Hi Mark
Sounds like from what you are saying the old temperature bulb is stuck in the hole providing the nuts not broken in the hole and still holding the bulb in. Bulb meaning a part like is attached at the cylinder head end of your new gauge. The old temp line is maybe snapped off from what you say, if not it doesn't matter if you snap the cable off if it's not working
.
To get them out I have tapped on them with a hammer and small punch to loosen them. Providing the nut's all come out, taking care not to damage the casting or threads in the hole then pulled the old bulb out with pliers. this works on old damaged ones like yours usually.
The seat it fits in is tapered slightly to seal it tight with the nut. If they are real tight and that don't work remove the cast fitting that the top radiator hose is clamped to. Remove the thermostat if fitted. then you should see the end of the bulb inside the head. carefully lever it up from inside the head. It should pop up, if it's an original and never been out, 60 plus years of corrosion is holding it in you may have to tap it with a punch inside to loosen it.
Have done a fair few working gauges when doing clutches and motor work. This is how I do it on those gauges and have never destroyed a gauge yet by snapping the end off with the second method
.
if part of the nut is still in you got a larger problem to deal with
.
I have never done this on a snapped off bulb but you might find you could put a big self tapping screw in the top and pry on that also, to lift the bulb out
If you take the thermostat housing off, make sure you clean all the joining surfaces and fit a new gasket/ re seal it good .
If you find the thermostat is missing it might be an idea to replace it, your tractor should hopefully run warmer and better with it in. Hopefully it's there as sometimes guys removed them to stop/ hide other problems also
Regards Robert
