As the old saying goes.... "How long is a piece of string?"I like your fix here. Just wondering how much you stretch the spring. I would guess an extra 5mm.
I managed to stretch our spring a bit (Looked like about 2 to 3 mm) and it solved the problem for 12 months. Did it again on our last trip and have purchased a new valve (Different brand and 500kPa as opposed to the original 300/350kPa) from Master's for $15, a week before they closed. Now have it sitting in a cupboard in the van ready to swap over next time it plays up!