Your Semi Truck Is Your Livelihood — Treat It That Way
You know the feeling. A dash light flickers on somewhere past the last exit, and your gut drops before your brain even catches up. Every hour that rig sits is money you’re not making — a load that doesn’t move, a customer who starts calling around, a crew standing idle waiting on you. When a semi goes down, it doesn’t just cost you a repair bill. It costs you the whole day, sometimes the whole week.
Note: Large vehicles like this are serviced at our Greeley and Fort Morgan locations. Our Brighton shop handles cars and light trucks.
That’s exactly why Bullet Automotive & Diesel exists. From our shop at, with locations in Greeley and Fort Morgan, CO, our ASE Certified Technicians work on Freightliner, Peterbilt, Kenworth, Volvo, International, Mack, Western Star, and Hino trucks every single week. We shoot straight — a plain-English diagnosis, an honest priority list, and a real answer on how fast you’ll be rolling again. No dealership runaround. No mystery line items.
Why Semi Truck Owners in Greeley and Fort Morgan Choose Bullet Automotive & Diesel
We Speak Your Language, Not Mechanic Jargon
You’ve been around engines long enough to smell a snow job. So we don’t give you one. When your truck comes in, you get a clear rundown of what’s actually wrong — what has to be fixed for safety, what’s coming soon, and what can wait until the budget allows.
- A plain-English explanation of the problem, not a code you have to Google
- A three-tier priority list: safety now, coming soon, down the road
- Comprehensive multi-point vehicle inspections so nothing sneaks up on you
- Straight answers on downtime before we start the work
You’ll never leave here feeling talked down to. If you want to know exactly why a part failed, we’ll show you the old one and walk you through it.
Semi Truck Expertise Without Dealership Pricing
Truck dealerships treat you like a walking wallet and book you out days in advance. We’re built different. With true diesel experience and heavy-duty diagnostic equipment like and TEXA, we handle big-bore engines and complex aftertreatment systems without the dealer markup.
- Heavy-duty diesel diagnostic tools for Cummins, PACCAR, Detroit, and more
- Fleet maintenance repair specialists who understand uptime pressure
- Quality parts sourced to match how hard your truck works
- convenient locations across the Front Range and eastern plains
You get dealership-level capability from technicians who actually remember your name and your truck.
Transparency That Rebuilds Trust
You’ve been burned before. Maybe a shop found ten new problems the moment you dropped the keys, or a cheap garage missed the real issue and you were back in two weeks. We won’t do that to you.
- Written estimates before any wrench turns
- No surprise line items added to the bill
- We only recommend what your truck actually needs
- Backed by our 12 month or 12,000 mile warranty on qualifying repairs
Over 800 5-star reviews came from owners who were tired of guessing whether they got played. Now they’ve got a shop on speed dial.
Comprehensive Semi Truck Repair Services in Greeley and Fort Morgan
Semi Truck Maintenance Services
Preventive maintenance is the cheapest insurance a working truck can buy. Colorado’s punishing temperature swings — below freezing in the morning, well over 100 by afternoon — and the elevation changes from the Denver metro to the mountains beat on every fluid, seal, and belt you run.
- Diesel oil changes and filter service on manufacturer intervals
- Fuel filter and water separator replacement
- Coolant system flushes and DEF system checks
- Air system and brake inspections
- Greasing chassis, kingpins, and drivetrain components
- Scheduled fleet maintenance built around your route calendar
- Belt, hose, and battery inspection before they strand you
Talk to us about a scheduled maintenance plan that keeps your rig ahead of trouble instead of chasing it.
Semi Truck Diagnostic and Repair Services
When something breaks, you need a real diagnosis fast — not a parts-cannon guessing game. Our heavy-duty diagnostics pinpoint the fault the first time.
- Diesel engine repair and rebuild
- Check engine light and fault code diagnosis and repair
- Air and hydraulic brake repair
- Clutch, transmission, and drivetrain repair
- Electrical and charging system troubleshooting
- Suspension, steering, and alignment repair
- Cooling system and radiator repair
For deeper diesel work, our full diesel repair services cover everything from injectors to turbochargers.
Semi Truck Specialty Services
Modern semis carry emissions and aftertreatment systems that stump most general garages. We don’t flinch at them.
- DPF cleaning and replacement
- EGR valve service and diesel emissions repair
- Turbocharger repair and replacement
- Fuel injector cleaning and replacement
- Lift gate and trailer repair coordination
Whatever brand of iron you run, we’ve seen it in the bay before.
