TM 5-4310-393-14
3-17. INSTRUMENTS.
This task covers: A. Inspect B. Replace
Tools:
Materials/Parts:
Tool Kit, General Mechanic's Set
Tape, Teflon NSN 8030-00-889-3534
Detergent, Non-ionic NSN 7930-00-282-9699
Distilled Water NSN 6810-00-297-9540
Equipment Conditions:
Equipment secured
System Purged of Pressure
A.
Inspect.
1.
Inspecting the Instruments for Damage.
a.
Inspect all system pressure gauges and hourmeters for physical damage such as broken or cracked lenses,
leaking fittings and so forth. If gauges are suspected to be inaccurate, they should be calibrated. Refer to General
Support Maintenance.
B.
Replace.
1.
Replacing the Gauges.
a.
Replace gauges by unscrewing the pressure line fitting on the back of the gauge, then unscrewing the bezel nuts
on the back of the gauge, which hold it in its mounting hole. Replace in reverse order of removal. Soap test pressure
connections using non-ionic detergent solution. Make sure to keep any foreign matter from entering the pressure tubing.
2.
Replacing the Hourmeters.
a.
Hourmeters are provided to record hours of operation for the compressor section and the engine section.
Each hourmeter is mounted in a bracket having two mounting positions. By design the hourmeters will not record when
placed in with the face out of a horizontal position by more than 45 For operation use the HOURMETER ON mounting
hole in the bracket. For transportation of the unit, mount the hourmeter in the HOURMETER OFF position. To relocate
the hourmeter from one position to the other:
1.
Unscrew the large plastic mounting nut at the back of the bracket and remove the hourmeter.
2.
Place the hourmeter in the appropriate mounting hole and re-secure the nut to hold the hourmeter in place.
3-30