It pumps air fine, but the pressure gauge falls down after every pump.
This person had the same problem, but they ultimately returned the pump rather than buy a replacement part.
http://www.bikeforums.net/showthread.php/539488-Floor-pump-gauge-problem
How much the gauge rises seems to depend on degree of obstruction. If chuck is empty, it reaches 0.5 bars (then falls back down). If a presta valve is screwed in, it reaches 20 psi (1.5 bar).
I suspect that air is escaping between the chuck and the valve. With my thumb plugging the empty chuck, the gauge will gradually rise as I force the handle down, and gradually fall as I let air seep out. I suspect that the pressure gauge only works when it is a closed system, but it is not a closed system because air is somehow escaping between the chuck and valve.
I took the pump apart and lubed or greased everything. No difference.
I even put some Pro-Line lube onto the gasket of the spring-loaded thingy beneath the gauge (video).
This person had the same problem, but they ultimately returned the pump rather than buy a replacement part.
http://www.bikeforums.net/showthread.php/539488-Floor-pump-gauge-problem
How much the gauge rises seems to depend on degree of obstruction. If chuck is empty, it reaches 0.5 bars (then falls back down). If a presta valve is screwed in, it reaches 20 psi (1.5 bar).
I suspect that air is escaping between the chuck and the valve. With my thumb plugging the empty chuck, the gauge will gradually rise as I force the handle down, and gradually fall as I let air seep out. I suspect that the pressure gauge only works when it is a closed system, but it is not a closed system because air is somehow escaping between the chuck and valve.
I took the pump apart and lubed or greased everything. No difference.
I even put some Pro-Line lube onto the gasket of the spring-loaded thingy beneath the gauge (video).