I'm looking for some procedures, tips or guidance on replacement of the XJS water pump.

An internet search shows info on other jag V12 models but not the XJS.

Thanks,

 

It is relatively straightforward; but is made much easier if you remove the radiator first. If you have not cleaned out the space between the water radiator and the oil cooler/condenser radiators, then you can do this vital cooling maintenance job at the same time. Also check carefully the condition of all the belts and change any hoses that look old and soft.
Then remove the cross pipe with the central filler spout from the engine (also renew this item's short hoses when reinstalling). You next have to loosen the drive belts in the way and take them out of the way. AT this point you can undo the water pump bolts/nuts, some of which hold the boss in place for the mechanical fan. Some of these fixings are studs with nuts rather than actual bolts.
One thing to look out for is the power steering pump and its belt. The PS pump has to be loosened off, and the belt removed out of the way, and one part of the PS pump tightening system has a
fulcrum on a water pump stud. So there are actually three fixings associated with the PS pump that have to be loosened to get this swinging freely enough to get this particular bolt or stud (forgotten which) out of the water pump housing to get the pump off. I refer to no. 13 or 15 on this diagram:



If the fixing I refer to is corroded in place, DO NOT FORCE IT, as if it snaps off you have a serious problem. If it will not turn when what should be enough effort is applied, heat the stud up to really hot, red or white hot, and let it cool right down, this should break up the corrosion. Take a whole day, or two, and go at it slowly and all will be well.
Greg

 

I'll just add the #17 is hidden from casual view and could easily trip up a first timer


Cheers
DD

 

Definitely pull the radiator, do not use a #2 tip on the #17 screw. Replace the nearby timing chain seal while you are there!

Not hard, just a lot of piece to come off out of the way and cleaning off old gaskets is always a chore. You may wanna grab a piece of cardboard to map out where the bolts go

 

Is the timing Chain seal also known as the timing chain adjuster plug. I looked for such a seal and only found the plug ( about $13 on Ebay). Is there only one to replace?

Thanks very much.

 

Yep. On the A bank side. Important: the old one will be dried out... So be careful when removing. Mine crumbled away and fell into the area there. Luckily I could get it out again...