What was found
RADAR FAILURE WARNING ON CLIMB-OUT ANTENNA FAIL QUIT SWEEPING. CHECKED ALL WIRING FROM ANT TO R/T, BOTH POINT TO POINT, WIRE AND TO GND. ALL CKS GOOD, R/T MESSAGE ANNUNCIATED BRIEFLY. REMOVED AND REPLACED R/T FOUND ANTENNA WAVE GUIDE O-RING DETERIORATED REPLACED SAME. FOUND INDICATOR LEFT BUTTON INOP. REMOVED AND REPLACED IND A/C CLEARED FOR TEST FLIGHT PER MOCC.