Forklift Truck Lift Oil Cylinder — Single-Acting Hydraulic Lift Cylinder

Main Lift Cylinder

The primary lift actuator that extends the mast rails. One or two per mast channel, running the full height of the outer rail. These cylinders have the longest stroke in the forklift system — typically 1,500 mm — and are single-acting (gravity return). When the mast reaches maximum height, these cylinders are at full extension, carrying the entire load plus the mast weight as a structural column.

Short Lift / Free-Lift Cylinder

The inner cylinder that provides free-lift travel — raising the forks inside the collapsed mast before the mast itself begins to extend. It has a shorter stroke (500–900 mm) because it must fit within the collapsed inner rail. Includes an integrated chain sprocket for 2:1 stroke multiplication and a check valve for load holding. This is the 27-component architecture.

Bare-Actuator Lift Cylinder

The minimalist 8-component design — housing, rod, seals, steel ball check valve, and nothing else. No sprocket, no oil pipe. Used as an aftermarket replacement where the mast already has external sheaves and plumbing, or for non-forklift lift applications (tables, platforms, farm equipment) where the chain drive is handled externally.

Question 1: Does your mast have a free-lift function?

If the forks can rise without the mast rails extending, your mast has a free-lift function, and you need a short lift cylinder (Type B) for the free-lift stage in addition to the main lift cylinders (Type A) for the mast extension stage. If the mast rails begin extending immediately when the forks rise, you have a simplex or basic duplex mast and only need main lift cylinders (Type A).

Question 2: Does the existing cylinder have a chain sprocket on top?

If yes, you need the 27-component architecture with integrated sprocket (Type B). If no, you need either a main lift cylinder (Type A — no sprocket, long stroke) or a bare actuator (Type C — no sprocket, shorter stroke, external sheave).

Question 3: Is the stroke greater or less than 1,000 mm?

Greater than 1,000 mm → most likely a main lift cylinder (Type A). Less than 1,000 mm → most likely a short lift or bare actuator (Type B or C). Measure the stroke by fully extending the rod and measuring from the gland face to the rod end.

Question 4: Do the bore and stroke match a standard model?

If your measurements match one of the 10 standard models (5 main lift + 5 short lift), order the catalogue product for the fastest delivery and lowest cost. If any dimension deviates, order through the OEM custom service — Korea Ever-Power will manufacture to your exact specification.

The forks drift down slowly when holding a load — is this the lift oil cylinder?

Probably, but check two things first. First, verify the directional control valve is in exact neutral — even a slight offset allows oil to leak from the cylinder bore back to the tank, causing drift that looks like a cylinder problem but is actually a valve problem. Second, check the check valve inside the cylinder — contamination on the valve seat is the most common cause of lift drift and accounts for approximately 60% of drift complaints. If both the control valve and the check valve are clean and the cylinder still drifts beyond 25 mm in 10 minutes, the piston seal has internal bypass and the cylinder needs a seal kit replacement or rebuild.

How long does a forklift lift oil cylinder last?

Under normal indoor warehouse conditions with regular hydraulic oil changes, a quality lift oil cylinder typically provides 8,000–12,000 operating hours before the rod seal begins to show visible weeping. At 2,000 hours per year (single shift), that is 4–6 years. At 4,000 hours per year (double shift), 2–3 years. The first maintenance is usually a seal kit replacement at the weeping stage — which can be done in the field in 2–4 hours — extending the cylinder's life by another 4,000–6,000 hours. Full cylinder replacement (housing, rod, all internals) is typically needed at 15,000–20,000 hours when the bore surface roughness exceeds the seal's compensation range.

Can I replace just the seals instead of the whole cylinder?

Yes, if the bore surface and rod chrome are in good condition. Remove the cylinder from the mast, disassemble, inspect the bore (look for scoring, pitting, or corrosion), inspect the rod (look for chrome flaking, deep scratches, or rust pitting). If the surfaces are smooth and the chrome is intact, a seal kit replacement restores the cylinder to specification. If the bore is scored or the chrome is damaged, resealing will not fix the problem — the new seals will ride over the damaged surface and leak within weeks. In that case, the cylinder needs re-honing (bore) and re-chroming (rod), or full replacement.

What hydraulic oil should I use in the forklift?

ISO VG 32 or ISO VG 46 hydraulic oil, depending on operating temperature. VG 32 for environments consistently below 25°C (cold storage, northern climates). VG 46 for environments above 25°C (warm climates, outdoor operation, tropical regions). Never mix oil grades. Change the oil and filter every 2,000 hours or annually, whichever comes first. Oil contamination — water ingress, particulate matter, and oxidation byproducts — is the single biggest factor in hydraulic cylinder seal wear. Clean oil extends cylinder life; dirty oil shortens it.

We run 14 forklifts in a beverage distribution warehouse. Had two lift cylinders go within a month — both leaking past the rod seal after about 9,000 hours. The OEM wanted $1,400 each and 6 weeks. Got both from Ever-Power for less than half that and they arrived in under 3 weeks. Our mechanic said the finish quality on the rod is actually better than the originals. Both trucks back in service, no issues after 5 months of double-shift operation.

Replaced the main lift cylinders on a TCM FD30 triplex mast. I sent photos and measurements because the original part number was worn off. Ever-Power's engineer identified the correct spec within a day and even pointed out that my rod diameter measurement was slightly off — he was right, I had measured over a worn spot. That kind of attention to detail makes a difference. Cylinders fit perfectly.

Good cylinder. We use it in a textile warehouse. The only reason for 4 stars is that the first sample had the wrong port thread — BSP instead of metric. To their credit, Ever-Power reshipped the correct version at their own cost and it arrived in 10 days. The replacement cylinder itself is working very well, no leak after 4 months. For future orders we will double-check the port spec on the drawing confirmation before production.

Third time ordering from Ever-Power. This time was a short lift cylinder for a Hangcha CPCD25 — needed the 27-component version with sprocket. Asked for Hallite seals because we had good experience with them on the tilt cylinders we ordered last year. Everything arrived exactly as specified. The sprocket tooth profile matched the original chain perfectly. Already planning our next order — two main lift cylinders for a Clark forklift that's due for rebuild next quarter.

Simple transaction, no drama. Ordered, paid, received in 19 days. Cylinder works. That's all I need from a supplier. Will order again.