Joe won't blow

[DebW]

I bought a Joe Blow Sport pump about two years ago. Recently it decided not to engage with the valve on the tube about half the time. Air is coming through, so I don't know what the problem might be.

I got a "rebuild" kit from Topeak and nothing changed after I "fixed" the pump. Is there anything I should know before I call them back? I've tried the pump on about four tubes (why don't I throw tubes away?) and the problem is consistent.

Or should I just toss Joe and buy a new pump?

Have you replaced the o-ring on the pump head that seals it to the tube valve? Some pumps are particular about how tight you screw the cap onto the pump head, which makes the o-ring bulge out more or less. Try varying the tightness of the pump head cap.