What was found
FUEL TANKS DEVELOPED 600 LB IMBALANCE AFTER BEING BALANCED. ENGINE USE WAS NEAR EQUAL BOTH SIDES AT 6.28 & 6.30, RESPECTIVELY. ACFT GROUNDED. VERIFIED ON ACFT ARRIVAL TANKS READ -NR 1, 4.40 & NR 2, 3.83. PERFORMED PORTION OF FIM 28-41, TASK 820 FQIS BITE PROCEDURE 28-41 TASK 801, & CDS BITE PROCEDURE 31-62 TASK 801. NO CURRENT STATUS. NO INFLT RELATED FAULTS & GROUND SELF TESTS SHOW PASS. PERFORMED CROSSFEED VALVE FUNCTIONAL TEST 28-22-00-730-802. TEST PASSES. IAW TASK 05-51-48-211-801 NO FUEL IMBALANCE EXCEEDANCE OCCURRED. NO HISTORY 30 DAYS.