How to: Replace a burnt-out impeller 

You can use dishwashing detergent as a lube for the impeller and it gives you a visual check that the impeller is the right way around and working correctly by seeing the bubbles rising outside the boat.Dont know about the bellows have not done them but should be fine.

I use aluminium grease

Or silicon grease is good for any rubber that needs lubricated it also doesn’t pick up much dirt and particles which is useful when maintaining the impeller

+Russ Cattell Simplest answer is probably to just remove the whole pump, you will need to loosen both jubilee clips and remove the pipes, be careful as the bottom one may be below the waterline so plug the pipe. now it s 2 x 12mm bolts either side of the pump, you will need a socket and an extension these secure the pump on, now wiggle it forward, remember you will need new gasket or some gasket cement for reassembly. Take the whole pump off and it all becomes much simpler. I do the same on out boat as room is tight. Takes about an extra 10 minutes. Jon

Thank you for your help Jon. That all makes sense to me.