COOLING SYSTEM TROUBLESHOOTING

TM 3930-638-24&P

1 2 - 1 1 . EXHAUST SYSTEM TROUBLESHOOTING (cont)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

2. EXCESSIVE EXHAUST SMOKE

Check if muffler requires cleaning.

NOTE

If problem is not corrected, notify direct support maintenance.

12-12. COOLING SYSTEM TROUBLESHOOTING

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

ENGINE OVERHEATS

Step 1. Check fan belt for proper tension.

Depress fan belt midway between fan pulley and crankshaft pulley.

Fan belt should be deflected approximately 1/2 inch.

a. If fan belt does not deflect 1/2 inch approximately, adjust it (para 2-17f)

b. If fan belt deflects 1/2 inch approximately, proceed to step 2 below.

Inspect fan belt for damage, wear, oil covered, or riding deeply in pulley groove.

Step 2.

a. If any of the above conditions are observed, replace fan belt (para 2-17f).

b. If none of the above conditions are observed, proceed to step 3 below

Step 3. With engine idling, remove radiator cap and observe coolant to see if it moves indicating water pump is

operating.

a. If coolant movement is not observed, replace water pump (para 2-17e).

b. If coolant movement is observed. proceed to step 4 below.

Step 4. Check radiator and hoses for leakage or damage.

a. If radiator and/or hoses are leaking or damaged, replace (para 2-17C and 2-17b, respectively).

b. If radiator and hoses are okay, proceed to step 5 below.

Step 5. Check fan blade assembly for damage.

a. If fan blade assembly is damaged, replace (para 2-17 f).

b. If fan blade assembly checks okay, proceed to step 6 below.