On Monday, June 11, 2018 at 4:20:38 PM UTC-4, Bob Kuykendall wrote:
On Monday, June 11, 2018 at 11:54:14 AM UTC-7, wrote:
Irrelevant.

Fully relevant. Engineers were surprised to discover that under certain conditions of wear and abuse, the PCU would produce outputs that were exactly the opposite of those commensurate with the input conditions.

I've disassembled three or four different types of gas spring (each of my gliders has two), and I'm pretty sure that there are possible failure modes in which the unit resists opening instead of assisting it. They're probably not common failures, but I'd bet solidly against impossible.

Bob K.

Just catching up with this thread now and finding the very belittling response by Steve to my suggestion deeply insulting! When I said that I understand the inner workings of a gas spring and that I designed similar devices, than that is fact based. We carefully took apart several different gas springs and then designed a gigantic version of it - the type that holds down the tag-axle of a concrete mixer truck! It had some other functionalities built in but I will not get into that.
Steve is correct in describing the type of spring he took apart and that the kind of behavior as described by the original poster with those types is unlikely but is that the only type? How does he know that this is the type used in that particular trailer?
As other posters mentioned above, the sniping and 'I know it all and the rest of you are stupid for suggesting otherwise' is highly unprofessional and discouraging towards posting anything. The purpose of this and similar fora is to exchange ideas and help each other out in solving issues we have with our equipment; not to pile-drive others.
N'uff said!
Auxvache, good luck in getting the trailer opened up again and please keep us posted as to what you find out.
Uli
'AS'