Your Mack Truck Deserves More Than Just Another Repair Shop
It’s 5 a.m., you’ve got a load waiting and a crew counting on you, and your Mack won’t build air. Or the check engine light flickers on somewhere between the shop and the job site, and you feel that familiar knot in your stomach. Every hour that truck sits idle is money leaking out of your pocket, and you already know how that quote at the dealer is going to read. You need someone who works on your Anthem, Granite, Pinnacle, or CHU day terminal-tractor and gives you the real story, not a padded invoice.
Note: Large vehicles like this are serviced at our Greeley and Fort Morgan locations. Our Brighton shop handles cars and light trucks.
That’s where Bullet Automotive & Diesel comes in. We’re a family-owned shop in Greeley and Fort Morgan, and our ASE Certified Technicians have True Diesel Experience with the big-bore engines and air systems that keep a Mack moving. We treat your truck like the working asset it is: get it diagnosed right, fixed once, and back on the road fast.
Why Mack Owners in Greeley and Fort Morgan Choose Bullet Automotive & Diesel
We Speak Your Language, Not Mechanic Jargon
You know your way around an engine, so we don’t talk down to you and we don’t bury the real problem in shop-talk. When you drop off your Mack, you get a straight answer in plain English about what’s wrong and what it takes to fix it.
- A clear diagnosis explained in terms that make sense
- Repairs sorted into safety must-fix now, coming soon, and down the road
- A written estimate before we touch a wrench
- Honest timelines so you can plan your jobs and your crew
No surprise line items, no ten-item list when you came in for one. Just the facts on your truck and what needs doing.
Mack Expertise Without Dealership Pricing
Mack’s MP7 and MP8 engines, mDRIVE automated transmissions, and heavy air-brake systems aren’t something every corner garage can handle. Our technicians have the diagnostic tools and the diesel background to work on them properly.
- Heavy-duty diesel diagnostic equipment for accurate fault reads
- Experience with MP-series engines and aftertreatment systems
- Fleet Maintenance Repair Specialists for your whole operation
- Independent-shop rates instead of dealership sticker shock
You get the same level of care a dealer gives without being treated like a walking wallet. Fair pricing, real expertise.
Transparency That Rebuilds Trust
If you’ve been burned by a shop that found extra work every time, we get the skepticism. We earn trust by showing you the problem, not just telling you about it.
- Comprehensive Multi-Point Vehicle Inspections with documented findings
- Written estimates and approval before any repair proceeds
- No upsell pressure on parts or service you don’t need
- Backed by our 12 month or 12,000 Mile Warranty
The goal is simple: become the shop you never have to second-guess, for one truck or a whole fleet. That’s why we say we always shoot straight.
Comprehensive Mack Repair Services in Greeley and Fort Morgan
Mack Maintenance Services
Preventive work is what keeps a Mack out of the breakdown lane, and Colorado’s swing from below freezing to 105-degree summers is hard on heavy diesels. Staying on top of scheduled vehicle maintenance is the cheapest insurance you’ll ever buy against downtime.
- Diesel oil and filter changes on MP7 and MP8 engines
- Fuel filter and water-separator service
- Coolant system flushes and inspections
- Air system and dryer maintenance
- DPF and aftertreatment servicing
- Multi-point inspections at every service interval
We build a maintenance rhythm around your miles and your workload so nothing sneaks up on you.
Mack Diagnostic and Repair Services
When something goes wrong, accurate vehicle diagnosis and repair saves you from paying for guesswork. We pull codes, verify the root cause, and fix the actual problem the first time.
- Check engine and fault-code diagnostics
- Turbocharger and EGR service
- Fuel injector and fuel system repair
- Transmission and drivetrain repair including mDRIVE
- Electrical and charging system repair
Every repair comes with a straight explanation and priority tiers so you decide what’s fixed now and what can wait for the budget.
Mack Specialty Services
Heavy trucks need heavy-truck know-how, and our diesel repair services cover the systems that separate a Mack from a light-duty pickup.
- DPF cleaning and diesel emissions repair
- Aftertreatment and DEF system diagnostics
- mDRIVE automated transmission service
- Fleet scheduling for multiple trucks
Whether you run a single day-cab or a small fleet of Macks, we keep them documented, serviced, and rolling.
