Mack Truck Repair & Service in San Bernardino, CA

Mack trucks are used for hauling, construction, refuse, delivery, vocational work, and other demanding commercial applications. Because Mack trucks can be built with different engines, transmissions, axles, emissions systems, and equipment, maintenance and repair needs vary by model, year, configuration, and use.

Direct Truck & Auto Repair provides Mack truck maintenance, diagnostics, and repair in San Bernardino, CA. Whether your truck has a warning light, loss of power, brake concern, shifting problem, emissions issue, fluid leak, or maintenance need, we start with inspection and testing before recommending repairs.

Call 909-746-0188 or schedule an appointment online if your Mack truck needs service or repair.

Mack Truck Models We Service

Mack has produced a range of medium-duty, heavy-duty, and vocational trucks. Depending on model year and configuration, Mack trucks that may come in for service include:

• Mack Anthem
• Mack Pinnacle
• Mack Granite
• Mack Granite MHD
• Mack LR
• Mack TerraPro
• Mack MD Series
• Other Mack commercial trucks

Specifications can vary within the same model family. Engine, transmission, GVWR, axle configuration, emissions equipment, and vocational upfits should all be considered when planning service.

Common Mack Truck Maintenance & Repair Needs

Commercial trucks often operate under demanding conditions. High mileage, extended idling, frequent stops, heavy loads, construction work, and highway operation can all affect maintenance needs and component wear.

Depending on the truck and its condition, Mack service may involve:

• Diesel engine diagnostics and repair
• Check engine and warning-light diagnostics
• Preventive maintenance
• Brake inspection and repair
• Cooling-system concerns
• Transmission diagnostics and repair
• Electrical system diagnostics
• Steering and suspension inspection
• Wheel alignment
• DPF and exhaust aftertreatment concerns
• Fluid leak diagnosis
• Fleet maintenance

The correct service depends on the specific truck, engine, mileage, engine hours, duty cycle, operating conditions, and maintenance history.

Mack Diesel Engine Service

Mack trucks have been offered with different diesel engine configurations depending on the model and year. Fuel systems, turbochargers, cooling systems, electronic controls, and emissions equipment can also vary.

Possible signs of a diesel engine concern may include:

• Hard starting
• Loss of power
• Rough running
• Unusual exhaust smoke
• Fluid leaks
• Higher-than-normal engine temperature
• Check engine or other warning lights

These symptoms do not identify one specific failed component. Fuel delivery, air intake, turbocharger operation, sensors, wiring, cooling-system components, emissions equipment, or internal engine conditions may be involved.

For related service information, visit our diesel service and engine repair pages.

Mack Check Engine Lights & Diagnostics

Modern commercial trucks use electronic controls to monitor engine, transmission, emissions, and electrical systems.

A diagnostic trouble code can help identify a system or operating condition that needs further testing. It does not automatically confirm which component needs replacement.

Depending on the concern, diagnosis may include:

• Reading stored fault codes
• Reviewing operating data
• Testing electrical circuits
• Inspecting sensors and connectors
• Checking related mechanical systems
• Confirming the reported symptom

Learn more about our computer diagnostic services.

Mack DPF & Emissions System Service

Many diesel Mack trucks use exhaust aftertreatment systems designed to reduce emissions. Depending on model and year, these systems may include a diesel particulate filter and other emissions components.

Possible signs of an aftertreatment concern may include:

• DPF or emissions warning lights
• Regeneration concerns
• Reduced engine power
• Repeated fault codes
• Changes in exhaust-system operation

A DPF warning does not automatically mean the filter needs cleaning or replacement. Engine performance, sensors, exhaust temperatures, operating conditions, or other emissions components may contribute to the problem.

Testing helps determine the cause before service is recommended.

Learn more about our DPF service.

Mack Transmission Repair & Diagnostics

Mack trucks may use different transmission designs depending on model, year, engine, and application. Service and diagnostic procedures should match the specific transmission installed in the truck.

Possible transmission or drivetrain concerns may include:

• Delayed engagement
• Harsh or unusual shifting
• Difficulty selecting a gear
• Warning lights or fault messages
• Fluid leaks
• Unusual noises
• Vibration or changes in drivability

These symptoms do not automatically mean the internal transmission has failed. Clutch components on applicable trucks, sensors, wiring, electronic controls, engine performance, or other drivetrain components may also affect operation.

Learn more about our transmission repair services.

Mack Truck Brake Service

Mack truck brake systems vary by vehicle and configuration. Brake wear can also be affected by truck weight, load, route, terrain, traffic, and operating conditions.

Possible reasons to have the braking system inspected include:

• Changes in braking performance
• Unusual brake noises
• Pulling during braking
• Brake or ABS warning lights
• Air-system concerns on trucks equipped with air brakes
• Visible wear, damage, or leaks

Several brake and chassis conditions can create similar symptoms. Inspection is needed before deciding which components require repair.

Mack Cooling System Repair

Commercial diesel engines rely on the cooling system to manage engine temperature, especially while hauling, idling, climbing grades, or working under load.

Possible cooling-system concerns may include:

• Coolant leaks
• Higher-than-normal engine temperature
• Repeated coolant loss
• Cooling fan concerns
• Damaged hoses or connections
• Temperature warning lights or messages

An overheating truck should be inspected rather than assuming a particular component has failed. Radiators, hoses, thermostats, pumps, fans, sensors, leaks, or other conditions may be involved.

