I have a 98 XK8 with an actual 33k original miles on it and everything on the car is original. One thing I noticed from early on was that the convertible top latch was sticking- moving very slow going up and down. It was so slow in fact that you can hear the top rams straining to open the top and finally the latch moves just enough to release the top and we're open.

The car had the yellow fluid in it which I recently changed to green. I removed the latch assembly and purged the hoses up front until nothing but green came out. I also tried to purge out the latch cylinder itself which is a little harder to do. The latch assembly seems to move ok in manual mode, but is slow moving with hydraulics. Could there be a hangup inside the cylinder itself?

Also, I tested the refilled system with the header cover off and am noticing the hoses move (physically, like up to 1" ) away from the A-pillar/windshield header during some operation. All of the standard hose hardware is there. Is this normal? It will be covered by the header panel when done, but it doesn't seem right. Maybe one of the hoses got twisted on install?

Any thoughts would be appreciated.

 

I have a 2006 XK8. I'm not sure how applicable this might be to yours, but when I acquired my XK8 the top had trouble opening. Sometimes it worked (slowly) other times I had to push up on top near the latch to get things moving.

Now, with no intervention, it works fine every time. All I can think of is that the top hadn't been used and lube or air bubbles eventually were located where needed.

Not much help...

 

Depending on when you replaced the fluid you could have air in the lines but that will work its way out. It is a self purging system. It could be that you need to lubricate the latch and ram piston shafts. You can use WD40 to clean the shafts and see what takes place. The ram and latch pistons have “O” rings and seals that might be dry or dislodged so give the lubrication a try. I would also recommend checking the fluid level and the petcock closed.

 

Yeah, it could be a use thing. The car sat unused for 3+ years and the top was put down maybe once. I disassembled the latch and it seemed to be the cylinder itself that is slow moving. Maybe with some use it will get freed up.

I have a parts car here and the cylinder in that one is much smoother, but I understand it has leaks- that may be why it moves freely......

 

If you have an extra latch, why not send it off to be rebuilt and swap them out when it returns.

Wayne

 

my xk8 has been working fine then when driving came up on dash not closed properly stopped went through procedure seemed fine but now wont open making all same noises sounds if catch stuck will try push up any other advise would be appreciated

 

Try opening the latch manually with the hex key.

 

Check your fluid level.

 

Thankyou charged battery tried this morning still same was unsure whether to try manual operation as it says not to in manual

 

unlocking roof can I manually open

 

Still haven't been able to open bit nervous opening manually have tried everything else fluid levels bit low how easy to top up 😂

 

UNIVIS was the fluid used when your car was made.
We got a TSB when I worked at the dealer for replacing the fluid with Pentosin CHF 11S.

You need to drain the reservoir (suck out old fluid), fill the reservoir with the green Pentosin, remove the top rail and the hydraulic lines from the cylinder to bleed the yellow UNIVIS until you get a steady flow of GREEN.

The lift rams will self bleed due the volume of the cylinders but the latch cylinder is so small that the fluid stays in the LONG lines and won't displace enough fluid to bleed.

I have done DOZENS of fluid replacements when I worked at the dealer.

TSB for you.

P.S. I still have a partial container of UNIVIS that nobody wants in their car.