TM 5-3805-255-14
0099
TESTING CONTINUED
NOTE
Do not wipe tip with finger as this will tend to draw fuel present in sac hole through orifices
and falsely indicate a leak and rejection of a good valve. Touch a finger or hold a wiper
lightly against tip of valve. Leakage at seat may be caused by dirt or foreign material,
carbon, or gum deposits at seat area or excessive wear of seat. If seat is worn, it may be
refinished with precision grinding equipment.
5. STEM LEAKAGE: Bring pressure on nozzle to 1,500 psi (10,350 kPa). If there is any leakage from return,
collect it. To conserve time, nozzle may be in inverted position. Maximum allowable leakage is one cc in one
minute at this pressure.
NOTE
Excessive leakage at this point can be caused by scratches or poor sealing at flat surfaces
of nozzle body, intermediate plate or valve body. If this possibility has been already
eliminated, there is excessive clearance between valve stem and body. This condition
necessitates replacement of nozzle valve.
END OF TASK
END OF WORK PACKAGE
0099-2