Hello Paul... Sorry about the
I've had a couple of GR8 Jags...
(still got the last V12 convertible they ever made '95)....
Never knew they had a check valve (but it makes sense).
I'd first be looking at the pump motor itself
(they do get gummed up... simple cleaning sometimes... )
((white vinegar & soft bristles))
After that I have the FACTORY MANUALS...
Also used Captain-Jaguar's
"cat house" (Tulsa)
(eBay seller... previously Established business new &
used parts) and HAD some really great on-line forums
(I think he got tired (guess... like me twice re-TIRED)).
I found thru Captain Jag's (great resource... ASK...
He used to love Jags: http://www.ebay.com/usr/captain-jaguar?_trksid=p2047675.l2559
Also... look for you model on the
BBB Industry site
BBB Industries Premium Alternators Starters Power Steering Products
Also try Moss Motors & British Heritage searches
(free information (costly parts... opinion
but in my day... there was no other way to refresh a Austin Healey BJ8 (MK III, 3000)
captain jaguar on eBay
MossMotors com Restoration Parts And Accessories For British Cars