G1K try Marlin P. Jones & Assoc. Inc. They are a surplus warehouse for electronics and tools. I've had great success with them in the past. On line at http://www.mpja.com
Pete, If its the part I think it is...its part of the unloading syst.
If the head unloading valve or the unloader valve are bad then air will leak out all the time.
Otherwise the only time air will vent out is when the unloader switches from an unloaded state to a loaded state. The air must go...
I have been using them both at home and at work. I love the fact that you get lots of light and very little heat output to get burned on. I have had several times where I used a small voltage inverter (12volt dc to 115volt ac) to use my light when no 115volt outlet was accessible. What the...