Model-Specific Semi Truck Expertise
Freightliner Cascadia Service and Repair
The Cascadia is the workhorse of American long-haul, and the Detroit DD13 and DD15 engines under those hoods are what most Colorado fleets run. We handle aftertreatment faults, DEF dosing issues, and the electrical gremlins these trucks are known for, keeping your Cascadia moving loads instead of parked in a bay.
Peterbilt 379 and 389 Service and Repair
Peterbilt owners take pride in their trucks, and we get it. Whether you run a classic 379 or a newer 389 with a PACCAR MX engine, we service the driveline, suspension, and cooling systems that take a beating hauling through the mountains. Straight talk, quality parts, and repairs that hold.
Kenworth T680 and W900 Service and Repair
Kenworth’s T680 aero trucks and the legendary W900 both come through our doors. We diagnose PACCAR MX-13 issues, chase down HVAC and electrical faults, and keep the air brakes and suspension tight so your Kenworth stays reliable mile after mile.
Volvo VNL Service and Repair
Volvo’s VNL pairs comfort with the D13 engine, and its integrated systems demand real diagnostic capability. We service the I-Shift transmission, aftertreatment, and cooling systems, and we speak the fault codes fluently so your Volvo isn’t sidelined waiting on a dealer appointment.
International LT and ProStar Service and Repair
International trucks running the Cummins X15 or International A26 are common across our service area. We handle emissions system faults, fuel system repairs, and the electrical diagnostics these trucks need, getting your LT or ProStar back to earning.
Mack and Western Star Service and Repair
Mack Anthem and Western Star trucks earn their keep in vocational and heavy-haul work. We service Mack MP engines and Western Star’s Detroit powerplants, handling everything from driveline wear to cooling system repair so these heavy hitters keep pulling.
Common Issues Across Semi Truck Models
No matter the badge on the hood, heavy-duty trucks share a set of predictable trouble spots. Catching them early is the difference between a scheduled fix and a roadside breakdown.
- DPF and aftertreatment clogging: Regen problems and derate warnings pile up when the diesel particulate filter loads up; we clean or replace the DPF and clear the underlying fault.
- EGR and emissions faults: Sticking EGR valves and DEF dosing errors trigger check engine lights and power loss; we diagnose the root cause instead of just clearing codes.
- Turbocharger failure: Loss of power and excessive smoke often trace back to a worn turbo; we rebuild or replace it and check the oil supply that killed the last one.
- Cooling system overheating: Colorado grades and 100-plus-degree summers push cooling systems hard; we repair radiators, water pumps, and coolant leaks before they cook an engine.
- Air brake and system leaks: Slow air buildup and dragging brakes are safety issues we don’t let slide; we find the leak and restore proper braking.
- Electrical and charging faults: Dead batteries and intermittent gremlins strand trucks fast; we trace the circuit and fix the actual problem, not the symptom.
The Bullet Automotive & Diesel Difference for Semi Truck Owners
You’re not looking for the cheapest shop in town. You’re looking for the one you never have to second-guess — for this truck and for the rest of your fleet.
- Respects your time with efficient service and honest downtime estimates
- Respects your wallet with written estimates and no surprise upsells
- Respects your knowledge by explaining repairs in plain English, never talking down
- Respects your business with fleet maintenance built around keeping you rolling
The goal isn’t one repair. It’s becoming the shop you call for years — the one that quiets that low hum of worry every time your truck makes a noise you don’t recognize.
Service Areas We Serve
Owner-operators and fleets across the Front Range and eastern plains trust us with their semi truck repair and maintenance.
- Greeley and Fort Morgan, CO — our home shop in Greeley and Fort Morgan
- Greeley, CO — full diesel service for northern Colorado haulers
- Fort Morgan, CO — heavy-duty repair for the I-76 corridor
- Fort Lupton, CO — trusted by local contractors and fleets
- Commerce City, CO — convenient for distribution and freight runs
- Henderson, CO — quick access for working trucks nearby
Schedule Your Semi Truck Service Today in Greeley and Fort Morgan, CO
When your rig is down, every hour counts — so let’s get it diagnosed right and back on the road. Bullet Automotive & Diesel gives you the straight answer, the honest priority list, and repairs that hold up to real work.
Bullet Automotive & Diesel
Greeley: 624 13th St., Greeley, CO 80631 · 970-415-8018
Fort Morgan: 100 Walnut St., Fort Morgan, CO 80701 · 970-867-2519
See what other owners are saying on our reviews page, then call us. We always shoot straight — call 970-415-8018 to get your semi scheduled.