Balloon Pump

Two variations in the same print; The double-acting piston is working, but there’s too much pressure loss. I think it might be because of the rough surface finish. The single acting piston with directional seal is working better. Assemblies are per exploded views and object list. Materials are PLA and TPU. Remove the model at the pause. I had a slicer glitch for top layer set to zero on the connecting rod. Note: only use cap seal with double-acting piston or top of cylinder will be dead headed. Add a little grease to improve operation. I’d really appreciate any feedback.