Cummins Truck Repair & Maintenance in Denver, CO and Kalispell, MT

Is your Cummins engine showing signs of trouble? Iron Buffalo provides expert diagnostics and repair for ISX, X15, and other Cummins engines—keeping your truck running strong and reliable.

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Colorado

Montana

Cummins Repair & Maintenance in Denver, CO, and Kalispell, MT

Cummins engines are known for power and longevity—but they demand specialized service to stay road-ready. At Iron Buffalo, we provide complete Cummins repair in Denver, CO and Kalispell, MT for fleet trucks, heavy-duty equipment, and vocational vehicles. Whether you're dealing with derate conditions, EGR faults, or fuel injection problems, we’ll restore full engine functionality with precision.

Full-Service Cummins Engine Repairs

We provide expert support across Cummins-powered heavy-duty trucks and machinery. Our repair services include:

ISX15, X15, and earlier series diagnostics
Overhead adjustment and valve train inspections
Turbocharger repair and actuator calibration
EGR valve and cooler replacement
Fuel injector testing and replacement
DPF, SCR, and DEF system diagnostics
Engine derate resolution and ECM reprogramming
Aftertreatment system cleaning and regeneration
Fault code analysis and sensor replacement

All repairs are backed by OEM-grade diagnostics and built for long-term reliability.

Benefits of Cummins Engines

Cummins diesel engines are the gold standard in performance and durability. With strong torque, extended maintenance intervals, and proven fuel efficiency, Cummins powertrains are the choice of top fleets across North America.

From the ISX and X15 to the B and L Series, Cummins engines are engineered for versatility and emissions compliance. Their integration with modern aftertreatment systems and onboard diagnostics makes early issue detection easier and repairs more targeted.

Need Cummins Engine Repair Service?

Need expert Cummins engine service? Call Iron Buffalo at 303-623-7049 (Denver) or 406-890-7001 (Kalispell). We deliver fast, professional Cummins diagnostics and repairs to keep your truck performing.

FAQs

What Areas Do You Serve?

We offer 24/7 mobile repairs and roadside assistance in the following areas:

Colorado: Boulder, CO; Aurora, CO; Centennial, CO; Fort Collins, CO; Greeley, CO; Georgetown, CO; Brighton, CO; Castle Rock, CO; Colorado Springs, CO; and Longmont, CO.

Montana: Whitefish, MT; Bigfork, MT; Somers, MT; Polebridge, MT; Thompson Falls, MT; Polson, MT; Rollins, MT; Libby, MT; and Eureka, MT.

What Cummins Engines Do You Work On?

We service ISX15, X15, ISL9, ISC, ISB6.7, and other models used in heavy-duty, mid-range, and vocational applications.

Can You Diagnose and Clear Fault Codes?

Yes. We use Cummins Insite software to access, diagnose, and clear fault codes. We also reset derate conditions and perform forced regens.

How Can I Get in Touch?

If you're ready to schedule diesel repairs, call Iron Buffalo today at 303-623-7049 (Denver) or 406-890-7001 (Kalispell).

Manufacturers

Customer testimonials

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"I highly recommend this shop. I had luke a technician there do some work on my truck after a ford dealership took 6 days and failed to acknowledge my warranty on 3 leaking oil spots on my truck.Once the dealership screwed me over I took my truck here. Luke was very impressive, fast and communicative. He provided me photos. He kept me updated on everything he did. I still have a warranty through ford but apparently it’s useless. I don’t think I’ll ever go back to them considering how they treated me. Luke is a solid technician who is very skilled. I can’t recommend him enough. Thank you."

Tristen

"Our truck broke down just as we were getting into Denver. It was a major repair and they accomplished it quickly and we were back in our truck. Everyone there was very professional and nice to work with. The unhappy news of a major repair was actually a good experience. Definitely recommend Iron Buffalo."

Kelly

"I’m glad I went to this shop. I was so worried it would be another back door mechanic wanting to swindle me. It was anything but. Shannon was super kind and went way out of his way getting me in right away. And Steve was a professional from start to finish in assisting with the work being done. I’m really appreciative and would 100% use this shop again."

Kristin

"Steven Riddle is the best service writer if ever dealt with. He is very knowledgeable, I called with starting issues. With in 1hour try had my truck towed in. That day they had it diagnosed then next day they found the parts. Great job, I will be using in the future. Thanks a lot."

Mike

"Kanisha was great, I had been trying to get my small hydraulic cylinder repaired for quite some time and she was the first person that said "YES" she was honest about needing to look first. She was willing to listen and explained the process. When I came in she was polite and professional. She communicated like she said she would and got it taken car of! I'll recommend Kanisha and Iron Buffalo!"

Lance

"I'm very happy with the service I received from Iron Buffalo Holdings I highly recommend this shop. I got an Inspection & a DYNO done on my Semi Truck. Canesha was prompt and courteous."

Miko

"Had a break down with the ol’ Pete they picked up and were available l. They aren’t the cheapest but heck you get what you pay for. If you want your rig or RV fixed so you can head one down the road these guys are nice and they can almost always get done in a day if you need it."

Bryan

Light, Medium & Heavy-Duty Truck Repair Services in Denver, CO & Kalispell, MT

Trusted Diesel Repair & Fleet Services - Keeping You on the Road & Job Site

Commerce City, CO

5590 E 55th St, Commerce, City, CO

303-623-7049

Kalispel, MT

104 Rocky Cliff Lane, Unit 1, Kalispell, MT

406-890-7001