Mark,

I don't think the torque specs are given on that instruction sheet, it just refers us to the manufacturer's specs. The torque specs may differ for the Land Rovers and Ford/Lincolns this pump fits. According to the X100, X308 and X350 Workshop Manuals, the water pump screws are to be torqued to 8 Nm plus an additional 90°. I've learned to do this with great care to be sure I don't overtighten a screw and break it, which may ruin your day (the one time it happened to me, I got lucky and it was in the easiest location to get a drill bit on it and use a bolt extractor.

If there is any indication of corrosion on any of the screws or in the screw holes in the engine, then before installing the new pump I clean the screws on a wire wheel and run a tap into all of the holes in the engine to clear any corrosion so the screws will torque up smoothly.

I generally just check that the two 10 mm screws that secure the halves of the water pump case are "snug" by feel, but you would probably be safe to torque them to 10-14 Nm.

The torque spec for the three screws that secure the pulley to the pump is 10-14 Nm.

The above specs are the same for the X100, X308 and X350 whether normally-aspirated or supercharged. Below is a snip from the X308 Workshop Manual section for the 3.2L/4.0L:




While I was pulling up the Workshop Manual, I ran across a TSB about the water pump impeller material so I'm attaching it for the benefit of future readers of this thread.

I once scanned the Airtex water pump instruction sheet/TSB, and if I can find the scans I'll post them.

Cheers,

Don

 

Thanks, Don. My manual has the 8nm+90, too, and I've always had a 'raised eyebrow' on that; just seems way too much for the bolt size. And today is not the day to break one of those bolts. I like the 12 to 14nm, then I can use my lucky number, 13, and all should be good.

 

8 Nm is a little less than 6 ft. lbs., and the extra 90° probably doesn't exceed a final torque of 14 Nm/10 ft. lbs. so it's really not much torque at all.

 

I'm attaching my scans of the Airtex TSB and Installation Instructions that come with the AW4124 water pump. They're not worth much, especially the instructions, which suffer from the same faint areas as yours. Better to use the Jaguar Workshop Manual. You can install JTIS on your own computer, or download a pdf version such as the one available from this forum at the link below:

Jaguar X308 Workshop Manual

Cheers,

Don