Citroen Jumper Front Shock

[moizeau]

I've got the front shock assy off, the top bearing is seized so that needs a new one. Although the shock has resistance, extending the strut takes more effort than contracting it. Bearing in mind that most of the work is actually getting it out I'm going to advise the lad to replace both shocks and the protection.
The question is, going from the part numbers there are 2 options, gas or oil filled. I think the one's on it are oil because they don't extend by themselves, or they're flatish.
Haven't played with shocks for donkeys so could someone shed some light please?
Cheers