For decades, the unmistakable hum and physical resistance of hydraulic oil circulation directly beneath an excavator operator’s hands was the defining hallmark of machine performance. Today, that physical connection is rapidly fading.
The heavy construction equipment industry is undergoing a quiet but profound transformation. OEMs are replacing traditional mechanical pilot control systems in excavators in favour of full electric-over-hydraulic, or electro-hydraulic (EH), controls for enhanced performance and versatility.
There’s more to the transition than operator preferences or engineering simplification. It represents an entirely new way of managing machine dynamics, protecting thin profit margins and mitigating labour shortages on today’s construction job sites. The latest generations of crawler excavators entering the market are launching with EH controls as the standard set-up.
“At the end of the day, both pilot controls and EH controls direct the excavator’s hydraulics,” says Brian Kim, excavator product manager at DEVELON. “But with an EH system, you trade old-school mechanical simplicity for an entirely new realm of customizability, precision, and seamless technology integration.”
Pilot vs. EH controls
To better understand the scale of this industry trend, it helps to break down how these two excavator control designs handle everyday tasks like trenching and lifting material.
Kim explains that traditional pilot controls rely entirely on physical fluid dynamics to execute an operator’s commands. Inside a standard pilot-controlled excavator control, a dedicated, low-pressure pilot pump continuously forces hydraulic oil up into the cab and directly through the joystick housings.
“When an excavator operator moves a lever to swing the machine’s house or lift the boom, they are physically shifting a mechanical spool to route that low-pressure oil back down to the main control valve,” he says.
While mechanical pilot controls have traditionally been highly dependable, the configuration requires a complex web of hydraulic hoses routed directly inside the operator’s cabin, adding physical complexity and potential leak points to the machine’s layout.
The modern EH controls in many new excavators entirely eliminate the low-pressure pilot pump and the network of oil lines running into the operator’s cabin. Kim explains that mechanical joysticks are replaced with digital transducers that turn physical motion into data.
Key differences between mechanical pilot controls and EH controls
- Pilot systems use low-pressure hydraulic oil as their primary signal medium. EH platforms rely entirely on digital electrical currents.
- Mechanical set-ups require physical oil lines routed directly under the joysticks, whereas EH controls utilize a clean electronic wiring harness.
- A centralized controller sends precise electrical current to electro-hydraulic valves instead of fluid pressure that must physically shift valve spools to a digital framework.
“EH controls replace those hydraulic pilot signals with electronic inputs,” says Kim. “Instead of using oil to physically actuate the main control valve, the joystick sends an instantaneous electrical signal to a centralized controller. That controller then commands the electro-hydraulic valves to perform the desired function.”
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