Puddle under the machine, a platform that sinks overnight, or a lift that’s suddenly slow and weak? That’s hydraulics — and it’s the kind of repair you want done in a shop, not patched in a parking lot. We diagnose and rebuild scissor lift hydraulic systems at our Addison, IL shop: cylinders, pumps, valves, hoses, and the leaks and drift that come with them. We pick your lift up and diagnose it the same day. Call 773-790-7299. Genie, Skyjack, and JLG.

What we fix

• Lift cylinders — reseal or replace; gland seals, wear rings, and the o-rings between cylinder and holding-valve manifold
• Pumps and motors — worn gear pumps that can’t build pressure anymore
• Valves — lift, lowering, holding, relief, and steer valves; sticking, leaking, or out of adjustment
• Hoses and fittings — replaced to spec torque, not just snugged up
• Fluid service — the right oil (Genie machines: AW46; Skyjack: ATF), filter, and a system flush when contamination is the real culprit

Common hydraulic symptoms — what they usually mean

Platform drifts down overnight. Some settle is normal; visible sink over a few hours is not. On most machines it’s the lift cylinder gland seal, or the holding/lowering valve stack not sealing, or the o-ring at the cylinder-to-manifold joint. A cylinder that bypasses internally won’t hold — no amount of valve work fixes a worn cylinder.

Won’t lift, or lifts slowly. First the cheap stuff: a manual lowering valve left open, low fluid, an overloaded platform. Then pressure — a tired pump or a relief valve dumping early. We test actual system pressure against spec rather than guessing.

Fluid on the floor. Trace it to the source — a hose, a fitting, a cylinder rod seal, or the manifold. A puddle is cheap to fix early and expensive to ignore; run a machine low on oil and you’ll be buying a pump.

Everything sluggish. Often fluid condition — contaminated or wrong-viscosity oil, or a clogged filter — before it’s a component. Cold weather with the wrong oil grade does this too.

Why hydraulic work belongs in the shop

Hydraulic diagnosis needs pressure gauges, the right fittings, clean conditions, and a way to safely support an elevated platform while you work under it. It also needs the parts — seals, cylinders, valves — on the shelf. That’s a shop, not a truck box. We diagnose it right, quote it before we start, and function-test the machine through its full range before it goes back. No patch work.

Pricing

Hydraulic repairs run $150/hr plus parts, quoted after same-day diagnosis and approved by you before any work begins. If a cylinder or pump makes the repair uneconomical on an older machine, we’ll tell you straight and show you a refurbished replacement. Pairs naturally with the annual inspection while the machine’s already here.

Hydraulic repair FAQ

My scissor lift drifts down — is that dangerous?
A slow settle is normal; a platform that visibly sinks needs attention before someone’s working off it. It’s usually a seal or valve, and it’s a repair, not an adjustment.

What hydraulic oil do these machines use?
Genie scissors run AW46 (their manual references an ISO 32 AW-type oil); Skyjack runs ATF Dexron III. Using the wrong oil, or mixing types, causes its own problems — we use the right fluid for your machine.

Can you reseal a cylinder or does it need replacing?
Depends on the bore. If the cylinder wall is scored or worn, resealing won’t hold and replacement is the honest fix — we’ll tell you which after we open it up.

There’s oil under my lift but it still works — can I keep using it?
Don’t. Running low on fluid damages the pump, and a leak only gets worse. Get it in before a cheap seal becomes an expensive pump.

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Get your hydraulics fixed right: call 773-790-7299 (Mon–Fri 7am–3pm) or request service online. Also see: service hub · annual inspection · Genie · Skyjack · JLG service.