Beta 25 water pump fail or my poor heat exchanger reassembly?

[FairweatherDave]

So my normal winterising routine is to suck up some antifreeze into the sea water side from a bucket. Then before launch run the engine up ....using the same pipe drawing from a bucket. A beautiful thing to watch providing you keep the bucket full. Today a complete fail. Tried a new impeller and the old one. The pipe to the heat exchanger is clear. And I could blow down the pipe from the heat exchanger. Over the winter I rodded the stack and replaced the engine antifreeze. In desperation I double checked my reassembly of the heat exchanger and I'm sure it is correct....I know it is the right way round with the notches...So twice I got a little water sucked up but then it stopped....I gave it a reasonable chance. Does this sound like new water pump time? I think it's about five years old.

 

[neilf39]

When the engine is cold the heat exchanger is being bypassed by the thermostat so not that. Leave the cover off the impeller to see if the water pump shaft is turning the impeller. Has the cover gone on ok and did you put in a new o ring? Any air getting in to the pump will stop it working

 

[FairweatherDave]

When the engine is cold the heat exchanger is being bypassed by the thermostat so not that. Leave the cover off the impeller to see if the water pump shaft is turning the impeller. Has the cover gone on ok and did you put in a new o ring? Any air getting in to the pump will stop it working

Thanks Neil. Good to know its not the heat exchanger. I did turn the crank manually with the cover off and watched the impeller rotate. No I didn't change the O ring so that is something I could try, however I do change or replace the impeller every year and pretty sure the cover has gone on as usual. I guess I am interested in the life expectancy of water pumps and how they fail - if that is what it is.

 

[Pye_End]

Is this via the skin fitting?

Is the valve open?

Have you had the lid of the strainer off? Could be air getting in there.

 

[LittleSister]

Thanks Neil. Good to know its not the heat exchanger. I did turn the crank manually with the cover off and watched the impeller rotate. No I didn't change the O ring so that is something I could try, however I do change or replace the impeller every year and pretty sure the cover has gone on as usual. I guess I am interested in the life expectancy of water pumps and how they fail - if that is what it is.

Very unlikely that a raw water pump would completely fail.

With age they usually just get less efficient as the cam and front & rear faces wear and/or the shaft seals wear resulting water leakage along the shaft (which should be visible via opening in shaft housing to rear of pump, and if so needs fixing to ensure that water doesn't get further and into the engine).

You've seen it rotate, so it's almost certainly not drive or shaft failure. You've tried old and new impeller, so it's almost certainly not duff impeller with the rubber vanes moulding detached and failing to rotate with the metal hub. It was working before winterising, so unlikely so worn won't pump.

As suggested above, check cover is properly seated. (I doubt a worn O ring alone would make enough difference to stop it working.)

Did you wet or grease the impeller? Perhaps pour a little water down the inlet pipe to help the vanes seal to raise the first of the water from the bucket.

Have you changed or accidentally disturbed the pipework in any way? Checked that the inlet pipe (from the bucket) is airtight at the pump end?

 

[Kwik Decision]

Is the pump cover plate worn? They need to be flat, if there's grooves worn in, that could prevent the pump from priming. You could try turning it round...

 

[FairweatherDave]

Is this via the skin fitting?

Is the valve open?

Have you had the lid of the strainer off? Could be air getting in there.

No, from a container in front of the engine compartment. 30 cm long pipe. Easy to keep the pipe end submerged.

 

[BabaYaga]

When the engine is cold the heat exchanger is being bypassed by the thermostat so not that. Leave the cover off the impeller to see if the water pump shaft is turning the impeller. Has the cover gone on ok and did you put in a new o ring? Any air getting in to the pump will stop it working

Thermostat is in the fresh water circuit, sea water should flow through the heat exchanger tube stack regardless of engine temperature.

 

[BabaYaga]

Did you wet or grease the impeller? Perhaps pour a little water down the inlet pipe to help the vanes seal to raise the first of the water from the bucket.

^^^
Or some glycerine on the impeller.

 

[FairweatherDave]

Very unlikely that a raw water pump would completely fail.

With age they usually just get less efficient as the cam and front & rear faces wear and/or the shaft seals wear resulting water leakage along the shaft (which should be visible via opening in shaft housing to rear of pump, and if so needs fixing to ensure that water doesn't get further and into the engine).

You've seen it rotate, so it's almost certainly not drive or shaft failure. You've tried old and new impeller, so it's almost certainly not duff impeller with the rubber vanes moulding detached and failing to rotate with the metal hub. It was working before winterising, so unlikely so worn won't pump.

As suggested above, check cover is properly seated. (I doubt a worn O ring alone would make enough difference to stop it working.)

Did you wet or grease the impeller? Perhaps pour a little water down the inlet pipe to help the vanes seal to raise the first of the water from the bucket.

