Time to necro this thread with an update and some pictures!
I bought an old HPX size 4 a while ago for very little money and I too wanted to dissasemble it to polish everything.
So let's tear it apart to figure out how it works.
As several have mentioned before, the inside of the pump handle has two notches.
Don't bother with those. My guess is they use two parts to slide it in there instead of making it out of a single piece. No amount of turning seems to do anything.
What you
should be looking at is the
cap that switches between modes. It is made of a very tough plastic (probably nylon or something) and is held together with a
small barbed piece in the switch itself.
The switch is a single piece connected to a long square rod that does the actual switching.
I decided going the heavy handed approach and grabbed a locking plier. Lock it around the switch tightly and just leverage it down,
as if to break it off.
(
Don't forget to put some protective layers around the plastic switch or you will scratch it up.)
I had the head at a 45° angle at some point and then it just popped off.
Do not twist it around. It will
round off the square rod and make for a sloppy feeling switch.
The barbed piece will have popped out and you can use a small screwdriver or a corkpuller to take it out entirely.
Clean and polish everything you want and put everything back together. Push the barbed piece in using a screwdriver of something similar and you're done.
My suggestion would be to compress the pump in its X-mode or to scratch something to make it clear where to put it. Then again, it probably doesn't matter where you put it as it is a square switch anyway.
Pictures:
Good luck!
P.s. I have a brand new HPX on the way and I will try repeating these steps on that one. See if the steps can be reproduced.
I can make a short video of it if people are interested.
