The water pump (EAC 2109 PA) from my 1976 XJ-S looks very good. The air pump (7801149) doesn't look to bad either. Can I rebuild either one myself? What tools would I need? Or should I ship them to a professional refurbishing company? Ideally I want exactly MY water pump and MY air pump back, not an exchange. Does anyone know a good shop that they have experience with?

I also found this broken off nut that looked like it fell out of the water pump. Any idea where it goes?

 

Why do you want to re-do the air pump? Why not get rid of all of the plumping associated with the entire air pump system.

 

The nut looks like it may be the bearing indexing screw locknut from the underside of Waterpump partly hidden by the pulley.
It has been sometime since l bothered to rebuild a Waterpump since new pumps are available at a very reasonable price.

 

As my pump had corroded badly inside and outside I bought a new one. Problem is, the earlier models supposedly had a slightly different pump... I think it was the pulley or so. Actually it was the pulley. Later models had a single grove pulley ...


Anyhow. Your pump is more related to those of the E-Type and you can source all parts for them nowadays. You can get the bearing, impeller, pulley and co still new. Overhauling isn't that hard anyway. You MIGHT have to press the bearing out... Some seem very stiff, others are held in place via a grub screw...

 

That nut also looks like it was on one of the 4 studs BUT you need to remove other parts before you can access them. So it must have ripped off before. There are no parts in the water pump that habe a nut on them. The impeller and pulley are both pressed on.

 

Found one of my very old pumps. Nut and screw which l believe is the orphan you have there can just be seen centre of pic under Edge of pulley. It needs to come out before pressing bearing out anyway so may have saved you the trouble.

 

The little screw is actually sheered off. It ends at the little nut (not me!) and is ground nice and smooth on the bottom. I guess I will get a rebuilt one with a double pulley and send in this one as a core.

 

Thank you for sharing this valuable information...