Sooner or later you’ll be faced with repairing or replacing an original-equipment engine or system gauge. It is impressive that many OEM manifold pressure, fuel flow, pressure and other gauges produced more than 60 years ago continue to function today.
But without regular maintenance, their accuracy could be compromised. One option is to upgrade to an all-in-one electronic engine display, but that requires a sizable investment that might be questionable for basic aircraft.