The 4 Post Lift Inspection Checklist We Use on Every Service Call

A good 4 post lift inspection checklist takes about twenty minutes and can save you a runway, a cable set, or a whole lot worse. We’re Auto Lift Services out of Ames, Iowa, and between installs and service calls we put eyes on four-post lifts in home garages, municipal shops, fleet buildings, and dealership service bays across the state every single week. What we’ve learned is that almost nothing on a four-post fails without warning. Cables fray strand by strand. Sheaves wobble before they seize. Lock latches get lazy long before they stop catching. The trouble is that nobody looks until something bangs, so below is the exact sequence we walk, in the order we walk it, with the things we actually find.

Start on the Floor, Not on the Lift

Every inspection we do starts with a walk around the base of all four columns before anything moves. We’re looking at anchors first: are all the bolts present, are the nuts tight, is there any daylight or dust cone around the anchor sleeve that says the bolt has been working in its hole? On a four-post that isn’t anchored — and plenty of home installs legitimately aren’t required to be — we’re checking that the feet sit flat and that nobody has shimmed a column with a stack of washers and a prayer. Then we look at the concrete itself. Spider cracks radiating from a base plate mean the slab is talking to you, and in older Iowa shops with 4-inch pours and no rebar, that’s a conversation worth having before you park a three-quarter-ton truck twelve feet up.

Next comes housekeeping, which sounds soft until you’ve seen what it causes. We sweep under the runways and out of the column bases, because packed dirt and shop debris in a column channel will chew a slider block and throw a runway out of level. We check that the drive-on approach ramps latch and stow, that the wheel chocks are still on the lift instead of holding a shop door open, and that nothing is stacked against a column. A tidy footprint is genuinely the first item on our 4 post lift inspection checklist because it’s the cheapest problem on the list to fix.

Cables Are the Item That Actually Kills Four-Posts

If you only do one thing on this list, do this one. A four-post lift hangs its runways on four equalizer cables, and those cables are the single most common reason we get called out to a lift that’s suddenly sitting crooked. We run a gloved hand — leather, not cotton — along every accessible inch of every cable, slowly. What we’re feeling for is broken strands, the little wire barbs the industry calls fishhooks. One broken wire is a note in the logbook. Several in one lay length, or any breakage at a termination or where the cable rides a sheave, and that cable set comes off. Cables get replaced as a set, all four, never one at a time, because the three survivors have already stretched and you’ll be chasing level forever if you mix old and new.

We also check the terminations at the top of each column: cotter pins present, jam nuts tight, thimbles not deformed. Then we look for corrosion, especially in unheated pole barns where humidity swings hard in the spring. Surface rust that wipes off is fine; rust that has bloomed into flaky scale under the strands is not, because the wire underneath is already thinned. Our two-post work uses the same discipline, and if you want the parallel version we keep a two-post lift cable inspection checklist that goes deeper on wear patterns and lay length math.

Sheaves, Pulleys, and the Sounds They Make

Cables don’t wear out on their own — they wear out over bad sheaves. Every four-post has sheaves at the top of the columns and usually more under the runways, and each one needs to spin free with no side play. We put a finger on the axle and rock the wheel. If it clunks, the bushing is gone. We look into the groove for a shiny witness mark that has gone from a smooth U into a sharp V, because a worn groove pinches the cable and grinds it from the inside out. Any sheave with a chipped flange, a flat spot, or grooving deep enough to feel with a fingernail gets swapped.

The other half of this step is listening. We cycle the lift empty, all the way up and all the way down, and just stand there. A healthy four-post makes a consistent sound. A dry sheave chirps at one point in the travel. A cable riding a flange makes a rhythmic tick. A bad slider block gives you a stick-slip groan under the runway. We note where in the travel the noise happens, because that tells us which sheave to pull without disassembling the whole lift. Adding this listening pass to your 4 post lift inspection checklist catches problems weeks before they show up as a level issue.

