how-to-inspect-forklift-hydraulic-hoses.html

Hydraulic hoses are easy to overlook until a leak appears.

On a forklift, they carry pressurized hydraulic oil between pumps, valves, cylinders and attachments. Some hoses also move repeatedly as the mast raises and lowers.

For this reason, hose condition should be checked before visible failure occurs.

OSHA includes hydraulic hoses, leaks and other visible defects in the forklift pre-operation inspection.

An operator does not need to dismantle the hydraulic system during a daily check.

The first step is simply looking for anything abnormal.

Warning signs include:

• Oil leakage
• Cracks or cuts
• Abrasion
• Exposed reinforcement
• Kinks
• Flattened or crushed areas
• Blisters or soft spots
• Damaged fittings
• Loose hose routing

Parker's hydraulic hose safety guidance identifies many of these conditions as reasons to shut down the system and replace the affected hose assembly.

A hydraulic hose may still hold pressure even after the outside cover has been badly worn.

But the outer cover protects the reinforcement underneath.

Repeated rubbing against:

• Mast channels
• Metal brackets
• Other hoses
• Attachment structures

can gradually wear through that protective layer.

If reinforcement becomes exposed, the damage should not simply be covered with tape and ignored.

Hose routing and clamps should also be checked so the replacement hose does not develop the same problem again.

Hydraulic hoses are designed to bend, but only within an appropriate bend radius.

A hose that is sharply kinked or repeatedly bent too tightly can experience internal damage even if the outside initially looks acceptable.

Parker specifically warns that installation below the specified minimum bend radius can significantly shorten hose life.

This becomes particularly relevant around forklift masts, where hoses may move during lifting and lowering.

A small hydraulic leak can be more dangerous than it looks.

High-pressure oil escaping through a tiny pinhole may form a very narrow jet that is difficult to see.

Do not run your hand along a hose to find the leak.

Parker warns that high-pressure hydraulic fluid can penetrate skin and cause serious injury.

If a leak is suspected, the truck should be stopped and inspected using the correct maintenance procedure after hydraulic pressure has been safely released.

There is no single operating-hour figure at which every forklift hydraulic hose must be replaced.

Service life depends on conditions such as:

• Operating pressure
• Oil temperature
• Hose movement
• Abrasion
• Routing
• Environment
• Duty cycle

Gates notes that hydraulic hose life depends on the actual application and recommends regular inspection for leaks, kinks, abrasion, blisters and other damage.

This means a hose on a lightly used indoor forklift may experience a very different service life from one working long shifts in a steel plant or outdoor yard.

A hose must be suitable for the hydraulic system in which it is installed.

This is why replacement should not be based only on:

"The diameter looks the same."

The hose and fittings must also suit the required pressure and hydraulic application.

We explain the relationship between pressure, flow and hydraulic force separately in what hydraulic system pressure means on a heavy duty forklift.

Using an unsuitable hose assembly can create a problem even if it physically fits the machine.

A standard forklift mainly requires hydraulic circuits for lifting and mast tilt.

Additional equipment may introduce more hoses and moving connections.

Examples include:

• Fork positioning
• Side shift
• Clamps
• Rotators
• Coil rams
• Other hydraulic attachments

For specialized forklifts with hydraulic attachments, hose routing should therefore be considered as part of the attachment installation rather than added casually after delivery.

The hose needs enough freedom to move without being stretched, pinched or repeatedly rubbing against another component.

Replacing the damaged hose is only part of the job.

The technician should also check why the original hose failed.

For example:

Abrasion may indicate poor routing.

A kink may indicate insufficient hose length or incorrect installation.

A leak at the fitting may involve the connection or sealing surface.

Repeated hose failure may justify checking the actual hydraulic operating condition.

This helps prevent the new hose from developing the same problem.

Before shipment, the complete hydraulic system should operate normally under the confirmed configuration.

Propolift's factory testing includes lifting, lowering, mast tilt and installed hydraulic attachment functions, together with checks for hydraulic response.
How Propolift Tests Heavy Duty Forklifts Before Delivery 

Once the forklift enters service, however, hose inspection becomes part of ongoing maintenance at the customer's site.

The operating environment and working hours will gradually affect hose condition.

A forklift should not continue normal operation when a hydraulic hose has a serious visible defect or leak that could make the truck unsafe.

OSHA states that a powered industrial truck that is defective or not in safe operating condition should be removed from service until the problem is corrected.

For heavy-duty machines, this matters because the hydraulic system may be supporting very large loads.

Buyers comparing different capacities can review the current Propolift heavy duty forklift range here.

Hydraulic hoses should not be judged only by whether they are leaking badly.

Important warning signs include:

abrasion, cracks, exposed reinforcement, kinks, damaged fittings, blisters and oil leakage.

Daily visual inspection can catch many of these problems early.

And if a leak is suspected, never try to locate a high-pressure leak with your hand.

The better approach is simple:

stop the machine, release the hydraulic pressure correctly and let qualified personnel inspect the hose assembly.

References

1. OSHA - Powered Industrial Trucks: Pre-Operation Inspection.
2. Parker Hannifin - Industrial Hose Safety Guide.
3. Parker Hannifin - Parker Safety Guide for Hydraulic Hose and Fittings.
4. Gates - Safe Hydraulics Pocket Guide.
5. Gates - Hydraulic Hose and Assemblies Service Life Guidance.
6. Propolift - How Propolift Tests Heavy Duty Forklifts Before Delivery.