Hi Bob, I purchased SimworX Pro GT 3.1 pedals used off of the iRacing forums back in December 2023. Original owner took great care of them and was very friendly. I did my due diligence too and watched all of SRG's review, researched "pneumatics", and came to the conclusion that there must be no liquid in them. Which was the biggest reason I bought them.View attachment 705379
The cylinder used on the throttle is pneumatic, you can see the bolts with the vents at top and bottom of the cylinder.
The cylinder on the brake has a vented bolt at the top of the cylinder and a sealed bolt at the bottom so I would assume the cylinder is now holding a fluid of some type.