Install Prep and Site Survey for Automotive Two Post Lifts: A Marion Fleet Walkthrough

A municipal fleet manager in Marion called us because his crew was doing annual state inspections on tandem-axle plow trucks, squad cars, and pickups in the same two bays, and one of his automotive two post lifts had a lock that was engaging late. That call turned into a full site survey, because when we walked the shop we found three separate issues that had nothing to do with the lock. This article is that walkthrough, written out in the order we do it — safety first, then measurements, then the paperwork. If you’re preparing a bay for new equipment or trying to figure out why an existing setup feels sketchy, this is the same checklist we bring with us on every visit.

Start With the Ceiling, Not the Floor

Everybody measures the floor first. We start by looking up, because ceiling height is the constraint that kills the most projects and it’s the one you can’t fix. A clearfloor overhead two-post needs enough room for the overhead beam plus the rise you actually want, and on a lot of municipal buildings there’s a truss bottom chord, a unit heater, a sprinkler main, or a bank of light fixtures sitting exactly where the beam wants to go. In Marion the shop had a nominal 14-foot ceiling that was really 12 feet 4 inches to the bottom of an HVAC duct run right down the center of the bay.

That single measurement redirected the whole conversation. With that duct in place, a clearfloor overhead unit was out unless they wanted to relocate mechanical, which for a city budget cycle means next fiscal year at the earliest. So we went baseplate. A baseplate two-post carries the equalization and hydraulic lines in a floor-mounted cover between the columns, which means no overhead structure and no height penalty — you just live with a low ramp-over between the posts. For a fleet doing annual state inspections, that trade is usually easy, since techs are walking around the vehicle with a light and a pry bar rather than rolling heavy toolboxes across the bay. When we spec automotive two post lifts for older municipal buildings, baseplate wins more often than people expect. We had a customer in North Dakota reach the same conclusion for the same reason — he had a hard 139-inch height ceiling and knew going in that overhead wasn’t happening.

Coring the Slab and Reading What You Find

The second thing we do is drill. Not a full core rig on every job, but at minimum a hammer drill with a marked bit at each proposed column location so we know actual thickness, and a rebound hammer or a core sample if the numbers look marginal. Manufacturer specs are typically four to six inches of 3,000 PSI concrete for lighter units and six inches or more for heavier capacities, measured as unreinforced thickness with adequate spacing from joints and edges.

What we found in Marion was informative. The bay floor tested a solid six and a half inches — good news — but one of the existing columns had been anchored eleven inches from a control joint, and the concrete around three anchors had spalled into a visible cone. That’s the classic signature of anchoring too close to a joint or edge: the anchor pulls a wedge of concrete instead of holding. The lock timing complaint the fleet manager called about was real, but the anchor condition was the actual safety issue. We’ve seen the same thing on a shop floor in northern Missouri where the owner thought he had five inches and it turned out to be closer to three in spots because the sub-base had settled before the pour. Test, don’t assume. Core samples cost almost nothing compared to relocating automotive two post lifts after they’re standing, and they give you documentation your risk manager will actually want to see.

Bay Width, Column Spacing, and the Vehicle Mix

Now the floor plan. A two-post needs its column spacing plus working room on both sides plus door swing clearance for the widest vehicle you’ll actually lift. For a fleet that means measuring your worst case, not your average. The Marion shop’s mix ran from compact squad cars up to a single-axle dump with a plow frame, and the plow frame was the governing dimension for approach width even though the truck itself wasn’t the widest thing in the fleet.

We mark column locations on the floor in tape and then physically walk the biggest vehicle in, or as close as we can get, before anything is drilled. That fifteen-minute exercise catches problems drawings never will — a floor drain right where an anchor goes, a compressor line at knee height, a wall-mounted parts washer that eats eight inches of the passenger side. For symmetric versus asymmetric, the vehicle mix decides it. Symmetric columns face each other squarely and center the vehicle between them, which suits trucks and vans. Asymmetric rotates the columns and uses uneven arm lengths so the vehicle sits back, giving you door clearance on cars. Fleets with a genuinely mixed population often do better with one of each rather than two identical bays. That’s how we ended up configuring their automotive two post lifts — one symmetric for trucks, one asymmetric for the car side. See our article on symmetric vs asymmetric two-post lifts for a deeper comparison.

