Why won't my forklift lift?

The most common causes are low hydraulic fluid, a clogged hydraulic filter, a worn hydraulic pump, or a relief valve set too low. A worn lift cylinder piston seal can also cause the mast to lift weakly and then drift down under load.

Can I check why my forklift isn't lifting myself?

An operator can safely check the hydraulic fluid level and inspect for obvious leaks. Beyond that, diagnosing pump output, relief valve settings and cylinder condition requires pressure testing equipment and should be done by a qualified technician.

How long does it take to repair a forklift that won't lift?

Simple causes like a low fluid level or clogged filter can be fixed in under an hour. A hydraulic pump replacement typically takes 2–4 hours. A lift cylinder reseal requires the cylinder to be removed and bench-resealed, which may take 1–2 working days.

24/7 Emergency Forklift Repair — Call 074 238 1260

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Common Problems

Forklift Not Lifting

When your forklift won't raise its forks — or lifts too slowly to work — the machine is down until the cause is found. Most lift failures trace to the hydraulic system and can be diagnosed and repaired same-day by an experienced technician.

Call Now: 074 238 1260

What Causes This?

Low hydraulic fluid level

The most common and easiest to fix. Low fluid starves the pump, causing cavitation and reduced output pressure. Check the reservoir first.

Clogged hydraulic filter

A blocked filter restricts flow to the pump. Common after long service intervals or in dusty environments. Replacement is inexpensive but critical.

Worn hydraulic pump

Gear or piston pump wear reduces output pressure and flow. The first sign is slow lift; the pump then begins to whine and eventually fails completely.

Relief valve stuck open or set too low

The relief valve limits maximum system pressure. If it sticks open or is set below the required lift pressure, the system vents before generating enough force to lift the load.

Lift cylinder internal bypass

Worn piston seals in the lift cylinder allow high-pressure fluid to bypass the piston. The cylinder extends weakly and the mast drifts down under load.

Mast chain binding or damaged

A kinked, corroded or stretched mast chain can bind in the mast channels, preventing normal mast travel even when the hydraulic system is generating adequate pressure.

What You'll Notice

Symptom	Most Likely Cause
Forks won't rise at all	No hydraulic pressure — pump failure or no fluid
Forks lift very slowly	Low fluid, clogged filter, worn pump or low relief valve setting
Forks lift but mast drifts down with load	Cylinder internal bypass or control valve leakage
Lift works empty but not under load	Worn pump insufficient for working pressure, or relief valve too low
Jerky or uneven mast movement	Air in hydraulic system (cavitation), contaminated fluid, or binding chain
Pump whines or makes unusual noise during lift	Cavitation from low fluid or clogged filter; immediate attention required

Can You Fix It Yourself?

Operator Can Check

✓Hydraulic fluid level — dipstick or sight glass on the reservoir
✓Visible hydraulic leaks under the machine or on cylinder rods
✓Whether the fault appears on empty lift or only under load
✓Whether all hydraulic functions are affected or only lift

Needs a Technician

✕Hydraulic pressure testing (requires calibrated gauge and test procedure)
✕Relief valve adjustment or replacement (incorrect setting destroys the pump)
✕Pump removal, inspection and replacement
✕Cylinder removal, bench resealing and reinstallation
✕Hydraulic system flush after contamination

How We Fix It

Hydraulic system pressure test

We connect a calibrated hydraulic pressure gauge to the system to measure actual working pressure versus the manufacturer's specification. This immediately identifies pump output failure versus relief valve issues.

Fluid condition and level assessment

Fluid is checked for level, colour, foam and contamination. A contaminated system is flushed before any new components are fitted.

Filter inspection and replacement

The hydraulic filter is removed and inspected. Metallic particles in the filter indicate internal wear and change the diagnostic path. The filter is replaced as a standard item.

Pump inspection or replacement

If pressure testing confirms pump failure, the pump is removed and inspected. We carry common replacement pumps in stock and can often complete same-day.

Relief valve check and adjustment

The relief valve setting is checked against specification. If stuck or out of spec, it is serviced or replaced and reset to the correct pressure.

Cylinder and mast inspection

If pressure tests are normal but lift remains faulty, the cylinder is bench-tested for internal bypass and the mast channels are inspected for binding, corrosion or chain damage.

Forklift Down? Call Now.

We cover the entire Vaal Triangle. Same-day diagnosis on most hydraulic lift faults.

074 238 1260