change 'em this year 'cos they're getting so rusty they could start to leak in a year or two, but I've had the best part of 8 years out of 'em.
 
I have a speed seal but have found that it leaks. To stop the leak I have had to reinforce the o-ring with some gasket sealant and then tighten up the knurled knobs with a pair of pliers - which rather negates the point of the speed seal which is to be able to make a quick impeller change. If it leaks again I am planning on returning to the original face plate with paper gaskets.
 
As the boat is being lifted, I usually run a bucket full of antifreeze through the engine. Leave the impeller in place over winter hard standing and replace with a new one immediately prior to launch. One season, the removed impeller had lost a blade. Never found the blade nor the reason for its failure. For me, that's reason enough to stick with yearly change.

Outboards, on the other hand, as we all know, are designed with "an impeller if for life, not just for Christmas" in mind :)
 
davidjackson said:
As the boat is being lifted, I usually run a bucket full of antifreeze through the engine. Leave the impeller in place over winter hard standing and replace with a new one immediately prior to launch. One season, the removed impeller had lost a blade. Never found the blade nor the reason for its failure. For me, that's reason enough to stick with yearly change.

Outboards, on the other hand, as we all know, are designed with "an impeller if for life, not just for Christmas" in mind :)
Click to expand...

Broken impeller blades usually end up blocking off some of the tubes in the heat exchanger. Unfortunately, they seldom just disappear.
 
NormanS said:
One additional thing that I do, is to run the engine when ashore, introducing antifreeze into the salt water side. This is so that any water left in the exhaust system, (water trap and muffler), will not freeze and burst something.
Click to expand...

Same here. There is a drain point on my water trap, but I can't get to it.
 
Ric said:
I have a speed seal but have found that it leaks. To stop the leak I have had to reinforce the o-ring with some gasket sealant and then tighten up the knurled knobs with a pair of pliers - which rather negates the point of the speed seal which is to be able to make a quick impeller change. If it leaks again I am planning on returning to the original face plate with paper gaskets.
Click to expand...

It sounds like some distortion in the pump flange. A flat sheet of glass and some very fine sandpaper or valve compound might well sort it.

Richard
 
You must log in or register to reply here.

Share this page

Top