Section VI. TROUBLESHOOTING - TM-5-4320-234-120035

M--Monthly

Q--Quarterly

Interval and

ITEM TO BE INSPECTED

Sequence No.

PROCEDURE

COOLING SYSTEM

With the engine cold, open the radiator access cover on top the engine housing and remove the radiator

cap. If the coolant level is low, check for coolant leaks. Some leaks are evident only when the engine is

hot, and the coolant system is fully pressurized.

FAN BELT

Inspect the fan belt for glazing, cracks, or other wear. The belt must deflect 3/4 to 1 inch with thumb

pressure at midpoint of the longest belt span. Adjust belt as described in paragraph 4-31.

HOSES AND PIPING

Inspect fuel lines, fuel pump, coolant hoses, water pump, and pump gage lines for leakage, Tighten fuel

line fittings as necessary. Replace leaking parts.

PUMP

Inspect pump suction and discharge assemblies for loose mounting or damage. Check that the pump is

firmly mounted to the chassis. The pump must be aligned carefully with the engine. Align and tighten a

loose pump.

CHASSIS

Inspect engine shrouds and chassis frame for cracks or damage. If damage is extensive, refer to direct

support maintenance for repair.

TIRES

Fill tires to 40-psi air pressure and inspect them for cuts, bruises or blisters. Tire repair is described in

paragraph 4-51.

TACHOMETER DRIVE

Turn grease cup on tachometer drive clockwise two full turns to provide grease to the gear teeth. When

the grease cup is turned down all the way, refill it with automotive grease and reinstall it. Add grease at

grease fitting.

RADIO SUPPRESSION EQUIPMENT.

Inspect spark plug cable shields for wear or breaks. Replace if necessary. Tighten engine ground

straps as required.

MAGNETO ADJUSTMENT

Check magneto breaker point gap. Adjust magneto breaker point gap to 0.015 inch (para 4-35).

STARTING MOTOR OPERATION

Follow starting procedure described in paragraph 2-3. While starting motor is engaged, listen for

unusual noises or sluggish operation. Replace if defective (para 4-42).

ALTERNATOR OPERATION

Note the alternator charging rate indicated on the ammeter. For the first few minutes after the engine is

started, the charging rate should be high, but it should level off to a lower value within 10 minutes, if

batteries were properly charged at startup. If the alternator or regulator is visibly damaged. replace as

required (para 4-38 and 4-39).

GOVERNOR TEST

Clean governor linkage and lubricate with light engine oil. With the engine running at operating

temperature, push throttle control all the way in and note engine speed on tachometer. Maximum no-

load governed speed must not exceed 2450 rpm. Governor adjustment is described in paragraph 4-27.

Section VI. TROUBLESHOOTING

4-12. General

c. Table 4-2 lists the common malfunctions that you

a. This section contains troubleshooting or

may find during the operation or maintenance of Pump,

Centrifugal or its components. You should perform the

malfunction information and tests for locating and

tests/inspections and corrective actions in the order

correcting most of the troubles which may develop in the

listed.

Pump, Centrifugal. Each malfunction or trouble

symptom for an individual component, unit, or system is

4-13. Organizational Maintenance Troubleshooting

followed by a list of tests or inspections necessary for

Chart

you to determine probable causes and suggested

corrective actions for you to remedy the malfunction.

Refer to table 4-2 for troubleshooting which is allocated

b. This manual cannot list all possible malfunctions

to organizational maintenance levels.

that may occur or all tests or inspections, and corrective

NOTE

actions. If a malfunction is not listed, or is not corrected

by listed corrective actions, you should notify higher

Before you use this table, be sure you have

level maintenance.

performed all applicable operating checks.

4-5