If you ever have an air jack that is slow to retract or won't retract you should definitely disassemble them to see what is going on. A few years ago one of my air jacks started to retract very slowly and after a short while it got stuck in the down position. When I took the jack out and inspected it I was quite surprised to see what was causing it. One of the seals had twisted several times and got pushed over the piston (see pictures). Luckily the parts are easy to get and they are easy to repair. You can get a seal kit from the manufacture JLSairjacks.com in the UK or if you are in the US the XRP.com is the US distributor. The seal kit cost about $15 per jack. I only replace the seals in the jack that had the issue and I never had an issue with the other two jacks.
I hope this information will be helpful to anyone who's air jacks start to stick.
Charley
