Wet Kit Installation for a Walking Floor Trailer — Ames Hydraulics

Wet Kit Installation For A Walking Floor Trailer

A walking floor trailer is a very different animal from a dump trailer. Where a dump trailer needs one big lift once per load, a walking floor needs continuous back-and-forth hydraulic flow for the entire 3-5 minutes of unloading. That changes everything about the wet kit spec — bigger pump, bigger tank, two-line configuration, and higher heat management. A wet kit installation for a walking floor trailer built with dump-trailer specs will overheat and fail within months.

Our shop is in Ames, Iowa. We install wet kits for walking floor trailer applications on Peterbilt, Kenworth, Freightliner, Mack, International, and Volvo trucks every month for owner-operators and small fleets hauling waste, grain, mulch, and processed materials.

Why A Walking Floor Needs A Two-Line System

Walking floor trailers use a series of hydraulic cylinders that push floor slats back and forth in a coordinated pattern to move the load out of the trailer. That motion requires both pressure to drive the cylinders and a return path for the return-side fluid. That’s a two-line wet kit — pressure line from truck to trailer, return line from trailer back to truck. Single-line installs cannot run walking floor trailers because there’s nowhere for the return fluid to go.

Pump Sizing Is Where People Under-Spec

A walking floor trailer running at typical unload speed needs 20-30 gpm at 2000-2500 psi continuously for the entire unload cycle. That is a significant continuous-duty flow requirement. A Parker gear pump around 30 gpm displacement is a common spec. Under-sizing the pump — which we see a lot on retrofit jobs — means the walking floor unloads slowly and the pump runs hot for the entire cycle, which shortens its life.

We spec the pump after we know the trailer’s brand and unload requirements. Keith Manufacturing, Wilson, and Trout River walking floors have different flow specs.

Tank Sizing For Continuous-Duty Applications

The walking floor’s continuous-duty operation means the tank has to hold enough oil to keep the pump fed AND give returning oil enough time to cool before it recirculates. Under-sized tanks are the second most common problem we see on wet kit installations for walking floor trailers. A 30-gallon tank that’s fine for a dump-trailer install will run hot on a walking floor. We spec 45-60 gallon tanks for walking-floor wet kits — big enough that the oil temperature stays below 180°F on the longest unload cycles.

PTO Selection

PTO selection for a walking floor wet kit installation is the same principle as any other install — match the transmission. Eaton Fuller manuals take Chelsea 442 or 852. Allison automatics take hot-shift Chelsea or Muncie. Automated manuals (DT12, mDrive, PACCAR TX-12) take their own PTO housings. The PTO output shaft must match the pump input shaft. We confirm the transmission before we spec the PTO.

Plumbing And Cooling

The pressure line, return line, and any case drain must be routed away from exhaust heat, away from moving parts, and secured against vibration. On a walking-floor wet kit we sometimes install an oil cooler in the return line — either a separate air-cooled radiator or a heat exchanger — to keep the fluid temperature down on continuous-duty unloads. That adds $300-600 to the install but adds years to the pump life.

Cost Ranges

Basic two-line wet kit installation for a walking floor trailer runs $4,500-$7,000 all-in. Add $500-1,500 for a custom-built tank. Add $300-600 for an oil cooler if the customer is unloading multiple loads per day. Retrofits (fixing a bad prior install) add $500-2,000. Every job gets a written quote before work starts.

Turnaround

A walking-floor wet kit installation is a one-to-two-week job. Bigger pump, bigger tank, more plumbing than a dump-trailer install, so it takes a little longer. If you need it faster, tell us — we can prioritize if the schedule allows.

Independent Scope

We are not a truck dealer and we don’t do warranty work. Our specialty is the hydraulic side — the wet kit itself, the PTO, the pump, the tank, the plumbing. If your truck has engine or electronic issues, the dealer network is the right place. If you need a wet kit installed for a walking floor trailer and want it done right the first time by a shop that has installed dozens, we’re the right stop.

Common Questions About A Wet Kit Installation For A Walking Floor

Can I run a walking floor on a single-line wet kit? No. Walking floors require a return line — that’s a two-line install minimum. Single-line wet kit installation for a walking floor trailer will not work.

What size tank do I need for a walking floor? 45-60 gallons is the working range. Under-sized tanks are the most common cause of premature pump failure on walking-floor wet kits.

Do I need an oil cooler with a wet kit installation for a walking floor? If you’re unloading more than one full trailer per day, yes. A return-line oil cooler keeps fluid temperature below 180°F and adds years to pump life. Adds $300-600 to the install.

How much does a wet kit installation for a walking floor cost? $4,500-$7,000 all-in for a two-line install. Add $500-1,500 for a custom-built tank. Add $300-600 for oil cooling.

Central Iowa Coverage

Our shop is in Ames, thirty minutes north of Des Moines on I-35. Owner-operators pulling walking floors from Ankeny, Boone, Marshalltown, Story City, and further out drop trucks with us regularly. Bring the truck to Ames and we can usually have you back on the road in a week to ten business days.

Get A Quote

Call or text 515-292-2599. Tell us the truck model, transmission, and the walking floor trailer you’re pulling. We’ll ballpark the wet kit installation for the walking floor trailer on the phone and firm the quote when we see the truck.