I don't think there is a check valve in the jack ass'y, just a seal at the top. The check valve would be in the pumping unit and valve body. What problem are you having?? Or do you just want to dis-assemble it.
I guess it isnt a check valve it looks like a flow restrictor it is screwed into the bottom every once in awhile the car would come down slow both on auto and on manual lower there was some gunk in the flow restrictor so far it is coming down normal
