Troubleshooting

1. Check the reservoir oil level to see that it is sufficient.
2. Remove and inspect the inlet hose for blockage and replace as needed.
3. Clean or replace the reservoir breather cap.
4. Check to see if ball valves are open on hydraulic lines.

Replace pump as required. Check cleanliness of oil, replace if dirty.

Why does the cylinder seem to chatter or vibrate?

1. The first thing to check is the cylinder alignment. Excess friction due to misalignment can cause cylinder chatter. Check to see if the cylinder is mounted and aligned correctly. Correct any mounting or alignment problems.
2. Check for air in the hydraulic system. Most cylinders have an internal auto-bleed design. Follow the initial start-up procedure to bleed the cylinder of air. Look for any other places where air might be introduced into the system, such as the pump inlet line. Seal off any leaks in the system.
3. Check fluid level in the reservoir to make sure the system has enough fluid to extend the cylinder completely. Add fluid as needed.
4. Check that the reservoir air breather is not blocked. If the breather appears dirty, replace or clean the breather.
5. Check that the pump is functioning, moving oil, and not worn. The gears inside a pump can wear over time. When the gears wear there is more room around the gear allowing oil to just move around inside the pump meaning that there is less oil being forced out of the pump. To check the amount of oil flow a flow meter can be installed in the line.
6. Check that unloading or relief valves are not misadjusted. These valves may be set too low and bypassing some of the pump flow. Check the Owners Manual, for proper relief valve setting.
7. Check for excessive back-pressure on external drain valves. Should the pressure be too high look at plumbing the lines directly back to tank.
8. Check for any check valves in the system and confirm that they are working properly.
9. The cylinder may have internal damage. A determination must be made as to how to have the cylinder repaired or replaced.

1. Following are some possibilities that could account for a cylinder mis-staging. First check that all of the air has been removed from the cylinder. Cylinders with the internal auto-bleed design should bleed the air out automatically by cycling the cylinder several times. If equipped with a manual air bleed valve, follow the air bleed procedure to remove entrapped air. The procedure for manually bleeding a telescopic cylinder is in the Owners Manual.
2. Mechanical frictional force is another cause of cylinder mis-staging. Because of the seal design used, there is no adjustment required to the seal. Therefore, should mis-staging occur adjusting the retaining glands would not have any affect. Inspect the cylinder stage sleeve for straightness. A bent tube will cause added friction between moving parts. If any parts are bent, replace the cylinder.
3. Check to see what pressure rating the system is running at. The system pressure may be or was too high and caused the cylinder to swell in the seal area. Upon retracting the cylinder, the swelled area will be forced into the next larger stage. These two stages may, then, be stuck together and not be able to extend. Inspect the sleeves for swelled areas and, if found, replace the cylinder.
4. Operating over the recommended engine rpm’s will cause the cylinder to mis-stage. This could cause damage to cylinder, pto and pump.

1. The first thing to check is that there is nothing mechanically holding the dump body up.Following the safety guidelines remove any obstructions under the body. Remove any obstructions that keep the body from coming down.
2. Mechanical frictional force is something that could hinder a cylinder from coming down completely. Because of the seal design used, there is no adjustment required to the seal. Therefore, should sticking occur, adjusting the retaining glands would not have any effect. Inspect the cylinder stage sleeve for straightness. A bent tube will cause added friction between moving parts. If any parts are bent, replace the cylinder.
3. Check to see what pressure rating the system is running at. The system pressure may be or was too high and caused the cylinder to swell in the seal area. Upon retracting the cylinder, the swelled area will be forced into the next larger stage and not allowed to fully retract. These two stages may, then, be stuck together and not be able to extend. Inspect the sleeves for swelled areas and if found, replace the cylinder.
4. Check that the reservoir air breather is not blocked. If the breather appears dirty, replace or clean the breather.
5. Check that the hydraulic components are working properly and not hydraulically locking the cylinder up.
6. Cylinders with internal auto-bleed design may have internal damage. Determine this cause by eliminating all the other possibilities.

1. First, check to see that there is 12VDC present at the switch. If there is no voltage, check the voltage at the source for the switch and termination points.
2. Assuming there is 12VDC at the switch, check for 12VDC at the valve. If there is not voltage at the valve, check the wiring from the switch to the valve.
3. Assuming there is 12VDC at the valve, check the air pressure. If there is no air pressure check the main air supply.
4. If the valve is working, check the cylinder. What is the condition of the rod? There can be a few things that can affect the rod. Make sure that the rod has not been painted. Also, check to see if the rod has been bent. Another check is to make sure the clevis pins are still in place.

1. More often than not, the valve will be working correctly. There may be cases where the solenoid went bad or there is contamination inside the valve causing it to stick. It is more likely that there is a bad connection to the solenoid.

1. All air valves will have a small amount of leakage. This should not result in any performance loss of the cylinders.
2. The first thing to do is to check that all air lines and fittings are intact.
3. Make sure the truck air pressure is less than 120 PSI, as this could account for some leakage.
4. Spray the valve at the mufflers with soapy water. If there are air bubbles present, there could be a leak in the cylinder or valve.
5. Make sure that the shop air pressure is less than 120 PSI. On a bench, take the valve off the cylinder and run the shop air pressure into the cap end of the cylinder. The cylinder will extend. Listen for leaks. If you can’t hear anything, the cylinder is good.
6. Send the valve back for evaluation.

1. Confirm that the power source is connected to the vibrator.
2. Confirm that all connections are intact and secure.
3. Check to see if there is current at the switch and at the vibrator.
4. Check to see that the unit is grounded properly.

1. Check to see that all mounting bolts are installed and tight.
2. Check to see that all welds are intact on the mounting assembly.
3. Check if the abnormal noise is coming from the inside of the vibrator.

1. Inspect connections and check for voltage at the solenoid. If no voltage check pto switch
2. If pto switch is a truck manufacture option and located in the dash take to an authorized truck dealer for troubleshooting.
3. If voltage is present at the solenoid and pto does not engage, replace solenoid. If pto still does not work contact Technical service at Ox Bodies.

1. Check to see if truck has 90psi air pressure
2. Check to make sure the pto has air supplied when switch is engaged. If no air supply check air lines for damage or kinks.
3. Check pto switch in cab

1. Check to see if truck has 90psi air pressure
2. Unplug the solenoid located at the rear of the truck. Check for voltage at hi-lift solenoid with hi-lift switch on.
3. If no voltage is present check the switch in the cab for voltage
4. If the switch doesn’t have voltage check the fuse panel located in the control box in the cab. If the fuse is good and the switch is supplied with power then the switch is probably faulty.
5. If high lift solenoid has power and still does not work check for air supply to high lift valve. Make sure you have an air supply of 90 psi at the valve.
6. If the valve has air supply and voltage, check to see if the air supply is going to air cylinders
7. If air is not being supplied when the solenoid is engaged the high lift valve is faulty.
8. If checks show good and still does not work the cylinders may be damaged.

1. Check tarp wire connections at battery terminals
2. Locate and check the auto reset breaker located in the battery box on the positive wire.
3. Check to see if a 12-volt signal is at the tarp relay. The tarp relay can be found by following the positive tarp wire from the battery.
4. Check for voltage at the tarp switch in the console and the fuse panel inside the console. Check to see if the voltage is coming from the switch to the tarp relay.
5. If all connections and voltage are good at the tarp relay then check for 12 volts at the tarp motor. Check wiring from relay to tarp motor. If this does not have a 12-volt signal then the relay will be faulty.
6. If voltage is supplied to the motor and the motor does not operate then you will need to replace the motor.