Hello,New to forum, I have a 1984 XJ 6 Vandie, I noticed a humming noise coming the the rear of the car and thought it was the antenna sticking and motor contiuously running. I then isolated to spare tire well and it appears to be something call the right tank changeover valve. Has anyone had to replace this valve and if so how difficult. The Vandie is at 210000 and running strong but the humming drives you nuts.

Thanks
Gordon