How Do Forklift Hydraulics Work?
Forklifts are an essential tool in a warehouse environment. Brand-new forklifts can handle loads up to 5000 kg, which makes them an important asset for your workforce.
What are Hydraulic Forklifts Used For?
Forklifts powered by hydraulic systems are commonly used in warehouses, manufacturing facilities, construction sites, and other industrial settings to lift and transport heavy loads. The hydraulic power enables the forklift to lift loads weighing thousands of kilos up to significant heights safely and efficiently.
Key uses for hydraulic forklifts include pallet loading/unloading, stacking materials on shelves, transferring loads between locations, loading trucks, and more. Their versatility and ability to operate in tight spaces make hydraulic forklifts a vital asset in many operations.
A Brief Look at Hydraulics
The foundations of hydraulics date back to ancient civilisations like Egypt and China that used water to operate machinery. Early hydraulic applications included irrigation systems, water wheels, and primitive pumps.
In the 17th century, Blaise Pascal discovered the fundamental principles of hydraulic pressure transmission. Later, Joseph Bramah patented the hydraulic press in 1795, allowing much heavier weights to be lifted. In the late 19th century, hydraulics transitioned from water to oil-based fluids.
Modern hydraulic technologies emerged in the 20th century driven by the aviation and manufacturing industries. Applications grew to include construction equipment, machine tools, industrial processes, and more.
In today’s world, modern hydraulic systems allow heavy loads to be lifted with little effort from the operator by relying on the principles of hydraulic mechanical advantage. Warehouses and industrial environments would be far less productive and safe without hydraulic forklifts to do much of the heavy lifting.
How Does a Forklift Hydraulic System Work?
The hydraulic pump, powered by the forklift engine, draws hydraulic fluid from the tank and pressurises it up to several thousand psi. This pressurised fluid flows through valve blocks that regulate its distribution.
When the operator moves the control lever, valves open to send pressurised fluid into the lifting cylinder and raise the fork carriage. To lower the load, valves open that allow the fluid to return to the tank, causing the carriage to descend. Tilt cylinders mounted on the carriage use fluid pressure to angle the forks up or down. The valves ensure smooth and precise control of all hydraulic cylinder movements while the forklift is in operation.
Forklift Hydraulic Components
Key components of a forklift hydraulic system include:
- Tank: Also called a sump, the thank is where the reservoir of hydraulic fluid is stored and is usually found in the frame of the forklift.
- Pump: This pushes a constant stream of hydraulic fluid through to the control valve. Electric forklifts have two hydraulic pumps: the second is connected to the power steering.
- Control valve: This controls the amount of liquid and where it is directed.
- Relief valve: This is an important safety feature, as it prevents a system overload that would lead to ruptured pipes and leaks. As pressure rises, the valve opens and redirects liquid back to the sump.
- Return lines: These direct liquid back to the pump.
- Cylinders: These lift the fork carriage and tilt forks.
- Filters: Filters remove debris from hydraulic fluid.
Hydraulics used in forklifts are usually oil-based or water-based, but they may also use synthetic fluids.
Essential Forklift Hydraulic Maintenance Tips
An alarming one in five workplace fatalities in the UK are caused by a forklift truck or industrial vehicle, which means it is essential to adhere to health and safety guidance. Implementing a maintenance schedule for your forklift trucks is an important part of this.
To maximise uptime and safety, regular maintenance of the hydraulic systems on your forklifts is crucial, and forklift servicing is a service we offer our customers.
The key areas to maintain in a forklift hydraulic system are:
- Inspect hoses and cylinders for damage or leaks. Replace worn components.
- Check fluid levels often to maintain proper reservoir level. Top up when low.
- Change hydraulic fluid and filters per the manufacturer’s schedule.
- Inspect valves, pumps, and motors. Ensure tight fittings.
- Keep hydraulic components clean of dirt, grime, and grease.
- Monitor fluid temperature; excess heat can degrade fluid.
- Drain moisture from reservoirs to reduce corrosion.
Catching problems in a hydraulic system early prevents major repairs down the road. It can also help to prevent injuries and accidents.
Common Forklift Hydraulics Repair Issues
Some of the most common hydraulic repair areas that typically need attention are:
- Hose leaks or ruptures
- Seal/cylinder replacement
- Pump rebuild/replacement
- Valve malfunctions
- Contamination causing wear or clogs
- Overheating issues
- Loss of pressure
- Lift instability
Many issues arise from fluid contamination or component wear over time. Catching problems before failure occurs is optimal to avoid costly productivity delays.
How are Hydraulic Issues Diagnosed?
Technicians use various diagnostic methods when assessing problems with a forklift hydraulic system. These include:
- Visual inspection to identify leaks/damage
- Pressure testing to pinpoint leaks
- Flow testing to check pump output
- Checking fluid for proper levels/quality
- Using diagnostic software to assess errors
- Load testing to evaluate lift performance
Identifying the root cause of problems guides the proper repair approach.
Is it Time to Upgrade Your Hydraulic Forklift?
Upgrading to a new hydraulic forklift can optimise productivity and safety in the following scenarios:
- Maintenance costs are excessive
- Downtime is increasing
- Parts are difficult to source
- Capacity is no longer adequate
- Features lag current technology
Newer forklifts offer advantages like lower emissions, intuitive controls, and enhanced ergonomics.
Look at our range of new and used forklifts for sale and hire to see if we have the perfect forklift truck for your business. We stock forklifts from manufacturers like Nissan, Toyota, and Mitsubishi. All of our forklifts come with a full warranty and L.O.L.E.R. health and safety certificate.
Regular maintenance and inspection of the hydraulic system keeps forklifts running safely and efficiently. But over time, upgrading the equipment can provide additional benefits for your evolving operations.
Contact us today to discuss your needs.
