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DEC 09, 2025

Inside the Power Unit: Electrical and Hydraulic Components on the Anthony MTU-GLR Tuckunder Liftgate

The Anthony MTU-GLR and Anthony MTU-GLR-WR tuck under liftgate families use a centralized hydraulic and electrical system designed to provide reliable performance, controlled lifting behavior, and safe power management for commercial fleets.

Anthony notes that MTU-GLR tuck under liftgates are factory assembled, energized, and tested, and ship completely assembled for fast, clean, and easy installation. This factory setup includes the integrated power unit and wiring that are the focus of this article.

• Documentation Resources from Palfinger
• Power Unit Components
• Hydraulic System Behavior
• Electrical System Overview
• Optional Control & Power Management Devices
• Component Protection & Best Practices
• Conclusion

Documentation Resources from Palfinger

Information in this article is sourced from Anthony MTU-GLR manuals and brochures, as well as the LiftGateMe team expertise. Always refer to your specific liftgate’s manuals for complete procedures and serial number, model, and year-specific details.

Reference PDFs used:

• Anthony MTU-GLR Installation Manual
• Anthony MTU-GLR Operation Manual
• Anthony MTU-GLR Brochure (2014)
• Anthony AST Installation Manual

Power Unit Components

The MTU-GLR power unit is part of Anthony’s CHS – Centralized Hydraulic System, which houses all sensitive hydraulic and electrical components within a stainless steel pump box. This centralized layout supports durability and service access for tuck under liftgate fleets.

Electric Motor

The electric motor is identified in the Power Unit Nomenclature diagram. It provides the mechanical drive for the hydraulic pump whenever the motor start solenoid is energized.

• Shown as “Electric Motor” in the pump box assembly.

Motor Start Solenoid

The motor start solenoid is wired to the control switch (white wire) and is responsible for energizing the motor when the UP function is activated.

• The troubleshooting chart in the Operation Manual calls out a bad motor start solenoid as a possible cause if the motor does not run.

Power-Up and Power-Down Solenoids

Two solenoid/valve assemblies control hydraulic flow:

• Power UP solenoid/valve (green control wire)
• Power DOWN solenoid/valve (red control wire)

Both are shown in the power unit diagram with their respective high-pressure hoses. These valves route pressurized oil to raise or lower the liftgate in a controlled manner.

Adjustable Relief Valves

The adjustable relief valves are mounted on the pump/manifold block and provide overpressure protection within the hydraulic circuit. They are explicitly labeled in the Power Unit Nomenclature drawing.

Pressure-Compensated Flow Valve

Anthony highlights a Pressure Compensated Flow Valve as a standard feature:

• Provides constant, controlled speeds at all times
• Helps prevent “free-fall” under certain hydraulic failures

In the hydraulic layout, a flow control valve is shown in the circuit feeding the cylinder.

Hydraulic Pump

The pump is driven directly by the electric motor and is identified in the same power unit diagram. It supplies the flow required for both power-up and power-down operation.

Reservoir, Fill Port, and Breather

The reservoir, with its fill port and breather cap, is illustrated as part of the pump box assembly. It provides fluid storage and venting for the hydraulic system.

High-Pressure Hoses

The system has two separate high-pressure hoses:

• Power Up High-Pressure Hose
• Power Down High-Pressure Hose

These hoses connect the pump unit to the cylinders and must be routed to avoid interference and abrasion during operation.

The MTU-GLR’s power unit consolidates motor, pump, valves, reservoir, and fusing inside a protected stainless steel enclosure. This centralized approach is a key reliability feature for tuckunder liftgate fleets, especially where exposure to weather and road debris is a concern.

Hydraulic System Behavior

Anthony’s Gentle Level Ride (GLR) design describes how the platform stays level, contacts the ground, and then tilts before re-leveling at the start of the lifting cycle. In this section, we focus on the hydraulic behavior that supports that motion.

Hydraulic Up/Down Cycle

The Operation Manual explains how the platform is raised and lowered:

• Pressing DOWN lowers the folded platform to the ground, then the platform unfolds before the UP/DOWN cycle is used for loading.
• During normal operation, pressing UP causes the platform to tilt up and then begin raising; pressing DOWN causes it to lower until it contacts the ground and then tilt toward the ground.

The power unit diagram shows that this behavior is supported by the motor, pump, and the power-up and power-down hoses/valves.

Both the 2014 MTU-GLR and 2016 MTU-GLR-WR brochures list “Power Down – Reliable cycle time in all weather conditions” as a key feature.

Power-Down Function

The brochures highlight Power Down as a major advantage of both Anthony MTU-GLR and MTU-GLR-WR models.

The hydraulic schematic confirms a dedicated power-down solenoid and hose, which indicates an actively controlled lowering circuit rather than relying solely on gravity.

Hydraulic Fluid Type

Anthony specifies the hydraulic fluid in two ways:

• A decal on the reservoir states: “This hydraulic reservoir is filled with Kendall Glacial Blu hydraulic fluid. Use ONLY the same or equivalent fluid.”
• The Operation Manual states to use the recommended Hyken Glacial Blu anti-wear, low-viscosity hydraulic fluid in the power unit reservoir.

In practice, these refer to the same product line, and the manuals consistently require the use of this fluid or an equivalent.

Fluid Level and Capacity Guidelines

For power-down models, the Operation Manual states:

• With the platform fully raised, the oil level should be within ½ inch of the top of the reservoir.

The Installation Manual’s final checklist instructs installers to verify that the reservoir is filled with Hyken Glacial Blu to approximately 2 inches from the top of the reservoir with the platform fully raised.

Contamination and Change Intervals

The Operation Manual instructs:

• Change the fluid if contaminated or dirty
• Change the fluid every 12 to 24 months, depending on use

It also warns not to mix hydraulic oil with automatic transmission fluid and not to use brake fluid.

