Leveling jacks

I agree, clean them and then use some 5606 or other transmission fluid and lube them heavy. Then run the jacks up /down a few times. Then wipe them with a clean cloth to get the excess fluid off. Install the new taper springs. Might take a few time with the spray down with fluid and cycle them and wipe them clean, and you should not have a hanging jack. Our last from 1999 to 2018 when we trade it for a newer model using this method. I work 23+ years with aircraft and this spray down and clean every time they flew and when they no longer worked the landing gear was torn down and new O-rings were installed. Then start over again. The seal need some type of lube. I am sure that newer jacks should have a newer type seal so maybe they have improve on the lube system.