—CAUTION—
Do not remove the buffer spring and valve from the plunger assembly.
Do not tamper with seal at center of mounting bracket at side of pump
as it retains the dry gas which surrounds the electric system in the
upper portion of the pump.
9-31. CLEANING, INSPECTION AND REPAIR OF FUEL PUMP.
a. Clean all parts with acetone or a suitable dry type solvent. If plunger assembly does not come clean or
there are any rough spots, polish gently with crocus cloth.
b. Inspect the pump for the following:
1. Check the filter screen for damage or distortion.
2. Gently touch the cup valve and check for freedom of movement. Do not disassemble.
3. Shake the plunger assembly and listen for clicks to indicate valve action.
4. Check the condition of the O-ring.
5. Check the condition of the cover gasket and plunger spring cup gasket.
c. Repair of the pump is limited to replacement of parts found defective during inspection.
9-32 . RESISTANCE CHECK (PLUNGER TYPE PUMP). To check the resistance of the pump, connect an
ohmmeter to the lead wire of the pump and the pump body. A reading of 4.87 to 6.4 ohms for a 12-volt pump
should be obtained.
C349
7. O-RING
8. CUP VALVE
9. SPRING
10. PLUNGER
11. PLUNGER TUBE
12. PUMP BODY
1. COVER
2. COVER GASKET
3. MAGNET
4. FILTER SCREEN
5. RETAINER
6. WASHER
Figure 9-7 Plunger Fuel Pump
PIPER AIRCRAFT
PA-28-161 CADET
AIRPLANE MAINTENANCE MANUAL
Issued: FEBRUARY. 28, 1989
FUEL SYSTEM
2A21
