When a 2-post lift stops working, your bay stops producing revenue. Every minute that lift is down costs your shop money — in lost labor, delayed vehicles, and backed-up schedules. This 2 post lift troubleshooting guide covers the most common problems we see across Challenger, Rotary, and other brands, what causes them, and how to determine whether you can fix the issue yourself or need to call a professional.
At Auto Lift Services, we repair 2-post lifts from every major manufacturer. We have seen every failure mode on this list — from simple fixes that take 10 minutes to major rebuilds that require specialized tools and training. This guide gives you the diagnostic knowledge to identify what is wrong before you pick up the phone.
Lift Will Not Raise
This is the most common call we get, and it has the widest range of causes. Start with the simplest possibilities and work toward the more complex.
Check Power First
Before any 2 post lift troubleshooting, verify the lift has power. Check the disconnect switch — someone may have shut it off. Check the breaker at the panel — it may have tripped. Check the outlet or hardwired connection for loose terminals. A voltmeter at the motor should show 208-230V across the power leads. No voltage means the problem is electrical, not hydraulic.
Hydraulic Fluid Level
The power unit has a reservoir. If the fluid level is low, the pump cannot build pressure and the lift will not rise — or it will rise partway and stall. Check the sight glass or dipstick on the reservoir. The fluid should be at the full mark when the lift is fully lowered. Top off with the manufacturer-specified hydraulic oil (typically AW-32 or AW-46 hydraulic oil, not transmission fluid, not motor oil).
If the fluid level drops repeatedly, you have a leak somewhere in the system. Check all fittings, cylinder seals, hoses, and the power unit itself.
Motor Issues
If you hear the motor humming but the lift does not move, the motor may be running in the wrong direction (common after electrical work), the pump coupling may be broken, or the pump itself may have failed. If the motor does not make any sound at all, check the motor starter, contactor, or relay. If the motor trips the breaker immediately when engaged, the motor windings may be shorted and the motor needs replacement.
Solenoid Valve
The solenoid valve controls hydraulic flow direction. If the solenoid is stuck closed or has failed electrically, the pump will run but no fluid flows to the cylinders. You can sometimes hear the solenoid click when the raise button is pressed — no click usually means a failed solenoid coil. Replacement solenoid valves are available for all major brands.
Uneven Lifting — One Side Higher Than the Other
Uneven lifting is a serious safety concern. If one side rises faster or higher than the other, the vehicle tilts and can slide off the arms. Stop using the lift immediately and diagnose the cause.
Cable Equalization
Most 2-post lifts use steel cables to synchronize the two columns. Over time, cables stretch at different rates, causing one side to lead or lag. This is the most common cause of uneven lifting and the most straightforward fix in 2 post lift troubleshooting.
The equalization adjustment involves loosening the cable adjusters, raising the lift empty, measuring the carriage heights on both sides, and adjusting until both sides are within 1/4 inch. This should be part of regular maintenance — check equalization monthly in high-volume shops.
Cylinder Problems
If cables are equalized but the lift still rises unevenly, one cylinder may be leaking internally. Internal leaks allow fluid to bypass the piston seal, causing that side to rise slower or drift down after raising. A cylinder with internal bypass needs a seal kit or full rebuild.
Restriction in Hydraulic Lines
A kinked, pinched, or internally deteriorated hydraulic hose on one side restricts flow and causes that side to rise slower. Inspect all hoses for external damage, check fittings for tightness, and look for signs of internal breakdown (rubber particles in the fluid).
Lift Will Not Lock
The locking mechanism — typically a pawl-and-ladder or pin-and-column system — engages automatically as the lift rises to hold it at working height. If the locks do not engage, the lift is unsafe to work under.
Lock Pawl Wear
Lock pawls are hardened steel components that engage notches in the column. Over thousands of cycles, the engaging edges wear and may no longer catch properly. Worn pawls need replacement — they are not repairable. This is a common 2 post lift troubleshooting item on lifts with 10 or more years of service.
Air Supply Issues
Lock release on most 2-post lifts requires compressed air. If your shop air pressure drops below the minimum (typically 100-175 PSI), the locks may not disengage properly on the way down, or the release mechanism may not function. Check your compressor output, regulator setting, and air line for leaks or restrictions.
Lock Timing
The lock mechanism is timed to engage at specific intervals as the lift rises. If the timing is off — often caused by misadjusted cables, worn pawl springs, or debris in the lock mechanism — the pawls may skip engagement positions. Cleaning, lubrication, and spring replacement usually restore proper lock timing.
