Table 4-2. Manometer Troubleshooting Chart

TM 5-6640-214-14

b. Troubleshooting. The operator should be guided by the following chart (table 4-2) in diagnosing and correcting

operating difficulties.

Table 4-2. Manometer Troubleshooting Chart

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

1. NO PRESSURE (READING)

Step 1. Check if pressure is not being applied to either or both sides

of the instrument.

Check for plugged or leaking pressure lines. Make applicable

correction.

Step 2. Inspect atmospheric pressure connection for proper venting to

atmosphere.

Make applicable correction to ensure proper venting.

Step 3. Check for foreign particles in internal passages of the meter

which are blocking the flow.

Remove mercury from meter and check internal passages for

foreign particles. Clean instrument as required.

2. HIGH OR LOW PRESSURE READING

Step 1. Check for leaks or obstructions.

Locate leaks or obstructions, make applicable connections.

Step 2. Check tubing and/or mercury for foreign matter.

Disassemble and clean instrument, replace mercury.

Step 3. Check for improper zero setting.

Check zero setting. Make proper adjustment.

4-5. VACUUM PUMP.

a. Lubrication.

(1) Motor. Lubricate monthly with engine crankcase lubricating oil.

4-23