Le Nivex gauge pump

[davidwheeler]

Has anyone managed to get inside one of these?   I think from pictures on the net that the bottom unscrews but have not managed to do this and I don't want to force things.    It has lost all its pressure ability, I suppose there is some sort of non return valve in the piston?

[Tony Stephens]

Mike Benwell seems to know his way around Nivex gauges

[davidwheeler]

I could faintly see aline round the end indicating a cap but I could not undo it.  I made a very thin tool for the lathe and cut away the cylinder so as to take the pressure off and was then able to unscrew the cap - desperate measure but it worked.    Inside is a piston with a thin and perished cup washer.   I bought a cup washer but it is too thick and would need I make a new smaller piston. I tried making a cup washer but no good so I simply fitted a couple of plain leather washers - and it seems to work!