Has your Jaguar convertible's top started going up and down very slowly, or quit working entirely? If so, there is a good chance the hydraulic fluid has turned to jelly.
The hydraulic fluid Jaguar used from 1997 to the mid 2000s was prone to solidify and block the lines. It tended to clog worst in the valve up above the rear view mirror. The photo above shows a 1999 Jag with the header bar removed so the lines and valve can be cleaned out over the drain pan.
This problem is also the cause of excess stress on the hoses, which may manifest itself by lines that blow out and spray oil on the inside of the roof liner, or the dash.
So what do you do about this problem? You flush the lines and get rid of the old fluid and and chunks of gel. It's a bit time consuming but it's easier to do when the top still works. In that case, flushing and changing to synthetic fluid usually takes about three hours. Changing the hoses from the windshield header back is a bigger job; that usually takes all day.
Other than this, the convertible top mechanisms on XK8 cars is pretty trouble free. The only other service we commonly do is replace the canvas cover, which gets weathered after 8-10 years in New England.
Robison Service has specialized in Jaguar and other fine British automobiles for 25 years. We're located in Springfield, Massachusetts.