As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A POST INSPECTION RUN-UP, THE RIGHT FUEL GAUGE NEEDLE WAS READING ERRATIC (FULL TO ZERO). INSPECTION OF THE FUEL INDICATION SYSTEM FOUND THE RT FUEL TANK SENDER BAD. REPLACEMENT OF THE SENDER UNIT HAS CORRECTED THIS PROBLEM FOR A SHORT TIME. THERE HAS BEEN A HIGH NUMBER OF SENDERS; BOTH LEFT AND RIGHT, REPLACED IN FLEET OF 53 CESSNA 172R''S SINCE THEIR ARRIVAL. (X)