PSI Pump

Bumping.

Sounds like the guage is defective. If you've not had the pump long, and still have the receipt, I'd take it back... head to the local bike shop that sells race parts and get a good pump.

I love the Silca track pumps. Not the cheapest but they're solid and will last for years. Cannondale has a nice metal pump too - not quite as nice as the Silca but still it ain't shabby.

A couple of things to look for in a track pump:

Big handle and big base - great for those times where you 'graduate' to race wheels with tubular tires for time trialing and you find yourself needing 150psi when on a smooth concrete surface.

Replaceable rubber inserts - important if you use inner tubes that have threaded valve stems.

Metal parts - plastic breaks eventually. After years of being put in the back of a car, where it gets pretty hot, when you go to races, plastic and rubber bits tend to fail. Metal is king. Queue Beavis and Butthead. Dun dun dun dun dah!

Have you carefully examined the tube to ascertain where, exactly, the leak is? Is it at the base of the valve stem? If so, you are abusing that area when attaching or removing the pump head to/from the valve (i.e., bending the valve this way and that when you attach/detach the pump). Is there a bit of glass poking through into the interior of the tire? Always check the tire carefully every time you find it necessary to replace a tube.