I never had one apart, but I remember reading that they operate with an expanding rubber bladder that presses against the rod. More pressure, rubber expands more, rod moves out more. For that reason, I would not use a lubricant that could affect the rubber.
Originally Posted by oldnslow
Spend some coin and get a quality gauge.
I bought a Longacre 50356, 0-60 psi with angle chuck. Not cheap, not a toy and not a single regret. For starters, when I press that chuck on, it seats!...without the usual hissing sound of escaping air. It can be user calibrated and the 9V battery is user replaceable. Accurate to 0.3% or 0.2 psi at full scale.
Last edited by GlobalRider; 01-10-2013 at 02:33 AM.