FIFTH WEEEL DOESN'T LIFT (Cont)

TM 9-2320-285-24-2

3-40. FIFTH WHEEL HYDRAULIC SYSTEM TROUBLESHOOTING (CONT)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

1. FIFTH WEEEL DOESN'T LIFT (Cont)

d. If pressure gages indicate approximately equal pressure, fifth wheel hydraulic control valve is

defective; repair or replace (para 3-42c)

e. If both pressure gages indicate zero psi, proceed to step 3 below.

WARNING

Keep clear of fifth wheel boom moving parts to prevent serious injury or death.

Step 3. Have assistant operate PTO control; watch movement of power take-off shift lever.

a. If shift lever does not move fully to "power take-off engaged" position when PTO control is pulled out

fully, adjust or replace PTO control cable (para 3-42b).

b. If shift lever moves fully to "power take-off engaged" position when PTO control is pulled out fully,

proceed to step 4 below.

Step 4. Check hydraulic pump key for sheared condition.

a. If sheared, replace (para 3-42a).

b. If not sheared, proceed to step 5 below.

Step 5. Start vehicle engine and watch power take-off output shaft for rotation.

a. If power take-off output shaft rotates, repair or replace fifth wheel hydraulic pump (para 3-42a).

b. If power take-off output shaft does not rotate, repair or replace power take-off (para 3-42b). If

malfunction is not corrected, notify general support maintenance (transmission may require overhaul).

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