I have a 71 with the push button controls,my problem is that the valve leaks vacuum . I took the whole control apart and cleaned it up,buttons and cable work freely and it did switch between floor and defrost a couple of times and then started to leak again. I know these are not the best heaters,but I like the original stuff when all possible. Is there any company that remakes the valve or the whole part maybe. Any help would be greatly appreciated. Thanks.