Pc Air Filter - Removal
Pc Air Filter - Cleaning and Inspection
Pc Air Filter - Installation
Fuel Nozzle - Removal
Fuel Nozzle - Cleaning
Fuel Nozzle - Inspection
Fuel Nozzle - Installation
6-1. FUEL SYSTEM MAINTENANCE PROCEDURES
Visually inspect all subassemblies and accessories removed from the engines fuel system, Check for loose or mis-
sing parts. Note any damage or excessive wear. Repair damaged parts where possible. Replace damaged parts that
cannot be repaired. Disassembly procedures provided enable required cleaning, inspection, repair or replacement.
6-2. Bleeding the Fuel System. Maintenance of the fuel system can result in air entrapment in the fuel lines and subse-
quent false starts. Following maintenance, purge the air from the fuel system as follows:
a. Disconnect the input lead to the ignition exciter or pull the IGN ENG circuit breaker (refer to TM
55-1520-235-10, TM 55-1520-228-20).
b. Disconnect the fuel hose at the fuel nozzle; place the open end of the hose in a bucket.
c. Move the twist grip to the IDLE detent and motor the engine until a solid stream of fuel flows from the discon-
nected hose. (Use APU if available.)
d. Reconnect the fuel hose to the fuel nozzle and input lead to the ignition exciter or reset IGN ENG circuit breaker.
on governor to fuel control) is removed or disturbed during maintenance, check the control air tubing for leaks as fol-
a. Disconnect the pressure sensing (PC) line from the pressure probe elbow in the diffuser scroll.
c. Use a liquid soap solution (item 1, table 2-1) to check the air tubes for leakage. Cover and parting surfaces on
the fuel control and governor which produce a slight bubbling of the soap solution do not represent a leak of sufficient
magnitude to warrant concern. These leaks were present during original calibration and were compensated for at that
d. Reduce the pressure to 20-22 psi (0.14-1.54 kg/sq cm) and check the governor diaphragm for leakage. No leak-
age is acceptable. If leakage is noted from the governor diaphragm, remove the safety wire from the screws, back off
screws and then torque to 8-11 inch lbs. Let screws rest for 20 minutes and retorque to same valve. If after this is com-
pleted, the governor diaphragm still leaks, replace governor.
e. Reconnect the PC tube. Tighten coupling nuts to 80-120 in. lbs. Hold the PC filter while tightening the coupling
nut. During aircraft run up, use the soap solution to verify no leakage around the reconnected Pc line prior to flight.
Rinse water solution from the engine after the check is completed.