Heavy-Duty Truck Repair
Engine, electrical, air, brake and drivetrain repair for tractors and straight trucks.
Built around less downtime.
A heavy-duty truck earns money only when it is moving. When an engine derates, a starter fails or the air system loses pressure, every hour parked is an hour of lost revenue. Fellows sends a mobile mechanic to the truck so diagnosis starts where the problem is, not after a tow.
Our truck repair services cover the faults drivers and fleets report most: engine and emissions diagnostics, no-start and electrical problems, cooling and fuel system faults, brakes and air systems, and drivetrain and suspension wear. Each service page explains the symptoms, what the work involves and where mobile repair has limits.
Diagnose first
Codes, tests and inspection before parts are replaced, so you pay to fix the real fault.
Where the truck is
Roadside, truck yard, customer site or jobsite, where service is feasible and safe.
Honest limits
If a repair needs a shop or a tow, we say so early rather than after a wasted visit.
Reachable 24/7
Call or message at any hour. Breakdowns do not keep office hours.
What we are usually called for.
Tap a fault to see the service, the symptoms and what mobile repair can and cannot do.
Engine & emissions
Fault codes, derates, DPF/SCR warnings, sensors and rough running.
Starting & electrical
No-starts, batteries, starters, alternators, wiring and lights.
Brakes & air
Air leaks, compressor trouble and brake system repair.
Cooling, fuel & drivetrain
Overheating, fuel faults, clutch, driveshafts and suspension.
Keep the truck earning.
From a quick battery test to a full diagnostic visit, tell us what the truck is doing and we will tell you what can be done where it sits.
Heavy-Duty Truck Repair: full list.
Every service in this category has its own page with symptoms, what the work involves and the limits of mobile repair.
- 01Engine Diagnostics & Troubleshooting
- 02Engine Repair
- 03Oil & Filter Change
- 04Preventive Maintenance
- 05Coolant System Repair
- 06Radiator & Hose Repair
- 07Fuel System Repair
- 08Starter Replacement
- 09Alternator Replacement
- 10Battery Testing & Replacement
- 11Electrical Wiring Repair
- 12No-Start Diagnostics
- 13Air Compressor Repair
- 14Air Leak Repair
- 15Brake System Repair
- 16Belt & Hose Replacement
- 17DPF / SCR System Diagnostics
- 18Check Engine Light Diagnostics
- 19Sensor Replacement
- 20Transmission Diagnostics
- 21Clutch Repair
- 22Driveshaft & U-Joint Replacement
- 23Suspension Repair
- 24Lights & Wiring Repair
On-site repair depends on the fault, parts, vehicle condition, safety and service feasibility.
What mobile repair can and cannot do.
Honest expectations up front. If your job is on the right-hand list we will say so before anyone drives out.
Often possible on site
- Fault code reading and system testing
- Battery, starter and alternator replacement
- Air leaks, lines and fittings
- Sensors, wiring, lights and fuses
- Belts, hoses and filters
- Oil and filter service
May need a shop or tow
- Major internal engine work
- Transmission and clutch replacement
- Frame and structural repair
- Work needing a lift, press or controlled environment
Whether a repair can be completed on site depends on the fault, parts, vehicle condition, safety and service feasibility.
Four ways to avoid the next call.
Do the walk-around
Leaks, worn tires, cracked hoses and loose wiring are easiest to catch before the trip.
Do not clear codes and carry on
Codes that return are telling you something. Write them down and get them checked.
Watch the batteries in winter
Cold exposes weak batteries first. A quick test beats a no-start at 5 a.m.
Report small changes early
A new noise, a longer air build-up or a softer pedal is cheaper to fix when it is small.
From first call to a running truck.
Call or message
Tell us where the unit is.
Describe the fault
Symptoms, lights, noises, leaks.
Agree the plan
Feasibility and dispatch, discussed honestly.
Diagnose and repair
On site where it is possible and safe.
Serving the whole GTA.
Pick your community for local information and the services we offer there.
Common questions.
What truck faults can a mobile mechanic usually handle?
Many electrical, starting, air, brake, sensor and maintenance faults can be handled on site when parts are available. Major internal engine or transmission work usually needs a workshop.
Can you diagnose a check engine light or derate on site?
Yes. On-site diagnostics reads the codes and tests the related systems. Some emissions faults need specific parts or equipment, and we will explain the options.
Do I need to know what is wrong before I call?
No. Describe what the truck is doing, any warning lights, noises or leaks, and where it is. That is enough to start.
More answers on the FAQ page.
Stranded on the Road? Let's Talk.
Tell us where your truck or trailer is located and what happened. Contact Fellows to discuss mobile repair options and next steps.
(437) 601-8551Have ready: exact location, truck or trailer type, what happened or what warnings you see, whether the unit is somewhere safe, and a callback number. Timing, dispatch and on-site repair depend on location, availability, the fault, parts and safety.