Cummins Diesel Repair in Austin, TX
The engine people buy the truck for. We keep 5.9L and 6.7L Cummins running right — in pickups and in the medium-duty trucks that earn their keep.
Cummins service at an independent Austin shop
A Cummins will run a long time, which is exactly why the ones we see are usually working hard with real miles on them. We diagnose the fuel system, air path, and emissions as a system, because on a high-mileage Cummins the fault is often downstream of what actually broke.
Cummins platforms we service
- 5.9L 12v & 24v (1989–2007) — Lift pumps, VP44 and injection-pump issues, and the "killer dowel pin" on early 12v engines.
- 6.7L (2007.5–present) — Turbo actuators, EGR and DPF loading, CP3 and CP4 fuel systems, and injector wear.
- Medium-duty Cummins — ISB and B-series engines in box trucks, service trucks, and commercial chassis.
- Cummins in equipment — Off-road and industrial equipment running B-series power.
What we see fail on Cummins
- Lift pump and low fuel pressure — Starves the injection pump and takes expensive parts with it — worth testing before it does.
- Turbo actuator and VGT sticking — Lost power, boost codes, and a turbo that won't hold commanded position.
- EGR and DPF loading — Short-route trucks that never complete a regen end up derated and down on power.
- Injector wear and return imbalance — Rough idle, white smoke, and hard starts — confirmed with return-flow testing.
- Fuel-system contamination — When a pump goes metallic, half-measures come back. We scope the whole system.
Cummins work we handle
- Diagnostics with live data on fuel, air, and emissions systems
- Lift pump, injection pump, and injector service
- Turbocharger and VGT actuator repair or replacement
- EGR service, DPF cleaning, and regeneration faults
- Air brake and chassis work on medium-duty Cummins trucks
- Preventive maintenance and oil service on a schedule that fits how you run
Modern Diesel is an independent, Christian, veteran-owned shop — we service Cummins engines but are not a dealer or affiliated with the manufacturer. Warranty coverage on our work is set with your service advisor at the time of service.
Related services
Other diesel platforms we service
Power Stroke · Duramax · Mercedes-Benz diesel · Detroit Diesel
Bring it to the shop
We work on Cummins at our shop at 2900 N FM 973, Austin, TX 78725, serving the Greater Austin Area (Travis, Bastrop, Williamson, Hays) — Austin, Del Valle, Manor, Elgin, Pflugerville, Round Rock, and the surrounding counties. Call 512-717-2777 and tell us what it's doing, or send us the details and we'll get back to you.
Common questions
Do you service both Ram pickups and medium-duty Cummins trucks?
Yes. The same B-series family shows up in Ram 2500 and 3500 pickups and in medium-duty box and service trucks, and we work on both — including the air brakes, chassis, and DOT inspections that the commercial trucks need.
My Cummins keeps regenerating and losing power. What causes that?
Constant regeneration usually means the DPF is loading faster than it can burn off — often from short routes, but it can also be an injector, turbo, EGR, or sensor problem pushing extra soot. We diagnose the cause instead of just cleaning the filter and handing it back.
Should I replace my lift pump before it fails?
On the platforms where a failing lift pump can take the injection pump with it, replacing a weak one is cheap insurance. We test fuel pressure and tell you honestly where yours stands rather than selling you a pump you do not need yet.
Ready when you are.
Drop by the shop at 2900 N FM 973, Austin, TX 78725 or call and we’ll get you scheduled.