Electrical and Air: What to Rough In Before Delivery

Once column locations are final, the electrical and air rough-in happens before the equipment shows up. Almost every single-bay power unit we install runs 208-230V single phase on a dedicated 20 to 30 amp circuit, though three-phase versions exist and make sense if a shop already has it distributed. The disconnect goes within sight of the power unit. The conduit stub comes up where the power unit column actually lands, based on the manufacturer’s anchor drawing, not a rough guess.

Air is the piece fleet shops underestimate. On most modern two-post designs the lock release is air-actuated, so no air means no lowering. In a municipal shop where the compressor gets shut off nightly and the receiver bleeds down, that’s an operational annoyance at best and a stuck vehicle at worst. We spec a half-inch drop with a filter, regulator, and quick-disconnect within arm’s reach of the power unit column, and we tell shops to verify the compressor can maintain pressure through a full day of impact gun use during inspection season. While the electrician is in there, add lighting. Annual state inspections mean crawling under a vehicle looking for frame rot and brake line corrosion, and a pair of bay lights positioned outside the lift footprint saves an enormous amount of squinting. Getting all of this staged before delivery is the difference between a one-day install and a three-visit project. Our install crews will happily send a marked-up drawing to your electrician before anything on the automotive two post lifts order ships.

The Safety Walkthrough We Do Before Sign-Off

Installation isn’t finished when the columns are plumb. We run a fixed sequence before we hand over a bay. Anchors torqued to spec with a calibrated wrench, and the shim stack under each column base within the manufacturer’s allowable limit. Columns plumb within tolerance both directions, checked with a laser. Equalization cables adjusted so both carriages arrive at every lock position simultaneously — this is the one that catches shops off guard, because a half-second offset feels fine empty and feels awful with 9,000 pounds up.

Then hydraulics: bleed the cylinder, cycle the unit five times unloaded, check for weeping at the fittings and the rod seal. Then the safety systems: every lock engages audibly at every position, the automatic arm restraints lock and release properly, and the overhead or floor-mounted shutoff functions. Finally a loaded cycle with a real vehicle, up and down, listening. Then paperwork — anchor torque values, concrete thickness readings, serial numbers, and a copy of the operator manual mounted at the bay. For a municipal fleet that documentation isn’t optional; it’s what a risk manager and an OSHA inspector both ask for. We repeat a shortened version of this walkthrough on annual inspections, and it’s how we catch worn arm pins and frayed cables before they become incidents. Our piece on annual two-post inspection covers the recurring version.

Training the Crew Who Will Actually Use It

The best-installed lift in Iowa will get abused if nobody shows the techs how it’s meant to work. In fleet shops especially, turnover means someone who’s never touched this brand will be loading a truck on it within a month. We spend the last part of every install with whoever’s available, walking through pickup points, arm adjustment, and the lock sequence.

Three habits matter more than everything else combined. First, set the pads on manufacturer-designated lift points, not on a rocker panel or a plastic running board — plow trucks and squad cars both have frame points that are obvious once someone points them out and invisible otherwise. Second, raise until the tires clear, then stop, shake the vehicle firmly, and only then go to working height and lower onto the locks. Every single vehicle-off-lift incident we’ve been called about traces back to skipping that shake test. Third, always lower onto a lock before going underneath, and never work under a unit that’s holding on hydraulics alone. We also cover daily visual checks: look at cables for broken strands, look at the floor for fresh oil, look at the arm restraints. Thirty seconds a day. Fleet shops that build these habits get twenty-plus years out of their equipment. If you’re in Marion, Cedar Rapids, or anywhere in eastern Iowa and want us to survey your bays or quote automotive two post lifts, call 800-674-9302 and we’ll come measure.