Disassembly, Repair And Assembly Of Fuel Pump 2B9 - Piper Arrow IV Turbo Maintenance Manual

DISASSEMBLY, REPAIR AND ASSEMBLY OF FUEL PUMP.
Overhaul of the fuel pump is not recommended because of special tools needed. If overhaul is necessary,
the pump should be returned to:
However, some repairs may be accomplished as follows:
l. Replacement of shaft seal.
A. Separate the pump end assembly from the motor by removing the four machine screws. Note the
relationship of the pump and motor before separation.
B. The shaft seal is assembled with a light press fit into the insert. lt can be pried loose from the insert
without disassembly of the pump.
C. Check the shaft for burrs, scratches or any defects which might cause the seal to wear. Any defect
would be cause for pump replacement.
D. Position a new seal on the shaft and press into place.
E. Assemble the pump end assembly to the motor in the original position. Install the four machine
screws and safety.
2. Repair of the relief valve.
A. Remove the adjusting screw from the pump end assembly. Do not change the position of the jam
nut.
B. Remove the valve plunger and spring.
C. Inspect the valve seat, plunger and spring for condition and wear. If the valve seat is damaged, the
pump should be replaced.
D. Reassemble the plunger, spring, if installed, and adjusting screw to the pump.
E. Adjust the pump pressure as described in Adjustment of Electric Fuel Pump (Bench Test) or
Adjustment of Electric Fuel Pump (In Airplane).
ADJUSTMENT OF ELECTRIC FUEL PUMP. (Bench Test)
1. Ascertain that the pump is sufficiently lubricated to prevent damage if run dry for a period greater than
five minutes.
2. Connect the electric leads to a 14-volt DC power source.
3. Using a suitable container with the proper octane fuel, connect a fuel line from a container to the inlet
side of the pump.
4. Connect another line from the outlet side of the pump to a pressure gauge and bypass valve and back
to the container.
5. Run the pump with the bypass valve open until a steady flow of fuel is obtained. Then close the bypass
valve and check the pressure gauge for a proper reading of 26 to 29 psi, no flow. Do not keep the bypass valve
closed for more than one minute during pump operation and adjustment.
6. Loosen the locknut and turn the adjusting screw until there is a reading of 29 psi maximum, no flow,
on the gauge. Repeat Steps 5 and 6 until the proper pressure is obtained.
7. Disconnect the power source from the pump and lock the adjustment screw with the locknut. Remove
the fuel lines from the pump.
PIPER AIRCRAFT
PA-28RT-201 / 201T
MAINTENANCE MANUAL
The Weldon Tool Company
3000 Woodhill Road
Cleveland, Ohio 44104
2B9
28-20-16
Page 28-14
Revised: August 17, 1982