Okay, my very experienced fellow members, here’s a puzzle.
‘My 77 XJC had a rebuilt XJS rack installed last year. By the end of November when I put it away the steering effort, especially at slow speeds, was getting high. Most noticeably, the input is easy for about 1/4 turn and then becomes harder, almost manual steering harder.
The car, although Chevrolet converted, has a Jaguar PS pump fitted. For all I know it’s the same one that was original to the car when it was converted in 1995 by the second owner. Before the rack was replaced the pump did get run dry on occasion.
So although the system is holding fluid fine now, and the PS pump is quiet, is there anything other than a replacement pump I should be looking for?
Thanks

 

OK, my take on this from too many Jags, V12 and 1/2 size engines.

Saginaw pump, NOTHING special, GM, Ford Toyota, Jag etc.

The HIGH pressure fitting in the pump, the one the High Pressure pipe attaches to, is SPECIFIC to the brand of vehicle, and the pressure for that system.

I have swapped out a few pumps, using the Jag mount brackets and that fitting, nothing weird happened.

Being run dry, even for a second, has possibly killed the innards, and now it dont like you no more.

Kits are available, and so are rebuilt pumps, just swap the brackets and High pressure fitting.

XJ6/12, and XJS up to late 80's are the same basic rack. Some a tall pinion mainly up to about 1977ish,, some are squat pinion (later spec racks), with corresponding lower column shafts to suit.

There is some banter around that the S3 racks were different ratio, dunno, never paid much attention when I needed a rack, the pinion height matching was the key for me.

 

Thanks for the input.
I did further research; the conversion was extremely well documented and the pump is the stock Chevrolet unit that came on the ‘91 L98 motor.
So I’ll be getting an under $100 GM Saginaw replacement, instead of the $350 Jaguar branded GM Saginaw replacement.