SDR 99ZZZX52

Service difficulty report · Pump

Difficulty date
September 21, 1998
Submitted
March 26, 2000
Operation
General aviation
Engine
Cont GTSIO520L
Part
Pump
Part number
632623A23
Condition
Mismanufactured
Location
Oil System
Component
632623A22
Stage of operation
IN
Nature of condition
W
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

NEW TCM OIL PUMP HOUSING WAS PURCHASED FORM LOCAL AVIALL DISTRIBUTION BRANCH. UPON VISUAL INSPECTION OF PART PRIOR TO ASSY AND DIMENSIONAL CHECKS, NOTED THE CHAMBER DEPTH WAS BELOW MINIMUM SPECS PER MANUAL. FURTHER INVESTIGATION REVEALED MACHINING STEP WAS NOT CLEANED UP IN THE RADIUS. THIS CAUSES THE GEARS TO SIT UP HIGHER IN THE CHAMBER BORE AND WHEN THE SCAVENGE PUMP HOUSING IS INSTALLED OVER THE TOP, THERE IS NO END CLEARANCE CAUSING GEARS TO BIND UP. SUBMITTER RECOMMENDED COMPLETE VISUAL AND DIMENSIONAL CHECK ON ALL HOUSINGS PRIOR TO ASSY. (THIS IS THE SECOND HOUSING FOUND, WITH THESE CIRCUMSTANCES).