Have you changed or accidentally disturbed the pipework in any way? Checked that the inlet pipe (from the bucket) is airtight at the pump end?

Thanks for your thoughts. It feels an abrupt fail, hence why I question my servicing. Previously it would draw up coolant with a pretty casual temporary connection to the pump...but I checked that and put on a few wraps of tape and a new jubilee clip. I must have had the cover plate on and off five times and it looks good to my untrained eye.... I will certainly try a new O ring next visit but still feel I'm barking up the wrong tree. No glycerin but a bit of a wipe with fairy liquid.

Why I'm perplexed is it seemed to draw well for a few seconds and then stopped......as if the exit was blocked.....

 

[FairweatherDave]

Thermostat is in the fresh water circuit, sea water should flow through the heat exchanger tube stack regardless of engine temperature.

Interesting. Hence my question at the start. Obviously I need to go and try more things out and I hope to get a call back from Beta, who have always been excellent. The system looks so simple...

 

[LittleSister]

Thanks for your thoughts. It feels an abrupt fail, hence why I question my servicing. Previously it would draw up coolant with a pretty casual temporary connection to the pump...but I checked that and put on a few wraps of tape and a new jubilee clip. I must have had the cover plate on and off five times and it looks good to my untrained eye.... I will certainly try a new O ring next visit but still feel I'm barking up the wrong tree. No glycerin but a bit of a wipe with fairy liquid.

Why I'm perplexed is it seemed to draw well for a few seconds and then stopped......as if the exit was blocked.....

Check the exhaust elbow, perhaps?

 

[FairweatherDave]

Check the exhaust elbow, perhaps?

That's the thing. I took it off over the winter thanks to excessive attention to the forum and checked it was clear....it was fine. I will double check the exit pipework for socks stuffed into the exhaust etc but really hope I'm not that dumb.....

 

[Tranona]

Rather than suck the water out of the bucket, close the seacock and fill the filter bowl. Leave the lid off and have a jug of water ready to top it up once the engine is running. That will prime the pump. At tickover the water flow is low so you can easily keep it topped up until the water comes out of the exhaust. I prefer this method to sucking out of a bucket and actually modified a bucket with a skin fitting in the bottom and hose feeding the filter bowl. The bucket sat on the bridge deck with 3 or 4 litres of water in it. If you have access to a hose supply of water then a simple cock on the end of the hose so you can reguate the flow then again into the filter bowl. This is what I use now as there is good water supply in the club yard.

 

[PetiteFleur]

As Tranona says - I had similar problem a while ago - had to make sure the water filter screw top was well greased so no air entered. Made a special tool so the lid could be screwed on tight.

 

[Scomber]

That's the thing. I took it off over the winter thanks to excessive attention to the forum and checked it was clear....it was fine. I will double check the exit pipework for socks stuffed into the exhaust etc but really hope I'm not that dumb.....

Hi , I go straight from bucket like you then direct to impeller , beta 25 , always have. Am I right in thinking you go direct to impeller not onto the raw water filter first ? Sorry if Ive missed it somewhere.

 

[FairweatherDave]

Yes, straight to the impeller/ pump.

 

[Tranona]

Having the head from the filter will almost certainly solve the problem of priming. Once the engine is running, leave the seacock closed until you get into the water, Put the cap on, open the seacock and everything should be OK.

If it all worked before, nothing you have done would seem to have changed anything.

 

[FairweatherDave]

Having the head from the filter will almost certainly solve the problem of priming. Once the engine is running, leave the seacock closed until you get into the water, Put the cap on, open the seacock and everything should be OK.

If it all worked before, nothing you have done would seem to have changed anything.

Thanks Tranona. I like your idea and will try it. Along with the O ring. Adrian at Beta says the symptoms are not water pump symptoms so I need to persevere..... frustrating when the way I have done things for 7 years seems to be failing.

 

[FairweatherDave]

Update. Mission accomplished, we have flow.
I replaced the O ring, used a bit of silicon grease on the impeller and reversed the cover plate. Kwik Decision and Adrian at Beta prompted that - I hadn't inspected the plate properly and it was scored. I didn't try the water intake from the strainer as I didn't want too many variables changed at once, but once the pump was primed I switched over and tried out that technique. My batteries are under the quarter berth in close proximity to the strainer/water intake so it is not the ideal place if my pouring were inaccurate - but it does have the potential to be a lot easier not switching the pipes over at winterizing time for flushing/adding anitfreeze. But the O ring did look somewhat flattened so cheers Neilf39! And thanks to everyone who ignored my paranoia on the heat exchanger and didn't suggest it sounded like a water pump failure (LS and Tranona). Hopefully launching a week tomorrow so that was big relief.