Impeller will not pull out for replacement

[bobg]

I have tried to replace the impeller on my Lombardini inboard and it is locked solid. Double pliers, screwdrivers and bad language have all failed. I suspect that the screw on the impeller that fits on the slotted screw may have have rusted together. But I may be wrong. I have tonight sprayed it with WD, but club advice was to dismantle the Jabsco assembly to get at it.

Access to the bits involves being a rubber man. Is there any good tips on extracting an impeller that does want to be extracted?

 

[ShaunG]

You can go to your local chandlery and buy a dedicated impeller extractor, it has 2 arms that hook under the impeller and a screm thread to raise them under the impeller, they are not expensive, about £8. If you are familiar with car parts they look similar to a bearing extractor or one of the expensive ball joint pullers

Regards

Shaun

 

[Topcat47]

I've not come across a water pump impellor held in place by a grubscrew. That said, I've yet to find one siezed to its shaft either, and I've seen some pretty horrible ones. Mind you I've not had the pleasure of working on a Lombardini.

When you fit the new one, dab a spot of teflon grease over the drive shaft before fitting it. Any excess will be washed away by the cooling water, but the impellor will slide off OK at the end of the season (if we're talking standard Jabsco).

 

[steve_cronin]

You need the proper tool...

even if you have to make it yourself by getting a pair of long nosed angled pliers, heating the ends, bending them inwards and attacking the boss of the impellor with the so-formed ends in a vice-like grip and pulling the impellor firmly off of it's spindle with a few wiggles as you go. Yes. it works. believe me.

Steve Cronin

 

[PuffTheMagicDragon]

I don't know which model Lombardini you have but if it is like mine, direct drive from the camshaft at the back of the engine, the easiest is to remove the complete pump. I can then work comfortably and see what I am doing instead of trying to work upside down with my head down the cockpit hatch.

It is also easier to check the seals on the shaft and, if necessary, replace them. If you don't have a manual for your engine you can download diagrams from the Lombardini website that should give you an idea of what to expect. (Sorry if you already know this but I don't know how much you know)

 

[Poignard]

You could do what I do and have two pumps. One is fitted to the engine and the other is overhauled and kept on board ready to replace the other if necessary;it only takes a few minutes to swap them over. As someone else has said, it's much easier to work on the faulty one on the bench than on the engine.

 

[samwise]

Had a similar problem with the Johnson pump on our Volvo 2002. The inner metal collar on the impeller was pretty well siezed on to the pump shaft. Has a few goes with the needle nose pliers and then tried the two screwdriver lever trick, but I was risking damage to the machined face where the gasket and plate fits. So I stopped and bought a proper puller. The right tool plus some WD40 did the job. Bearing in mind the potential to seriously b**** up the whole unit with the butcher technique, I think the puller was a good investment.