Air compressor on/off valve problem

My “antique” air compressor has a defective manual on/off valve. It leaks and allows air to escape the tank when in the off position. I’m trying to come up w/a solution. The valve is an integral part of a manifold ass’y that screws into the tank, one port of which holds the pressure-controlled automatic on/off switch, another the over-pressure safety release valve, and the output port, which goes to the hose and two other gauges. Any ideas what that manifold with the on/off valve would be called?

Do you see it here @George_San_Jose1?

but it occurs to me that if that valve is leaking the leak would cause the compressor to turn.

No. This manifold contains an integral slider which is the main on/off valve. It has a big red button on one side, and a black button on the other. You push it one way to turn it on, and the other way to turn it off. I can always make it from separate parts, sort of like this I suppose.

Yes, the leaking valve causes the compressor to turn on, when otherwise it would remain off.

The valve that’s leaking is probably the one that relieves the pressure during starting. You’d need to get your specific manifold from the compressor manufacturer.

It’s a manually operated valve, nothing to do with the compressor, similar in function to the small red valve in the Amazon photo above. Only it isn’t a twist on/off type, it is a push on, push off slider type. I’m starting to think the push on-push off slider type isn’t made any more. b/c it isn’t reliable.