“It powers up but won’t go” sounds like an electrical problem. The display is on, there are no obvious warnings, and the natural next step is to suspect the traction controller, the travel switch or the drive motor.
On this Hyster order picker, none of those were the problem. The machine could not travel because its drive brake never released.
Power is not the same as permission to move
An electric order picker needs several things to happen before it moves: the operator presence and enable circuits have to be satisfied, the controller has to command the motor, and the parking brake on the drive motor has to release. If any link in that chain is broken, the result from the platform looks identical: lights on, no travel.
That’s why a no-travel complaint has to be traced through the whole chain rather than started at the most expensive part.
What was found at the drive motor
Opening the drive-motor compartment showed several related failures in the brake-release assembly:
- The pin that secured the motor-brake lever had sheared.
- The threaded hole that pin screwed into was damaged.
- The push rod between the slave cylinder and the lever was missing.
- The brake fluid reservoir was empty.
With the lever disconnected and no push rod, nothing was left to move the brake off. The brake stayed applied, and the truck stayed put.
Repairing it instead of replacing around it
The threads
Putting a new pin into damaged threads would have left the linkage loose, and a pin that backs out puts the truck right back where it started, or worse. A thread insert restored the mounting point so the new pin could be secured properly without replacing a larger assembly that hadn’t actually failed.
The push rod
The correct push rod wasn’t available immediately. Rather than improvise a rod, the truck waited for the right part. Brake linkages depend on specific length and geometry; a homemade rod can change lever travel and leave the brake partly dragging or unable to hold.
The fluid
An empty reservoir means air in the circuit. Air compresses, so cylinder movement becomes weak or disappears. Topping off isn’t enough. The system was filled, the brake cylinder pressure was bled, and the master cylinder was bled to remove air before adjustment.
The service record didn’t show why the reservoir had gone empty, so no leak was blamed without evidence. What mattered was restoring the fluid correctly and making sure the level is watched from here on.
Proving it before release
With the spring rod, lever, new pin and push rod installed and the system bled, the brake was adjusted and tested. Travel was checked in both directions and brake application was confirmed before spilled fluid was cleaned up and the compartment closed.
What this job teaches
A machine with power is not a machine with every system working. When an electric truck won’t travel, check whether the brake is actually releasing before replacing controllers, switches or motors.
Details operators should report
- Powers on but won’t move in either direction
- Feels like it is pulling against the brake
- Travel that changes after the truck sits
- A change in brake feel
- Fluid under the drive-motor area
Those observations point a technician at the right system on the first visit.