Fontaine and Holland Fifth Wheels Coupling
- Chock the front and rear trailer tires.
- Ensure the fifth wheel jaw is fully open and the operating
rod is in the unlocked position. See Fig. or
Fig..
Note: Make sure the safety latch is down when the control handle is locked.
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Unlocked
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Locked
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Safety Latch
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Lock Control Handle
Fig. 1, Fontaine Locking Mechanism
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Safety Latch
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Operating Rod (locked)
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Operating Rod (unlocked)
Fig. 2, Holland Simplex SE Locking Mechanism
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- Make sure the fifth wheel top plate is tilted so the ramps are as low as possible.
- Position the vehicle so that the center of the fifth wheel is in line with the trailer kingpin. The kingpin should be in a position to enter the throat of the locking mechanism.
- Adjust the trailer height if required.
For a standard fifth wheel plate , the trailer should contact the fifth wheel approximately 4 to 8 inches (10 to 20 cm) behind the fifth wheel pivot. See Fig..For a low-lube fifth wheel plate , the fifth wheel must slide freely under the trailer, and the trailer should contact the fifth wheel at the pivot. See Fig..
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Fifth wheel must lift trailer
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Adjust trailer height
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Ramps tilted down
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4 to 8 inches
Fig. 3, Trailer Connection Point, Standard Fifth Wheel Plate
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Adjust trailer height
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Ramps tilted down
Fig. 4, Trailer Connection Point, Low-Lube Fifth Wheel Plate
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- With the fifth wheel lock opening aligned with the trailer
kingpin, back the vehicle slowly toward the trailer. After sliding
under the trailer, STOP to prevent from hitting the kingpin too hard,
then resume backing slowly until the fifth wheel locks.On a standard fifth wheel, the fifth wheel must lift the trailer.On a low-lube fifth wheel, do not lift the trailer as this may damage the fifth wheel plate.
- Apply the vehicle parking brake.
- Perform a coupling inspection, checking that there is no
gap between the bottom of the trailer and the fifth wheel, and that
the kingpin is securely locked. See .
When lockup has occurred, the fifth wheel control handle moves to the locked position. Make sure that the safety latch is down over the lock control handle to hold the control handle in the locked position (the safety latch will only rotate down if the operating rod is fully retracted in the locked position). See Fig. for Fontaine fifth wheels. See Fig. for Holland fifth wheels.
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No gap between trailer and fifth wheel
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Kingpin inside lock
Fig. 5, Coupling Inspection
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- Release the vehicle parking brake. Test for kingpin lockup by slowly inching the vehicle forward, pulling on the trailer against the chocks.
- After lockup is completed, connect the tractor-to-trailer air system lines and the electrical cable to the trailer. Take care to prevent dirt or foreign material from entering the air system lines.
- Charge the air brake system with air, checking that the air connections do not leak.
- With the trailer tires chocked and the brakes set, check for clearance between the kingpin and the fifth wheel jaws by moving the vehicle forward and backward against the locked kingpin. If slack is present, uncouple the trailer and have the fifth wheel inspected and adjusted by a certified technician.
Notice: Attempting to couple at the wrong height may cause improper coupling, which could result in damage to the fifth wheel or kingpin.
Warning: A visual inspection is required by law. Some improper couplings can pass a pull test. Sound is not reliable. Get out of the cab and look. Incorrect coupling could cause the trailer to disconnect, possibly resulting in serious personal injury or death.
Notice: Always make sure the connection hanger keeps the trailer air hoses and electrical cables positioned so that they do not rub on anything. Rubbing may wear through hoses or cables, resulting in air leaks, or exposed or broken wires, potentially affecting trailer brake or electrical systems.
Warning: Incorrect fifth wheel lock adjustment could cause the trailer to disconnect, possibly resulting in serious personal injury or death.