Pick-up
Coordinate free equipment or component pick-up when applicable.
24-Hour Rush Repair
Independent Cummins service · Fontana, CA
Cummins Engine Repair in Fontana
Cummins Engine Repair in Fontana is core work at Top Notch Equipment Repair in Fontana. Expect a documented teardown, honest measurements, in-house machining and a tested result — with free quotes and a rush line that answers 24 hours a day, 365 days a year.
Independent Cummins service · Fontana, CA
Cummins work we do every week
Equipment comes in dead and leaves working: the failure is documented, the repair is quoted from real measurements, and the machining, welding, grinding and rebuilding all happen in-house. Free pick-up and delivery keep the logistics off your crew, and rush work runs around the clock, every day of the year.
Brands we serviceCummins
Cummins Engine Repair in Fontana · Fontana, CARebuild depth behind every Cummins job
An engine shop earns its name on the hard jobs: the in-frame done with the block measured, the derate traced past the sensor it blamed. That work happens here with machining and gear manufacturing in the same building — documented with photos and video, quoted in writing before it starts. Free pick-up and delivery when applicable; Monday–Friday 6 AM–5 PM, and the 24-hour rush line runs every day of the year.
- In-frame rebuilds — ISB, ISC, ISL, ISX, X15
- Aftertreatment: DPF, SCR, DEF and derate faults
- Injectors, turbos and high-pressure fuel systems
- Cylinder head and head gasket work
- Cummins power in equipment — QSB, QSC, QSL
Our 8-step repair process
A clear path from the first call to a tested component or machine returned to work.
Inspection
Disassemble and evaluate the complete failure.
Photos & video
Document condition and findings for a clear repair conversation.
Repair quote
Define the recommended work and quote before proceeding.
Approval
Confirm scope, urgency and the practical path forward.
Manufacturing
Machine, weld, rebuild or reverse engineer required components.
Testing
Verify operation and workmanship before release.
Shipment
Return the completed component or equipment to service.
Frequently asked questions
Are you a Cummins dealer or distributor?
No — we are an independent repair shop that specializes in Cummins diesel engines among the brands we service. No affiliation is implied.
My truck keeps derating — can you find the real cause?
Yes. Derates are symptoms: we diagnose the aftertreatment and sensor chain end to end and show you the readings, instead of replacing the part the code names.
Do you rebuild Cummins engines or only repair them?
Both — from top-end and in-frame rebuilds to complete out-of-frame overhauls, with machining done in-house.
Related services
Emergency breakdown? Call the 24-hour rush line.
(949) 400-2937Schedule service or open a repair order
Request a service call.
Tell us the make, model, symptoms, where the machine sits and how urgent it is. Your details open as a text to the shop, ready for you to review before you send.