Mack Steering, Suspension & Wheel Alignment

Pulling, uneven tire wear, steering play, or changes in handling may point to a steering, suspension, tire, or alignment concern.

Heavy loads, road conditions, mileage, worn components, and previous repairs can all affect alignment and handling.

Learn more about our wheel alignment services.

Preventive Maintenance for Mack Trucks

Regular preventive maintenance can help truck owners and fleet managers monitor vehicle condition and identify some developing concerns before they become more disruptive.

Depending on the truck, preventive maintenance may include checking or servicing:

• Engine oil and filters
• Fuel and air filters
• Fluid levels and condition
• Brake-system components
• Tires and wheels
• Steering and suspension components
• Cooling-system components
• Belts and hoses
• Batteries and charging systems
• Lighting and electrical systems
• Transmission and drivetrain components
• Applicable emissions-system components

Maintenance intervals vary by model, engine, mileage, engine hours, duty cycle, and operating conditions. Manufacturer recommendations for the specific truck should be considered when planning service.

Learn more about our preventive maintenance services.

Medium-Duty Mack Truck Repair

Some Mack trucks are designed for medium-duty commercial applications such as local delivery, service bodies, towing, and other vocational work.

The exact truck class depends on the manufacturer's GVWR for the specific vehicle. Model name alone should not be used to determine truck class.

For related service information, visit our medium-duty truck repair page.

Heavy-Duty Mack Truck Repair

Mack heavy-duty and vocational trucks may operate under demanding conditions that include heavy loads, long highway routes, extended idling, frequent stops, and job-site use.

Those conditions can affect maintenance requirements for the engine, brakes, drivetrain, cooling system, tires, suspension, and emissions equipment.

Learn more about our heavy-duty truck repair services.

Mack Fleet Service

Businesses operating Mack trucks may need to coordinate maintenance around routes, deliveries, construction schedules, and vehicle availability.

A planned maintenance approach can help fleet managers monitor vehicle condition and make routine service easier to schedule. Preventive maintenance cannot eliminate every breakdown, but it can help identify some developing concerns earlier.

For businesses managing multiple commercial vehicles, visit our fleet service page.

Mobile Service for Mack Trucks

Moving a commercial truck to the shop is not always practical. Depending on the vehicle, location, and work required, some inspections, maintenance, diagnostics, or repairs may be suitable for mobile service.

More involved work may require shop equipment or additional testing, so availability depends on the specific situation.

Learn more about our mobile truck service.

California Commercial Truck Requirements

Some Mack trucks operated commercially in California may be subject to inspection or emissions requirements based on vehicle weight, configuration, fuel type, and use.

For applicable vehicles, visit our BIT Program service and CARB Clean Truck Check pages.

Requirements can change and may not apply to every truck. Owners and fleet operators should confirm the current rules that apply to their specific vehicles and operation.

Mack Truck Repair FAQs

How often should a Mack truck be serviced?

There is no single maintenance interval for every Mack truck. Service needs vary by model, engine, mileage, engine hours, duty cycle, operating conditions, and maintenance history.

Does a Mack fault code tell you which part needs replacement?

No. A fault code identifies a condition or system that requires further testing. It does not automatically confirm which component has failed.

Why is my Mack truck losing power?

Loss of power may be related to fuel delivery, air intake, turbocharger operation, emissions equipment, sensors, engine controls, transmission concerns, or other mechanical and electrical problems. Diagnostic testing is needed to determine the cause.

Why does my Mack truck have a DPF warning?

A DPF warning may be related to soot loading, operating conditions, sensors, engine performance, exhaust temperatures, or other aftertreatment-system concerns. Testing is needed before recommending cleaning or replacement.

Why is my Mack truck shifting differently?

Changes in shifting may involve the transmission, clutch components on applicable trucks, electronic controls, sensors, wiring, engine performance, or other drivetrain systems. Diagnosis helps determine where the problem is coming from.

Can you service Mack fleet trucks?

Direct Truck & Auto Repair provides maintenance and repair for applicable Mack trucks used in commercial fleets. Service planning depends on the vehicles, their condition, and how they are operated.

Can Mack truck repairs be performed on-site?

Some inspections, maintenance, diagnostics, and repairs may be suitable for mobile service. More involved work may require the truck to come to the shop. Availability depends on the vehicle, location, and work required.

Can you service older Mack trucks?

Service availability depends on the model, year, configuration, condition, repair needed, and parts availability. Older Mack trucks should be evaluated individually.

How long does Mack truck repair take?

Repair time depends on the truck, symptoms, diagnostic testing, repairs required, and parts availability. After the vehicle is inspected, the shop can provide a better idea of the work involved.

Mack Truck Repair in San Bernardino and the Surrounding Area

Direct Truck & Auto Repair has served the San Bernardino area since 1996 and provides maintenance, diagnostics, and repair for Mack trucks and other commercial vehicles.

You can also view our vehicle makes we service page or learn more about the area we serve on our San Bernardino County page.

If your Mack truck has a warning light, loss of power, emissions concern, brake problem, fluid leak, shifting issue, steering concern, or maintenance need, we can inspect the truck, explain what we find, and discuss the appropriate next step.

Need Mack truck repair in San Bernardino, CA? Call 909-746-0188 or schedule an appointment online with Direct Truck & Auto Repair.