Originally Posted by Mark Johnson
I have the same set up, and recommend the head
and this pump highly. It is a very well engineered, reliable pump.
I know it's two years later, but I have to chime in: the Henderson Mark V (now made by Whale, etc.) is not, IMHO, well-engineered. At least one valve is (if I recall
correctly) held in place by sheet-metal screws that go through a rubber-encapsulated steel
piece (which adds rigidity to the valve) and then into the plastic body of the pump. Not surprisingly, eventually a little bit of dampness reaches that steel
piece, which corrodes and warps, after which the valve doesn't close very well. And of course, after a couple of replacements
, the plastic into which the sheet-metal screws go...it's starting to get weak, too.
Furthermore, the screw-on cover isn't particularly beefy, and an enthusiastic pumper, working against, say, a closed through-hull fitting, can make stuff ooze out around the O-ring seal. (Ask me how I know...) I suspect that a strong one might make the cover blow off, and that could be REALLY ugly.
The "stems" to which the hose attaches are, as I recall, neither the right diameter for US hose, nor long enough to fit two hose-clamps on properly.
Also, the O-ring appears to be metric, which is OK, but hard to replace in the US. Of course, you can buy one for 10 times a reasonable cost from the manufacturer, but ...
Anyhow, after several years of screwing around with it, I threw mine away. I'd managed to make everything else in the head
system pretty much smell-free, and that pile of junk just ticked me off.