I've owned various HP and HPX pumps for more than 20 years and never experience this before.

I have a new HPX (ASV) pump which has only been used on a couple of occasions. It has never been dropped or misused and still appears to be in virtually new condition. BUT... today, just when I needed it (of course) the pump failed to inflate a punctured tube.

After returning home I discovered the problem is that air is now also exiting the pump head from the thumb-lock side of the pump head, rather than exclusively pumping into a tube valve.

No parts are missing and this model accepts both Schrader and Presta valves without switching or flipping the valve washer, so nothing internal was ever messed with since purchase. I have an identical pump in a different length and it still works fine after a lot of use.

Is there any sort of consumer repair I can make to what I assume is a blown internal seal somewhere in the pump head? I don't even know if such parts are even accessible, but I would think the thumb lock retaining pin (spindle) could be punched out to remove the thumb lock lever. Unfortunately, only the most basic and obvious replacement parts for this pump are shown or listed on the Zefal website.

Appreciate any advice. ~ Thanks!

Here are a couple photos showing this latest "ergonomic" model which features their traditional alloy construction, and now with soft rubber grips on the handles and a slightly angled pump head: