Fleet maintenance
Preventive maintenance and scheduled service for medium and heavy truck fleets. Keep your vehicles ready for the work ahead.
Medium & heavy truck specialists
Keep your
wheels
turning.
Medium and heavy truck service built around your business. Fleet maintenance, diagnostics, major overhauls and mobile service from experienced technicians with ASE certifications.
How we diagnose your truck ↗Isuzu truck specialists · Shop & mobile service · Upper Black Eddy, PA
Built around working trucks.Inside the Brennan Motorworks shop
✓ Fleet maintenance
✓ Medium & heavy trucks
✓ Mobile service available
One of our specialties
Isuzu trucks.
Experience that counts.
Our factory-trained technicians specialize in Isuzu truck service and use genuine Isuzu parts. Across our technicians, we bring over 40 years of combined experience to the work we do.
Talk to us about your Isuzu ↗Medium & heavy truck service
Keep your fleet working.
Experienced technicians with ASE certifications. Maintenance, diagnostics and repair for the trucks your business depends on.
Truck diagnostics
Find the cause of performance issues with diagnostics for medium and heavy trucks. Talk to the shop about symptoms and service needs.
Major overhauls
Major overhaul and rebuild work for working trucks, with a focus on dependable operation and getting you back on the road.
Engine & drivetrain repair
Repair services for truck engines, transmissions and drivetrain components. Discuss your vehicle and repair needs with the shop.
Mobile truck service
Service that comes to your truck. Call to discuss the location, the work needed and mobile service availability.
Batteries & starting issues
Battery service and support for truck starting problems. Contact the shop to arrange service and confirm availability.
Our diagnostic process
Answers first.
Repairs with purpose.
Your truck earns its keep on the road. Our process is built to find the cause of a problem and make an informed repair, from the first phone call to the final checks.
We diagnose the issue. We don’t just throw parts at your truck.
Professional service means listening carefully, testing methodically and putting experience to work. Our experienced technicians hold ASE certifications, and our Isuzu specialists have factory training.
Listen to the driver
Good diagnostics start with good information. We take accurate notes on what the truck is doing, when the problem happens, any warning lights and recent repair history. The driver’s observations help us focus the investigation.
Get the truck the right help
If you need a tow or a mobile service call, we help coordinate the next step promptly. Tell us where the truck is and what is happening so we can discuss the right way to get service underway.
Read the codes. Look at the whole picture.
When warning lights are present, we check for fault codes and review the information they provide. A code is a starting point for testing—not an automatic instruction to replace a part. We also investigate problems that do not trigger a warning light.
Test to find the cause
We follow the appropriate diagnostic procedures and use targeted inspections, measurements and tests to narrow down the fault. Our goal is to identify why the problem is happening before recommending a repair.
Explain the findings. Make the repair.
We explain what we found and the work needed to address it. Then we focus on the repair that solves the diagnosed issue, helping avoid unnecessary parts replacement and wasted downtime.
Check the result
After the repair, we perform the appropriate checks to confirm the diagnosed issue has been addressed. Getting your truck back to work efficiently starts with doing the diagnostic work properly.
Tell us what your truck is doing.
Have the year, make, model, warning lights and symptoms ready when you call. We’ll help you take the next step.
Inside Brennan Motorworks
Working trucks.
Hands-on experience.
A look around the shop, from fleet trucks and heavy tractors to engine overhaul work. Tap any photo to take a closer look.
Commercial trucks
Medium duty.
Heavy duty.
Ready for the job.
From individual owner-operators to working fleets, Brennan Motorworks provides service for medium and heavy trucks.
Used truck sales
Looking for your next truck?
We also offer used truck sales. Contact the shop to ask about current availability and discuss what your business needs.
Ask about used trucks ↗Call (908) 878-7127 for truck sales, shop appointments or mobile service.
Parts for sale
Find your next part.
Browse current parts listings on Facebook Marketplace. Open a listing for photos, pricing and availability, or call the shop with a parts question.
Ask about a part · (908) 878-7127 ↗Check fitment before you buy.
Have your VIN, year, model and engine details ready when you ask the shop about a part.
Parts · Facebook Marketplace
Current Marketplace listings
See what the shop has listed for sale, then open an item to view its details and contact the seller on Facebook.
Browse parts on Facebook MarketplaceOpens Facebook Marketplace in a new tab. Facebook sign-in may be required.
Google reviews
From the people
behind the wheel.
“Very helpful and knowledgeable. Great team!”
“Needless to say, he was extremely knowledgeable and fair in pricing.”
Worked with Brennan Motorworks?
Share your experience with the shop on Google.
Selected Google review excerpts. Rating and review count checked October 26, 2026; they may change.
About Brennan Motorworks
Integrity and Grit
for the toughest rebuilds
Our experienced technicians hold ASE certifications and provide service for medium and heavy trucks, including fleet maintenance, diagnostics, repairs and major overhauls.
Bring your truck to the shop or ask about mobile service. We also offer used truck sales to help keep your business moving.
Contact the shop ↗Get in touch
Let’s get your truck sorted.
Call the shop(908) 878-7127
Shop hours
| Monday–Friday | 7:30 AM–6:00 PM |
|---|---|
| Saturday | 8:00 AM–3:00 PM |
| Sunday | Closed |
Listed hours. Please call before visiting to confirm availability, appointments and holiday hours.