TM 5-4320-306-10
Table 3-1. Operator/Crew Troubleshooting - Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
8. PUMP FAILS TO PRIME
Step 1. Check that pump volute is filled with liquid to bottom of suction port.
Remove dust cap from priming port on pump body and fill pump volute (para 2-6. c. ). Replace
dust cap.
Step 2. Check that engine speed is correct for the specific gravity of liquid being pumped. Refer to pump
performance data plate.
Adjust MANUAL THROTTLE CONTROL until engine is running at correct speed (para 2-6. g. ).
Step 3. Check for restrictions in flow through suction and discharge assemblies and hoses.
Perform the checks and services of table 2-2, item 8, and clean away debris. Replace severely
damaged or restricted hoses.
Step 4. Check the suction assembly components and connections for leaks. Check suction hose connection,
gate valve, spool, strainer, gaskets, and the connection between the strainer and pump assemblies
(para 2-6.e.). Check that locking lever securely holds strainer in place.
a. Tighten hose connection.
b. Tighten strainer locking lever.
c. For any other leaks found, notify organizational maintenance.
Step 5. Check for clogged suction strainer or suction hose.
Perform the checks and services of table 2-2, item 6, and clean away debris from suction strainer
and hose. Replace severely damaged or restricted hoses.
Step 6. Check for excessive suction lift.
Move centrifugal pump unit closer to source of liquid.
Step 7. Check the discharge check valve for a defective valve spring.
If the valve spring does not hold the valve closed long enough to establish prime, hold the valve
closed until the prime is established.
3-8
