9-10. REPLACEMENT OF FITTINGS.
—NOTE—
Defueling of airplane may be required for union and/or tubing
replacement.
continues to leak after being tightened it must be repaired.
b. The recommended repair is to remove the leaking union and replace it using a standard AN fitting as
outlined in AC 43. 13-1 A paragraph 392. This will require cutting off the swaged ferrule and adding a short
length of tubing.
c. If a replacement tube and union purchased from Piper is being used, the ferrule is pre-swaged onto the
tube. Install the pre-fabricated tube as follows:
1. Apply a thread lube as recommended in Step d of paragraph 9-9 to the threads of the union.
2. Carefully align the tube into the union and snug up the nut using a wrench.
3. Then using the wrench, tighten the nut one to two flats (1/ 6 to 1/ 3 of a turn).
d. If a repair is being made using Parker-Hannifin unions and tubes without pre-swaged ferrules they should
be installed as follows:
1. Cut off the tubing at a convenient location back from the fitting.
2. De-burr the end of the tube and prepare a short length of tube to splice into the line.
3. Screw the nut and ferrule onto the union until solidly finger tight.
4. Insert the tubes into the unions, being careful to insure proper straight alignment of the tubing and
union.
5. Using a tubing wrench tighten the nut one and one-quarter (1-1/4) turns.
C108
1/4" OD
TUBING
3/8"OD
TUBING
.08" TO .11"
.12" TO .17"
Figure 9-2. Tolerances. Union Nut and Tubing
PIPER AIRCRAFT
PA-28-161 CADET
AIRPLANE MAINTENANCE MANUAL
Issued: FEBRUARY. 28, 1989
FUEL SYSTEM
2A14