How to Properly Bleed Air from a Dump Truck Cylinder

Bleeding air from your system is critical to maintaining or installing dump truck cylinders. Trapped air can contaminate your system’s hydraulic fluid, leading to degraded performances, damaged component parts, cavitation, and, in extreme cases, complete hydraulic cylinder failure.

Luckily, bleeding air from a dump truck cylinder is a straightforward process that can be incorporated into regularly scheduled maintenance routines. By releasing the pressure from an air bleeder valve, you can extend the lifespan of your dump truck cylinders, keep hydraulic cylinder fluid cleaner for longer, and demolish downtime for your dump truck.

Air Bleeder Valve Instructions for Different Types of Dump Truck Cylinders

Bleeding dump truck hydraulic cylinders involves bringing air to the top of the cylinder and releasing it. The process varies slightly depending on your machinery. Before conducting any maintenance, consult your manual for instructions specific to your dump truck hydraulic cylinder.

Single-Acting Telescopic Dump Truck Cylinders

Single-acting telescopic cylinders are often used in dump trucks due to their low-maintenance and cost-effective performances, and bleeding air from your system can be completed in a few steps:

1. Raise the dump body and cylinder to full extension. Leave the dump body in this position for several minutes to allow air to rise to the top of the cylinder.
2. Lower the dump truck cylinder until the front of the dump body is approximately 2 feet off the chassis frame.
3. Put the body up lever in the center/hold position
4. Open your air bleeder valve, following manufacturer instructions for your cylinder.
5. Wait until all trapped air has escaped from the air bleeder
6. When a full stream of hydraulic fluid escapes the air bleeder valve, the air bleeder valve can be closed.

Rod Type Dump Truck Hydraulic Cylinders

Before releasing air from the dump truck hydraulic cylinder, make sure the welded rod hydraulic cylinder is completely unpressurized with the air bleed valve pointing upwards and the piston rod retracted.

1. Open the air bleeder valve at the upper side of the dump truck hydraulic cylinder.
2. Set up the hydraulic system and start it.
3. Extend the piston rod slowly until hydraulic fluid comes out of the air bleeder valve.
4. Shut down the system, close the air bleeder valve, and depressurize the system.
5. Open the air bleeder valve at the lower side of the hydraulic cylinder.
6. Repeat the same process for bleeding air as the upper valve, retracting the cylinder instead of extending it.
7. Retest the hydraulic cylinder by extending and retracting the piston rod until it runs

Refilling Your System with New Hydraulic Fluid

No matter the type of cylinder that powers your equipment, refilling your dump truck hydraulic cylinder with new fluid after bleeding air will further improve performance. Always use clean, high-quality fluid with the right viscosity to ensure your dump truck cylinders operate smoothly and efficiently. Other methods of avoiding hydraulic system contamination include:

• Only using fluid that has been stored correctly
• Installing fluid bypass filters
• Replacing worn valves and components

Contact HCI for Built-to-Last Dump Truck Hydraulic Cylinder Replacements

While bleeding air from your dump truck cylinder will extend the lifespan of your equipment, you may eventually need to purchase a replacement. Hydraulic Cylinders, Inc. is here to help. We’ll get you back to work as soon as possible through same-day shipping on all in-stock cylinders and cylinder component parts, expert how-to guides, and custom hydraulic cylinder options. Contact us to learn more.