I have read all of the threads and they have been helpful. I have removed the old tank and ordered a new one on line. I followed the advice to replace the lower fitting o ring. There does not seem to be a part number for the o ring. Jaguar dealer wants to supply a new line way complicated to replace I think when all I need is the o ring. One thread said to use the GREEN O Ring. It said it was the one in the AC compressor line? Does anyone know anything about this and where I can get the o ring. The old one did not look bad but now I went looking at a hardware store and in the process I have lost the old one.
The dealer parts folks are no help.
Thanks
Jack
XJ-8
Original owner '69 e-type still on the road

 

I replaced mine using an o ring from an assorted o rink pack. These are cheep and available at hardware stores, engineers supplies and on ebay

It is a lucky dip if you have the correct one though

If you take the plastic bolt to a hydraulic shop like enzed they will have the perfert one in stock and vey cheep

Cheers
34by151

 

The o ring I am looking to replace is the one inside the quick disconnect fitting which attaches to the bottom of the coolant expansion tank. There is no bolt. I could use the old tank which would fit the proper inside diameter but I would be guessing about the outside and the thickness
Jack
XJ-8, E-type

 

Remove the hose and the expansion tank and take it to a hydraulic shop
they will have no problem supplying you an o ring

By taking both the expansion tank and the hose you they can make sure it's a correct seal for you

You might also check the fittings going to the heater are the same and can be use as a reference.

Cheers
34by151