Table 3-1. Operator Troubleshooting Chart - continued

TM 5-4210-224-14&P

Table 3-1. Operator Troubleshooting Chart (Continued).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

3. FIRE PUMP WILL NOT PRIME OR LOSES PRIME (Continued).

Step 6. Check if primer was operated long enough.

NOTE

Do not run primer longer than 30 seconds. Open discharge valve slowly during completion of

prime.

Follow proper priming procedures (paragraph 2-16). Do not release primer control before assurance of

complete prime.

Step 7. Check that suction hose has been laid with a continuous slope down to water supply and has no

air traps.

Adjust suction hose as required. Repeat priming may be necessary to eliminate air pocket in

Step 8. Check if pump pressure is too low when nozzle is o ened.

Reprime pump and maintain higher pump pressure while opening discharge valve slowly (paragraph 2-

16).

4. INSUFFICIENT FIRE PUMP CAPACITY.

Step 1. Check for insufficient engine power.

Adjust engine throttle control. If still insufficient notify next higher level of maintenance.

Step 2. Check is pressure relief valve is set at too low a pressure.

Adjust pressure relief valve control to desired pressure.

5. EXCESSIVE ENGINE SPEED IS REQUIRED TO ACHIEVE REQUIRED FIRE PUMP PRESSURE OR

CAPACITY.

Step 1. Check for blockage of suction hose strainer.

Remove obstruction from strainer. Do not allow suction hose strainer to reset on bottom of water

supply, but keep it at least two feet (0.61m) below the surface of the water.

Step 2. Check for defective suction hose by trying a different suction hose on the same pump test mode.

The inner liner of the first suction hose may be collapsed in which case the defective hose should be

replaced.

Step 3. Check for high vacuum and rough operation caused by higher than normal lift or suction hose

too small.

A larger suction hose should be used.

3-4