Having received the advice of the "wise men" on this Newsgroup about temperature variations on the gauge on my 1989 TD90, the next step is to consider a back-flush but I wonder whether this will put a strain on an 18 year old radiator (I think it is the original) and if not what kit to use - one I found on flebay seems to be a permanent installation and presumably has a stop valve resulting in the hose water backing through the system with potentially spectacular results
Comments/advice please (including suitable kit if recommended