APRIL 10, 2025

Essential Maxon BMR-A Parts: Maintenance, Troubleshooting, and Replacement Guide

The BMR-A by Maxon Liftgate is built to handle heavy loads and withstand rigorous use. However, maintaining optimal performance requires proper care and timely replacement of key components. In this guide, we will cover the most critical BMR-A parts, including the control boxes, hydraulic cylinders, solenoids, toggle switches, and tandem assemblies.

We will explore maintenance practices, basic troubleshooting steps, and replacement procedures to keep your liftgate functioning efficiently.

These are the key Maxon Liftgate Parts that we’ll cover in this article:

• Control Box BMR-A Gravity Down (Part Number 280252)
• Control Box BMR-A Power Down (Part Number 280253)
• Main Toggle Switch Assembly (Part Number 268142-01)
• Solenoid Switch Assembly (Part Number 284080-01)
• Upper Tandem Assembly, RH Runner (Part Number 268866-03)
• Hydraulic Cylinder (1-3/4” Dia. x 53-1/8” Stroke) (Part Number 280663-01)
• Hydraulic Cylinder (2” Dia. x 53-1/8” Stroke) (Part Number 280663-02)
• Closing Cylinder (Part Number 264103)

Control Box Switches

(Note: All troubleshooting and replacement steps in this section are sourced from the maintenance manual Dec 2009, Rev. D)

Gravity Down vs. Power Down

Managing the lifting and lowering of the platform is crucial for efficient liftgate performance. Maxon BMR-A liftgates use control boxes to manage these movements, and there are two main configurations based on the liftgate model and application:

• 280252 (Gravity Down): Uses gravity to lower the platform, minimizing hydraulic usage and wear.
• 280253 (Power Down): Actively powers the lowering of the platform, useful in scenarios where controlled descent is required.

If your liftgate isn't working as expected, troubleshooting the control box is a good starting point. Here are some steps to help you diagnose and resolve issues:

Troubleshooting Steps:

• Inspect Wiring: Loose or corroded connections can cause the control box to fail.
• Test Switches: Verify continuity using a multimeter.
• Check Box Integrity: Physical damage can affect switch performance.

Replacement Procedure:

• Disconnect Power: Turn off power to the liftgate.
• Remove Existing Box: Unbolt the unit and disconnect the wiring.
• Install New Box: Follow the wiring diagram and ensure proper grounding.
• Test the Liftgate: Confirm that the new control box functions correctly.

Toggle Switch Assembly

The Maxon lift gate switch plays a vital role in your liftgate's operation, making it an essential component for reliable performance. Unlike the control box switches mentioned above, this section is in reference to the single toggle switch on your liftgate.

(Note: All troubleshooting and replacement steps in this section are sourced from the maintenance manual Dec 2009, Rev. D)

Function and Common Issues

The main toggle switch assembly (268142-01) is a crucial component for user control over liftgate operations.

Troubleshooting:

• Inoperative Switch: Check for broken or worn contacts.
• Erratic Function: Test the switch continuity with a multimeter.

Replacement Steps:

• Power Off: Disconnect the power to avoid electric shock.
• Remove Old Switch: Unscrew the mounting and disconnect wiring.
• Install New Switch: Follow the provided wiring diagram to ensure correct connections.
• Test the Liftgate: Make sure the new switch is operational.

Solenoid Switch Assembly

Like other Maxon liftgate solenoids, these are essential components that control hydraulic functions and are usually found on the power unit. Built for durability, they’re designed to withstand heavy use and environmental factors.

(Note: All troubleshooting and replacement steps in this section are sourced from the maintenance manual, Sept 2013, Rev. L)

Purpose and Maintenance

The solenoid switch assembly is essential for controlling hydraulic functions, particularly during all power operations.

Troubleshooting:

• Electrical Faults: Inspect wiring connections and check for signs of corrosion.
• Voltage Issues: Use a multimeter to ensure the solenoid is receiving adequate voltage.

Replacement Steps:

• Turn Off Power: Disconnect power to the liftgate.
• Remove Solenoid: Unbolt the assembly and disconnect the wires.
• Install Replacement: Follow the wiring diagram from the manual to ensure correct installation.
• Test Operation: Confirm that the new solenoid functions correctly.

