Originally Posted by
Artmo
My problem is not getting the block in, but one of the springs keeps popping out.
See
THIS video showing the dismantling of the latch mechanism. The sliding plate seems to be installed with the springs in place; these are displaced to install the retaining screws. The hex screws ("grub" screws) do not need to be removed. Notice at about 3:20 that the retaining screws are loosened slightly. This is because if they are tight the handlepost may be able to be locked in place, but the springs will not be able to retract the plate and the only way to unlock the latch is to remove the hinge pin... not something you want to do.
I have a Dahon Mu XL that I've had since 2006. The handlepost is like the OP's and I've replaced the white plastic block several times over the course of over 12,000 miles.
FWIW, I have enjoyed this bike the entire time I've owned it. I've been using it as my "winter" bike since I got a Tern Verge S11i in 2013, and the salt here in Chicago has finally destroyed the frame. It does not give me any joy to retire the bike; I used it hard and it did its job well.
The Mu XL "Winter" about 5 years ago. It was already pretty well thrashed by then. Notice the cracked seat tube.