Weed Filter Removal

[BroadAmbition]

Nearest and Dearest stock  aquatic friendly anti freeze  Please use it or from another supplier. The normal stuff is deadly to marine life, birds included

Griff

[annv]

Hi Removing the impeller is only needed if engine is raw water cooled BUT as Andy said a lot of unnecessary work and possible damage you just do the same as sea water cooled but need more mixture to flush all round the water galleries and pipes of engine. a rubber/neoprene impeller will self prime if in good condition a steel one ie engine water pump wont it is just a water wheel. John

[Oddfellow]

1 hour ago, annv said:

Hi Removing the impeller is only needed if engine is raw water cooled BUT as Andy said a lot of unnecessary work and possible damage you just do the same as sea water cooled but need more mixture to flush all round the water galleries and pipes of engine. a rubber/neoprene impeller will self prime if in good condition a steel one ie engine water pump wont it is just a water wheel. John

This post seems to be trying to make a distinction between different cooling systems but ended up leaving an element of confusion with me. 

All we need to appreciate is that water will freeze and when it does, it expands and can break things: even solid metal such as engines. 

All water within an engine needs to be protected from freezing during the winter.

We can do this by putting an antifreeze mixture into all the water circuits of an engine regardless of how the engine is cooled. Direct raw water cooling, tank cooling, heat exchanger cooling, keel-cooling, whatever. 

 

 

[Vaughan]

To remove the impeller, or not to remove?

The last two yards I worked on, we passed antifreeze through the raw water side as described above.  A large watering can full would do the trick, diluted to give about -10 degrees on a hydrometer.  (That's in south France, of course!)

The impeller is then removed, the face plate and screws put back so you don't lose them and the impeller is left on the dashboard to show that it has been removed.

Why is this? Because if you leave it in the pump for several months, the same 3 vanes will be squashed up against the cam plate and will stay bent when you next start the engine.  We saw a photo of a failed impeller on another thread a couple of days ago and that looked to me to be caused by this problem.

Some yards (and owners) replace impellers every spring as a routine but if you have left it out for the winter and inspect the vanes to make sure they are not cracked, there is no reason not to re-use it.

Always smear the impeller liberally in special water pump grease before re-fitting as this will keep it soft and give a bit more suction to draw water up when starting the engine.  If you don't get any water unless you rev the engine to "prime" it, then you may also have worn front and rear faceplates.  In which case, ask the boatyard to change them.

[fishfoxey]

In which case if I intend to use the boat over the winter every 2 or 3 weeks or so, I assume I can do the antifreeze thing on the raw water but leave the impeller in. That way I just need to re antifreeze after each use?

[Vaughan]

39 minutes ago, fishfoxey said:

In which case if I intend to use the boat over the winter every 2 or 3 weeks or so, I assume I can do the antifreeze thing on the raw water but leave the impeller in. That way I just need to re antifreeze after each use?

Yes, but you must still take the impeller out in the spring to inspect and grease it, as routine maintenance.

[fishfoxey]

Thanks will do

[Vaughan]

By the way, be very careful not to lose the screws, as they have a special thread, known only to Jabsco!  Always use the genuine part.  If you try and use what "looks like" the right size setscrew, you will wreck the threads in the pump body.

[fishfoxey]

Thats a good tip, especially as the pump on the port engine looks easy to access but starboard looks tricky.

[Oddfellow]

49 minutes ago, fishfoxey said:

In which case if I intend to use the boat over the winter every 2 or 3 weeks or so, I assume I can do the antifreeze thing on the raw water but leave the impeller in. That way I just need to re antifreeze after each use?

That will get very expensive. Each Antifreeze action will use 5-7 litres of antifreeze. 

[fishfoxey]

I am thinking that I will keep an eye on the long range forecast and will add it as necessary. I am flexible in my job so worst case scenario is that if it looks bad can go up the day before and fill it.

[Cheesey69]

23 minutes ago, fishfoxey said:

I am thinking that I will keep an eye on the long range forecast and will add it as necessary. I am flexible in my job so worst case scenario is that if it looks bad can go up the day before and fill it.

Pretty much the same as me. Really want to use the boat as much as possible. So industrial size anti freeze and a tube heater just in case.....

[Meantime]

In 16 years of boat ownership I have never pumped any anti freeze into the rivers, aquatic friendly, or otherwise. Anti freeze always in the closed loop and changed and topped up as required. 2 x tube heaters in the engine bay on separate thermostatic plugs set to slightly different temperatures. Small one comes on first and usually does the job, larger tube heater comes on second if first one not providing enough heat or should it fail. 

I use the boat throughout the Winter and just turn up, open the seacock and turn the tube heaters off and away I go.