FIFTH WHEEL HYDRAULIC SYSTEM TROUBLESHOOTING

TM 9-2320-285-24-1

2-76. FIFTH WHEEL HYDRAULIC SYSTEM TROUBLESHOOTING

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

1. FIFTH WHEEL DOESN'T LIFT

Step 1.

Check that engine is running, PTO control is pulled up and power take-off engaged, gear shift

control lever is in neutral (N) position, 5th WHEEL control lever is pulled back fully, and load weight

does not exceed tractor's 70,000 pound lifting capacity.

a. If above conditions are not met, refer to TM 9-2320-285-10 for operation of fifth wheel.

b. If above conditions are met, go to step 2 below.

Step 2.

Check if bleed valve is fully closed (valve handle in vertical position).

a. If bleed valve is open, close it fully.

b. If bleed valve is fully closed, go to step 3 below.

WARNING

Do not remove filler cap when hydraulic oil is hot. Hot oil can cause

severe injury.

Step 3.

Remove hydraulic reservoir filler cap and check oil level.

a. If oil level is below bottom of filter screen, fill with hydraulic oil (para 2-78c) until level is at bottom

of filter screen.

b. If oil level is at bottom of filter screen, go to step 4 below.

WARNING

Do not remove filler cap when hydraulic oil is hot. Hot oil can cause

severe injury.

Step 4.

Remove hydraulic reservoir filler cap and check for contaminated oil.

a. If hydraulic oil is contaminated (oil feels gritty, has milky color, is dark and thick, or smells

scorched), drain and flush hydraulic system and replace oil filters (para 2-78c and 2-78b(1)).

b. If hydraulic oil is not contaminated, go to step 5 below.

2-862