Diesel & Fleet Repair — Done Right, Fast.

Kenworth • Peterbilt • International • PACCAR MX • Cummins • Eaton • Cat equipment. We keep your rigs working and your business moving.

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  • Heavy-Duty Diesel Specialists
  • Fleet Preventive Maintenance
  • Diagnostics • A/C • Aftertreatment
  • Mobile Service Available
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Services

Engine & Diagnostics

Cummins, PACCAR, Detroit, International, and more. Advanced diagnostics, sensor/ECM issues, and drivability.

Aftertreatment

DPF cleaning & regen, SCR/DEF troubleshooting, derate resolution, and emission system maintenance.

PM & Inspections

Oil & filters, DOT inspections, multi-point checks, and fleet service intervals tailored to utilization.

Brakes & Driveline

Air systems, hubs & bearings, u-joints, clutches, transmissions (Eaton), and differential service.

A/C & Electrical

Compressor & evaporator service, wiring faults, battery/charging systems, and lighting repairs.

Equipment

Skid steers, excavators (e.g., Cat 308CR), hydraulics, thumb attachments, and job-site repair.

Fleet Programs

We partner with fleet managers to reduce downtime and extend asset life. Custom PM schedules, service records, and priority turnaround.

  • Consolidated billing & approvals
  • Pickup & delivery options
  • On-site/mobile maintenance
  • Service history & recommendations

Get a Fleet Quote

Send us your unit list and targets. We’ll build a maintenance plan that fits.

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Book Online

Use our Shopmonkey portal for the fastest quote & appointment scheduling.

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About Us

Pioneer Garage and Specialist LLC is a diesel-first shop focused on commercial uptime. Our team brings deep experience across Kenworth, Peterbilt, International, PACCAR MX, Cummins X15/PX9, and more.

Hours: Mon–Fri 8:00a–6:00p (Sat by appt.)

Location: 13540 FM 1937, San Antonio, TX 78221

Contact

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FAQ

Do you offer mobile service?

Yes, mobile/onsite service is available for fleets and equipment. Call for availability.

What trucks and engines do you service?

Kenworth, Peterbilt, International, Freightliner, and more — including PACCAR MX, Cummins, Detroit, Navistar.

Do you handle DPF/DEF/aftertreatment issues?

Absolutely — diagnostics, forced regens, component replacements, and maintenance.