Lock Latches, Ladders, and the Slack Safety System

The locks are what hold the vehicle, and the slack safety is what catches you if a cable lets go. Both get tested, not just looked at. We raise the empty lift and lower it onto each lock position in turn, listening for four crisp clicks — one per column — as the latches drop in. A lazy latch that hesitates or needs a nudge is usually a stretched return spring, a dry pivot, or a bent lock rod, all cheap parts. We inspect the lock ladders themselves for elongated or mushroomed notches, and we check that the release mechanism pulls all four at once instead of three-and-a-half.

Then the slack safety. On most four-posts there’s a spring-loaded arm at each cable termination that drops a pawl into the ladder if cable tension is lost. We take tension off one cable at a time, carefully, and verify the safety engages. If it’s rusted in the retracted position it is a decoration, not a safety, and we’ve found plenty like that on lifts that hadn’t been serviced in a decade. This is also the point where we check the air line and valve if the lift uses air-release locks, since a leaking line drains a compressor and can hold locks partly open. Anyone maintaining both lift types will recognize the pattern from our two-post lift safety inspection checklist.

Hydraulics: Cylinder, Hoses, Fittings, Fluid

Four-posts are usually single-cylinder, which is a mercy — one cylinder, one power unit, a handful of hose runs. We start at the power unit and check fluid level with the lift fully down, because checking it up gives you a false low and people overfill, then wonder why fluid weeps out the breather. We look for wetness at the pump-to-reservoir joint, at every hose fitting, and along the cylinder rod. A rod that’s damp after a cycle is a seal starting to talk; a rod that’s dripping is a rebuild. Any hose with cracked cover, kinks, or abrasion where it rubs a runway gets replaced, and we route it so it can’t rub again.

We also watch the lift for drift. Raise it to mid-travel, shut the pump off, mark the runway height, and come back in fifteen minutes. Slow settling points at the lowering valve, the cylinder seals, or a leaking check. That’s why every four-post is meant to rest on its mechanical locks and not on hydraulic pressure — a step people skip and then blame the lift. Recording drift measurements on the same 4 post lift inspection checklist month after month gives you a trend line instead of a guess.

Runways, Level, and Structural Welds

With the lift down, we walk the runways looking underneath at the crossmembers and welds. Cracks show up as rust lines running out of a weld toe, and they show up most often near the ends where the runway takes the load of a vehicle driving on. We check the runway surface for dishing or oil-can flex, verify the deck plates and jack tray rails are secure, and confirm the rolling jack — if the customer has one — rolls smoothly and its saddle isn’t cracked.

Then we level it. Raise to a comfortable working height and put a level across both runways front and rear, and diagonally corner to corner. Anything more than a small deviation means the cables want adjustment at the column tops, and on a lift that’s been in service a few years, one round of equalization often solves a mystery clunk at the same time. We also confirm the runways come up together, not one end leading, and that both stop at the same lock position. If you’re evaluating a lift you didn’t buy new, the mindset in our used two-post lift inspection checklist transfers directly — assume nothing, verify everything, and price the parts you’ll need before you hand over money.

How Often, Who Signs It, and What We Charge For

Our recommendation matches ANSI/ALI practice: a quick daily visual by whoever uses the lift, a documented monthly check, and an annual inspection by a qualified inspector. In a busy shop we’ve watched a quarterly cadence catch cable wear that a yearly-only schedule would have missed by six months. In a home garage that lifts a project car twice a month, monthly is honestly overkill — but the annual is not, because the failures we see there are corrosion and neglect rather than cycles.

Write it down. A dated log with initials is what protects you if an insurer or an OSHA inspector asks, and it’s what lets us walk in cold and see history instead of guessing. We keep four-post cables, sheaves, lock springs, slider blocks, and cylinder seal kits on the shelf here in Ames, so a failed item usually doesn’t mean a lift down for weeks. If you’d like us to run the full 4 post lift inspection checklist on your equipment, or you just want a second opinion on a cable you’re not sure about, call us at 800-674-9302 and send a photo. We’d rather talk you through it for free than replace a runway later.

Related: two post lift inspection checklist