The MTU-GLR hydraulic system combines controlled power-up, active power-down, and a pressure-compensated flow valve to maintain predictable movement and prevent free-fall under certain failure conditions. For fleets running tuck-away liftgate or tuckaway liftgate configurations in varying climates, the specified Glacial Blu fluid and documented fill procedures are critical to maintaining performance.

Electrical System Overview

The electrical system connects the truck battery to the pump and control circuits through fused power cables and a curbside-mounted control switch.

Power Cable Routing

The Installation Manual states:

• Never secure the power cable where it can contact sharp edges, fuel lines, brake lines, air lines, exhaust systems, or other objects that can cause damage.
• A cut battery cable can cause sparks, component damage, and potential loss of vehicle control.

Grounding Requirements

Grounding guidelines include:

• Install a ground strap of the same gauge or larger than the liftgate power cable between the pump box and truck frame.
• Improper grounding can cause electrical current to travel through brake lines or steel braided hoses, causing failure and loss of vehicle control.

Control Switch and Wire Colors

The control switch is mounted on the truck’s rear curbside post, so the operator can stand at the curbside while using the liftgate.

The Power Unit Nomenclature describes the control wiring colors:

• White wire – to motor start solenoid
• Green control switch wire – tied to yellow solenoid wire for power UP
• Red control switch wire – tied to yellow solenoid wire for power DOWN
• Black wire – 10 Amp in-line fuse connected to battery cable terminal

Circuit Protection (Fuses)

Anthony provides multiple layers of electrical protection:

• 200 Amp fuse – “Circuit Protection – 200 Amp fuse protects truck wiring from a ‘dead short’.”
• 175 Amp fuse – A separate power cable with 175 Amp fuse is shown in the Power Unit Nomenclature.
• 10 Amp in-line fuse – Protects the control circuit; the decal and text explain replacement of the 10A inline fuse in the pump box.

The Operation Manual provides detailed replacement procedures for the 200A and 175A fuses and notes that the power cable must be disconnected before fuse replacement to avoid electrical arc hazards.

The MTU-GLR electrical system combines large-capacity main fuses, a separate control-circuit fuse, and explicit routing and grounding requirements. For fleets searching for tuck under liftgate parts or OEM liftgate parts, following these documented guidelines helps preserve system safety and reliability.

Optional Control & Power Management Devices

Anthony recommends devices that disconnect power when the liftgate is not in use, to prevent accidental or unauthorized operation.

Cut-Off Solenoid

The Installation Manual recommends the A-133036 Cut-Off Solenoid Kit for all 12V electric liftgates and notes it is essential for tilt-cab applications.

• Installed between the vehicle battery and the fuse assembly
• Uses a lightweight control wire to the cab-mounted on/off switch rather than a large power cable
• A wiring diagram shows the solenoid placed between the battery and a long power cable to the power unit

Cab Cut-Off Switch

The manual separately describes a cab cut-off switch, which is also recommended:

• Mounted in the cab of the truck
• Disconnects power from the liftgate when switched off
• A wiring diagram shows the cab switch in series with the main power cable and fuse

Anthony explicitly states that installing a cut-off solenoid or cab cut-off switch helps prevent accidental or unauthorized use of the liftgate.

Optional cut-off devices don’t change hydraulic behavior, but they are strongly recommended for safe power management and to protect against unintended operation of the tuck under liftgate when the vehicle is unattended.

Component Protection & Best Practices

Anthony’s manuals include safety guidance specifically related to the electrical and hydraulic systems of the liftgate.

Battery & Fuel Tank Safety

The Installation Manual warns:

• Keep sparks, lighted matches, and open flames away from the top of the battery; battery gas can explode.
• Avoid sparks near the truck’s fuel tank, brake lines, or other flammable components.

Handling Electrical Components

Key recommendations include:

• Disconnect the power cable from the vehicle battery before disassembling the fuse holder to replace the fuse.
• Use corrosion-inhibiting lubricant on terminal ends, studs, and nuts in the liftgate electrical system (but do not apply petroleum-based lubricant to the motor start solenoid).

Hydraulic Fluid Compatibility

Anthony specifies:

• Use only Hyken Glacial Blu (labeled as Kendall Glacial Blu on the reservoir decal) or equivalent hydraulic fluid.
• Do not use brake fluid.
• Do not mix hydraulic oil and automatic transmission fluid due to compatibility concerns.

Hose and Component Protection

The Installation Manual’s final checklist instructs the installer to:

• Ensure hydraulic hoses are routed to prevent rubbing against any surface while the platform cycles.
• Confirm there are no hydraulic leaks and that all parts are in good working condition.

Battery safety, correct fuse procedures, proper grounding, and using only specified hydraulic fluids all contribute directly to system performance and operator safety. For operators and mechanics working with tuckunder liftgate systems, these best practices are as critical as any mechanical inspection.

Conclusion

The electrical and hydraulic systems of the Anthony MTU-GLR and Anthony MTU-GLR-WR are engineered as a centralized, protected subsystem that supports the Gentle Level Ride platform behavior. Key reliability features documented by Anthony include:

• A CHS centralized hydraulic system with stainless steel pump box
• A pressure-compensated flow valve to control speed and help prevent free-fall under certain hydraulic failures
• Specified Glacial Blu hydraulic fluid and clear fluid-change guidelines
• Multiple levels of circuit protection (200A or 175A main fuse plus 10A control fuse) and recommended cut-off devices

These subsystems are the backbone that powers the mechanical platform system you describe in your other post. For help selecting an appropriate tuck-under liftgate for sale or sourcing the correct tuck under liftgate parts and OEM liftgate parts for the MTU-GLR family, contact our team at LiftGateMe for assistance.