Slow Rise
A lift that takes significantly longer to reach full height than when it was new has a hydraulic system issue that will progressively worsen.
Low Fluid
The first check in any slow-rise 2 post lift troubleshooting scenario is fluid level. Low fluid starves the pump and reduces flow volume to the cylinders. Top off and test.
Worn Pump
Hydraulic pumps have internal gears or vanes that wear over time. As clearances increase, the pump moves less fluid per revolution. Flow drops, pressure may decrease, and rise time increases. A pump that takes 60 seconds to raise the lift when it took 35 seconds new is showing its age. Pump replacement or rebuild restores original performance.
Restricted Flow
Check the hydraulic filter (if equipped), intake strainer, and all hose connections for restrictions. A clogged filter or collapsed intake hose reduces flow to the pump. Contaminated fluid with particles or sludge can restrict flow throughout the system.
Undersized Electrical
Voltage drop on long wire runs or undersized circuits reduces motor speed, which reduces pump speed, which reduces flow. Measure voltage at the motor while the lift is running — it should be within 10 percent of nominal (208-230V). If voltage drops below 190V during operation, the circuit needs upgrade.
Drift or Sinking — Lift Drops Under Load
If a raised lift slowly settles downward with a vehicle on it, this is a critical safety issue. Lock the lift on safety stands immediately and do not use it until the cause is found and fixed.
Cylinder Seal Failure
The most common cause of drift is worn piston seals in the hydraulic cylinders. Fluid bypasses the seal under the weight of the vehicle, allowing the cylinder to retract slowly. A cylinder seal kit is the fix — this involves removing the cylinder, disassembling it, replacing the seals, and reassembling.
Check Valve Failure
The check valve in the hydraulic circuit prevents fluid from flowing back to the reservoir when the pump stops. A worn or contaminated check valve allows bleed-back, causing the lift to slowly sink. Check valve replacement is a straightforward repair once the correct part is identified.
Fitting Leaks
A slow external leak at any fitting, hose connection, or cylinder port allows fluid to escape, gradually lowering the lift. Inspect all connections for weeping or dripping. Tighten fittings to spec or replace damaged fittings and O-rings.
Noise Problems
Pump Cavitation
A high-pitched whining or screaming sound from the power unit usually indicates pump cavitation — the pump is pulling air instead of fluid. Causes include low fluid level, clogged intake strainer, air leak in the suction line, or fluid that is too thick (wrong viscosity or extremely cold shop). Fix the root cause and the noise stops.
Grinding or Clicking
Grinding sounds from the columns indicate worn carriage rollers or guides. Clicking sounds during operation may indicate loose bolts, worn cable sheaves, or debris in the lock mechanism. Each sound has a specific cause — a lift technician can usually diagnose the source in minutes with the lift running empty.
Loose Bolts
Vibration during operation can loosen anchor bolts, column bolts, overhead beam bolts, and arm pivot bolts over time. A periodic torque check of all fasteners is basic maintenance that prevents noise, reduces wear, and maintains structural integrity.
Hydraulic Leaks
External hydraulic leaks are visible — you will see fluid on the floor, on the columns, or dripping from fittings. Trace the leak to its source by wiping the area clean and running the lift through a cycle.
Common leak points: cylinder rod seals (fluid weeping around the rod where it exits the cylinder), hose fittings (fluid at threaded connections), power unit seals (fluid under the power unit), and the lowering valve (fluid dripping from the valve body). Each requires different repair — seal replacement, fitting tightening, or component replacement.
When to Call a Professional
Some 2 post lift troubleshooting items are safe for shop personnel to handle: checking fluid level, checking power, tightening fittings, adding hydraulic oil, and cleaning lock mechanisms. These do not require specialized training.
The following require a qualified lift technician: cylinder rebuilds, pump replacement, cable replacement and equalization, structural repairs, lock mechanism rebuilds, anchor remediation, and any situation where the lift has dropped or shifted under load. These repairs involve heavy components, high-pressure hydraulics, and safety-critical systems that must be restored to manufacturer specifications.
Call 800-674-9302 or email info@autoliftserv.com for lift repair service. We service all major 2-post lift brands nationwide and can usually respond within 24 to 48 hours. Parts and lifts available at store.autoliftserv.com.
Josiah Ragsdale
Founder, Automotive Lift Services
Josiah has been installing, repairing, and inspecting automotive lifts since he was 18 years old. He founded Automotive Lift Services in 2019 after years of seeing lifts installed wrong, never inspected, and putting technicians at risk. His team now services all 50 states from their Iowa headquarters. Read more
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