Table 2-1. Preventive Maintenance Checks and Services
Items To Be
Check high temperature water control (TM 55-1905-223-10):
a. Remove sensing unit from water passage.
b. The opening of the circuit can be checked against a thermometer, while immersed in water,
as the water is heated to activate temperature control.
The warning horn should sound at about 200 (93 ).
Check low lube oil pressure protective device (TM 55-1905-223-10):
a. With engine shut down, remove protective device from engine block and reconnect the wire.
b. With shutoff valve in oil pressure line open and bleed valve closed, operate engine at rated
speed and no load.
Open bleed valve and purge air from system.
d. Close bleed valve and record oil pressure on instrument panel oil pressure gauge. Close
e. Observe the instrument panel oil pressure gauge and slowly open bleed valve until
protective device sounds the warning horn.
Sensing unit should activate when pressure is lowered below operating level.
Replace water pump every 24 months or every 2000 hours,
whichever comes first.