Manifold Pressure Gauge Packed with Trash

Milk Man

As some of you may remember, my Arrow was in a Hangar for 10 years until my purchase in March. Four months later, she had a fresh Annual and flew Again. I have put about 12 hours on the Tach since then. Recently I noticed the Manifold Pressure Gauge was starting to Lag and Stick until last week it stuck on 16" and wouldn't move, even with the engine off where it should indicate standard pressure of 30" or so. I decided to remove the Instrument to send it off for repair. After I got it out of the plane and turned it over, I noticed that the fitting on the back was packed solid with Trash! I am assuming that it is corrosion from the Aluminum AN816 Fitting that connects to the Copper Tube that runs to the back of the Intake. I assume that this was brought on from the 10 years in the Hanger. I removed the fitting and found more Trash just inside the Gauge. Once the Trash was removed the gauge indicated the proper 30" of Manifold Pressure. I ordered a new Aluminum AN816 -3 fitting and after I receive it, I will put It back together and reinstall and test it in action. Just another issue you need to watch out for on a bird that has sat for a long time. I have attatched some pics.

Milk Man

I ended up sending the gauge in to have it cleaned and rehabbed. There was still some corrosion in it that I couldn't see. It works great now!