Model-Specific Mack Expertise
Mack Anthem Service and Repair
The Anthem is Mack’s long-haul workhorse, and its MP-series power and mDRIVE transmission demand precise diagnostics. Common concerns include aftertreatment faults, sensor issues, and cab electrical gremlins. We keep your Anthem’s uptime high with thorough diagnostics and preventive service tuned to your route miles.
Mack Granite Service and Repair
The Granite lives in the rough world of dump, mixer, and construction duty around Adams County. That heavy vocational use punishes suspensions, brakes, and cooling systems. We handle Granite air-brake service, suspension repair, and cooling-system work so your vocational rig keeps hauling in Colorado’s harsh conditions.
Mack Pinnacle Service and Repair
The Pinnacle bridges regional and long-haul work, and owners often ask about EGR, turbo, and fuel-system performance. Loss of power and derate conditions are frequent complaints on high-mileage units. We diagnose the root cause and repair the fuel and emissions systems so your Pinnacle pulls the way it should.
Mack TerraPro Service and Repair
The TerraPro is built for refuse and severe-service applications with constant stop-and-go abuse. Brakes, driveline components, and hydraulic systems take a beating in that duty cycle. We keep TerraPro units safe and running with brake, driveline, and electrical repair designed for high-cycle work.
Mack CHU/CXU Service and Repair
Older CHU and CXU tractors still earn their keep, but age brings wiring issues, air leaks, and aging aftertreatment hardware. We troubleshoot electrical faults, chase down air leaks, and service the emissions systems so these proven rigs stay reliable and DOT-ready.
Common Issues Across Mack Models
Mack trucks are built tough, but every heavy diesel shares a set of predictable trouble spots as the miles pile up. Here’s what we see most and how we handle it.
- Aftertreatment and DPF faults: Clogged DPFs and DEF system errors trigger derates that kill your power; we clean, diagnose, and repair the emissions system to clear them properly.
- EGR and turbo problems: Sticking EGR valves and failing turbos cause loss of power and rough running; we test and repair these to restore performance.
- Air system leaks: Slow air buildup and dropping pressure point to leaks or a tired dryer; we track down and seal the leak so your brakes work every time.
- mDRIVE transmission concerns: Shift faults and clutch actuator issues on automated boxes need proper diagnostics; we service and repair mDRIVE units correctly.
- Cooling system failures: Colorado’s 105-degree summers stress radiators and water pumps; we flush, pressure-test, and repair the cooling system before it strands you.
- Electrical and sensor faults: Corroded connections and failing sensors throw confusing codes; we diagnose the real culprit instead of throwing parts at it.
The Bullet Automotive & Diesel Difference for Mack Owners
When your truck is your income, you can’t afford a shop that gambles with your time or your trust. Here’s what working with us actually looks like.
- Respects your time with efficient service and honest turnaround estimates
- Respects your wallet with written estimates and no surprise line items
- Respects your knowledge with plain-English answers, never talked down to
- Respects your business with Fleet Maintenance Repair specialists who keep every truck rolling
The result is a shop you stop second-guessing. You get your Mack back running right, you plan your week without dreading a breakdown, and you finally have a diesel team on speed dial that shoots straight every single time.
Service Areas We Serve
From our Greeley and Fort Morgan locations, we handle Mack repair and maintenance for owner-operators and fleets across the Front Range and the eastern plains.
- Greeley and Fort Morgan — our home shop in Greeley and Fort Morgan
- Commerce City — heavy-duty and fleet trucks welcome
- Henderson — convenient diesel service nearby
- Thornton — dependable repair for working trucks
- Greeley — full diesel and fleet support
- Fort Morgan — serving the eastern plains hauling routes
- Fort Lupton — trusted maintenance for local operators
Schedule Your Mack Service Today in Greeley and Fort Morgan, CO
Ready for a diesel shop that treats your Mack like the working asset it is? Bring it to the team that gives you the real story, fair pricing, and fast turnaround so you get back to earning.
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 your neighbors are saying and get directions on our reviews page, then call to book your Mack in.
Call 970-415-8018 today. We always shoot straight — and we’ll keep your Mack shooting straight down the road.