Piper SENECA II Service Manual page 521

9-19a. FUEL SYSTEM LEAKAGE INSPECTION
CAUTION: THE FUEL CELLS AND/OR TANKS MAY BE DAMAGED IF MORE THAN 1.5 PSI
PRESSURE IS INTRODUCED INTO THE SYSTEM.
The following procedures are provided for troubleshooting purposes only.
A. Setup
1. Ensure the fuel lines and components of the fuel system are readily accessible.
2. Defuel the airplane prior to performing any of the following tests.
3. A test fixture containing the following features is required to perform this test:
(See Figure 9-2a to fabricate.)
4. Ensure appropriate caps are available for closing open lines and vents.
5. Apply bubble testing liquid (P/N 279-246) to surfaces being checked for leaks.
B. Fuel Tank Leak Test
The following procedure, as written, tests both fuel tanks (and the optional fuel cell) as a unit when
installed in the airplane.
NOTE: If the optional fuel cell is removed from the airplane, test per paragraph 9-26.
NOTE: The metal fuel tanks can be tested individually by capping all outlets from the tank being
tested. (Testing either inboard tank will require fabrication of an adapter incorporating a 5
psi gauge and a shut-off valve which can be substituted for the fuel filler test cap and
attached to the tank interconnect fitting.)
1. Cap all fuel vent outlets on the wing and all fuel lines exiting from the tank.
2. Verify fuel sump drain valves (located underneath the LH and RH wings) are in the closed
position.
3. On the test fixture, check that the following valves are in the OFF position (see Figure 9-2a):
- #1 and #2 main airs supply shut-off valves
- #3 Manometer needle valve
- #4 Main air supply needle valve
- Shut-off valve on each fuel filler test cap
- Both flow meter shut off valves
4. Install test unit fuel cap at the fuel filler port in the wing(s) being tested.
5. Connect shop air to test fixture.
IX - FUEL SYSTEM
PIPER SENECA II SERVICE MANUAL
- Two air filters
- Pressure Regulator
- Two fuel filler test caps each incorporating a 5 psi gauge and a shut-off valve
- Main pressure gauge (0 - 5 psi; marked red above 1.5 psi)
- Two main air supply needle valve
- Manometer
- Manometer needle valve
- Flow meter (0.0 - 0.5 SCFH)
- Two flow meter shut-off valves
2D14
(PIR-PPS60049-4, Rev. B.)
01/01/09