Frequently Asked Questions

We specialize in heavy-duty commercial trucks and diesel engines — the tractors, straight trucks, and fleet vehicles that businesses depend on. Our technicians focus on commercial diesel equipment, from major engine work to emissions systems and roadside repairs.

Yes. We handle complete heavy-duty engine rebuilds and major repair in our Sumner facility — full teardown, inspection, precision machine work, and reassembly with OEM-grade components, backed by complex diagnostics.

Absolutely. We provide DPF cleaning and flow testing, aftertreatment and DEF diagnostics, forced regen and derate resolution, and EGR/SCR/sensor repair to keep your trucks compliant and out of derate.

Yes. We run complex driveability and electrical diagnostics either in the shop or on-site, pinpointing the real problem before any parts are ordered so you're not paying to guess.

We can. Scheduled preventive maintenance is the single biggest lever on uptime — it turns surprise breakdowns into planned service. We keep records on your trucks so issues get caught early and fleet planning gets easier each season.

Yes. Our mobile units bring diagnostics and emergent repairs to your yard or the roadside across the Greater Seattle area, cutting towing time and getting drivers moving again fast.

Call us at (206) 304-6870. Tell us where you are, what you're running, and the symptoms. If the truck can't make it to the shop, we'll work to get a mobile unit to you and get you the fastest path back on the road.

Major work like engine rebuilds is best handled in our Sumner shop, where we have the equipment and controlled environment for it. Diagnostics and emergent repairs can often be done on-site. Call us and we'll point you to the right option.

Yes. Our Sumner shop does full frame-up custom builds as well as the individual pieces: custom engine builds from 500 to 1,200 horsepower depending on application, engine swaps, custom air ride kits and custom cab and sleeper flooring. Everything is planned together and built by the same crew.

Our custom engine builds range from 500 to 1,200 horsepower depending on the application. Long-haul reliability sits at one end of that range and heavy-haul or show builds at the other — the job decides the number, and the cooling, fuel and drivetrain get matched to it.

Yes. Most builds are staged so the truck keeps earning between phases — engine and suspension first, interior and finish later, for example. We plan the order so early work never has to be undone.

We design and install custom air ride kits — bags, tanks, valves, lines and controls — and set ride height and leveling to the truck. We also repair existing air suspension: leaking bags, failed leveling valves and worn shocks.

We're located at 15022 Puyallup St #101, Sumner, WA 98390.

Our hours are Monday – Friday 9:00 AM – 5:00 PM, Saturday 10:00 AM – 3:00 PM, Sunday Closed. For roadside breakdowns, call first and we'll get you the fastest available help.

We're based in Sumner, WA and serve the Greater Seattle area and the wider South Sound, including Sumner, Puyallup, Tacoma, Fife, Auburn, Kent, Federal Way, Renton, Seattle, Bellevue. If you run commercial trucks in the region, we can help.

Call us at (206) 304-6870 or send a message through our contact form. Tell us the truck, the symptoms, and your timeline, and we'll respond with a straight answer and a fair quote.

Yes. Emerald Fleet Services is family-owned and operated. When you call, you deal with the people who own the shop and stand behind the work — not a corporate service desk.

Owner-operators first. Most of the trucks in our shop belong to the driver who runs them, and our custom build work is built around individual trucks. We work with fleets too — whether you run one truck or twenty, our focus is keeping you on the road and earning.

Stay ahead of failures with preventive maintenance, get fast and accurate diagnostics, and use mobile service to avoid unnecessary tows. Every decision we make is built around getting your trucks back to work quickly.