FIRE PUMP - Continued
(2) Attach six in suction hoses to suction adapter. Make sure suction screen is well below water surface.
(3) Start truck and engage fire pump. Fire pump should be primed within 30 seconds.
(4) If fire pump will not prime, shutdown pump and main engine immediately and refer to test procedures in b.
It will be necessary to remove suction tee and discharge elbow (see TM 5-4210-220-12) from truck if b.
Vacuum Testing is required
(1) Apply gasket eliminator (item 14, Appendix B) to the suction (wearing ring) and discharge flanges.
(2) Secure the discharge blanking plate (6, Appendix D) to the discharge flange and secure the suction blanking
tool (7, Appendix D) to the (wearing ring) using the pump fasteners.
(3) Attach priming suction pipe to suction blanking tool (7, Appendix D) and priming valve
(4) Attach vacuum gage to suction blanking tool (7, Appendix D).
(5) Start truck and engage PTO. Run engine at approximately 1200 rpm while watching vacuum gage.
(6) Stop the pump once 24 in. Hg is obtained. The fire pump should maintain this vacuum for at least 15
seconds. If the fire pump will not hold this vacuum, the fire pump has a leak Pressure test should be carried
out as detailed in c. following. If pump maintains 24 in. Hg for 15 seconds proceed to step 9.
(7) If the pump does not reach a vacuum of 24 in. Hg, but will hold lower vacuum, the priming system is at fault.
Check the following: Make sure fiber driving wheel is engaged with pump pulley and spins without slipping.
Make sure primer reservoir is filled with antifreeze (item 2, Appendix B). Examine the primer seal drain hole
for evidence of leakage. If leakage is found, replace seal as detailed in (para. 2-13.7).
(8) If the pump does not reach a vacuum of 24 in. Hg, and will not maintain what vacuum it does create, there is
a leak and possibly a fault in the priming system. Pressure test fire pump as detailed in c. following.
(9) Once fire pump tests have been completed and are within specifications, remove discharge blanking plate (6,
Appendix D) and suction blanking tool (7, Appendix D).
(10) Reinstall discharge elbow and suction tee (see TM 5-4210-220-12).