6-NFR DISTRIBUTING VALVE SAFETY VALVE
This task covers:
Tool kit SC4940-97-CL-E12
Antiseize tape (Item 35, Appendix B)
· Whenever the 6-NFR distributing valve safety valve is removed and installed for any reason, a
stationary locomotive airbrake test (para 2-9) must be performed to check that the 6-NFR distributing
safety valve functions properly in the brake equipment arrangement. Failure to perform test may
result in injury to personnel.
· Make sure air is drained before removal of the 6-NFR distributing valve safety valve. Residual air
may escape and cause injury to personnel.
When removing or repairing brake valves or components, check air lines and pipes for corrosion,
breaks, splits, or loose connections. Repair of air lines and piping consists of replacing defective
pipes, lines, and connections. Refer to TM 55-2210-224-24P for identification of piping.
Start locomotive and let air pressure build up.
Move automatic brake valve handle to FULL APPLICATION.
Monitor brake cylinder air pressure gage and move automatic brake valve handle into the service zone until brake
cylinder pressure rises to 67 psi (462 kPa). Between 67 and 68 psi (462 and 469 kPa), the 6-NFR distributing
valve safety valve should blow. If the safety valve is adjusted incorrectly, refer to steps 7 thru 9.