Thanks for all the suggestions and support. I put a couple of pics here which show what I did
http://s751.photobucket.com/albums/xx151/maxkirby/Triumph%20spindle%20fix/After riding it yesterday for a little bit I put a sheet under the bike to see if it leaked anywhere and this morning it was fine. I went out for a 45 min run at lunch time today, stopping and starting a number of times without incident. Fingers crossed for the future!
Cheers
Max