Tandem Assembly

(Note: All troubleshooting and replacement steps in this section are sourced from the maintenance manual Sept 2013, Rev. L)

Importance and Maintenance

Troubleshooting:

• Structural Damage: Check for cracks or bending in the tandem arms.
• Friction Issues: Lubricate the moving parts to reduce wear.

Replacement Steps:

• Secure Platform: Make sure the platform is safely supported.
• Remove Damaged Assembly: Unbolt and detach the worn tandem assembly.
• Install New Tandem: Align and secure the new assembly according to the manual.
• Verify Stability: Check that the platform moves smoothly and securely.

Hydraulic Cylinder (1-3/4” Dia. x 53-1/8” Stroke) (Part Number 280663-01)

The hydraulic cylinder (280663-01) is designed to handle lifting operations in BMR-A models with capacities between 3500 and 4400 lbs. Proper maintenance and timely replacement help maintain optimal performance.

This information is sourced from Maxon liftgate source: m-07-16k-eo15604-bmrsd-parts.pdf, (2016, Rev. K)

Troubleshooting:

• Fluid Leak: Inspect the seals for visible signs of leakage and replace if damaged.
• Slow Movement: Check the hydraulic fluid level and ensure that air is not trapped in the system.
• Cylinder Noise: Look for internal damage or signs of hydraulic fluid contamination

Replacement Steps:

• Disconnect Power: Turn off the liftgate power to avoid accidents.
• Relieve Pressure: Disconnect hydraulic hoses from the cylinder, ensuring that pressure is fully released.
• Remove Cylinder: Unbolt and carefully extract the old cylinder from its mounting.
• Install New Cylinder: Secure the new cylinder in place, reattach hoses, and check for leaks.
• Test Operation: Ensure smooth and efficient movement after installation.

Hydraulic Cylinder (2” Dia. x 53-1/8” Stroke) (Part Number 280663-02)

This hydraulic cylinder (280663-02) is designed for BMR-A models with higher capacities ranging from 5500 to 6600 lbs. It is essential for lifting heavy loads efficiently.

This information is sourced from Maxon liftgate source: m-07-16k-eo15604-bmrsd-parts.pdf, (2016, Rev. K)

Troubleshooting:

• Fluid Leakage: Inspect for worn or damaged seals and replace as needed.
• Irregular Movement: Ensure fluid levels are adequate and bleed the system if air is detected.
• Unusual Noise: Examine the cylinder for internal damage or fluid contamination.

Replacement Steps:

• Secure Platform: Make sure the liftgate is in a lowered and safe position.
• Relieve Hydraulic Pressure: Disconnect the hydraulic lines cautiously to avoid fluid spills.
• Remove the Cylinder: Carefully unbolt and extract the defective cylinder.
• Install Replacement: Follow the manufacturer’s diagram for proper alignment and secure the new unit.
• Test and Inspect: Run the liftgate to check for proper movement and stability.

Closing Cylinder (Part Number 264103)

The closing cylinder is crucial for securing the platform in place when the liftgate is not in use. It ensures that the platform remains locked and stable during transit.

This information is sourced from Maxon liftgate source: m-02-23j-eo14832-bmra-cs-parts.pdf, (2016, Rev. J)

Troubleshooting:

• Platform Does Not Stay Closed: Check for hydraulic fluid leaks and inspect the cylinder for pressure loss.
• Unresponsive Locking Mechanism: Verify that the control box is working correctly and that the hydraulic fluid level is sufficient.

Replacement Steps:

• Lower Platform: Unfold the liftgate and lower the platform to a comfortable working height.
• Disconnect Hydraulic Lines: Remove the power open and power close hydraulic hoses carefully, plugging them to prevent spills.
• Remove Cylinder: Unbolt the lower and upper pins, then remove the cylinder from its mounting.
• Install New Cylinder: Place the new cylinder in position, secure the pins, and reconnect the hydraulic hoses.
• Test Locking Mechanism: Cycle the liftgate to ensure the platform locks properly.

Conclusion

Keeping your Maxon BMR-A liftgate in optimal condition is essential for minimizing downtime and ensuring reliable performance. Regular maintenance, prompt troubleshooting, and using high-quality OEM parts can make all the difference. However, if your liftgate still encounters issues despite your best efforts, it may be time to seek professional assistance. For more in-depth guidance and help finding a qualified service provider, check out our comprehensive liftgate repair guide.