GM-GMC: Oil Pressure Gauge, oil pressure gauge, chevy pickup truck

Question
I own a 1987 Chevy Pickup truck all original parts 70,000 miles.  The oil pressure gauge needle is stuck all the way to the right PAST MAX.  I had a mechanic tell me to tap on the face of gauge with my fingers but that did not work.  The truck is not losing oil at this time.  I would fill better if the darn gauge worked properly.

Any advice on how to fix this problem.

Answer
I suspect that it is the gauge that has malfunctioned.  I had the same thing happen to the water temperature gauge on my 1983 G-20.

The only solution is to replace the gauge.  Try an auto salvage yard or go to www.car-part.com to search nationally for the gauge.