Volvo

I replaced it myself from another semi at a scrap yard. without a load on the hitch, what would the rear air bags look like when they are properly inflated? would they be partially up the plastic sleeve or resting on the bottom? when weight is added to the hitch, will they slide up the sleeve?

To get you close to the area i would set the lever at 12" from the air bag support on the bottom of the air bag to the bottom side of the frame. to get the right numbers i would call a volvo dealer to get the right specs. but that will get you close. the air bags inflated should show about half of the bottom of the plastic (bottom side of the air bag)piece. if they are resting on the bottom they will be deflated. they may go down a little and then go back up the bag to where it is ad ed.