Engine Diagnostics and Repair
Fault code diagnosis and in frame repair on Cummins, Detroit, Paccar, Caterpillar and other major diesel platforms.
Learn moreIn shop, mobile diagnosis
AC and Heating Repair
Cab climate is a safety and retention issue, not a comfort one. A driver who cannot cool the cab in a Baltimore July is a driver who is fatigued and looking at other jobs.
AC and Heating in Baltimore, MD
Air conditioning complaints are almost never just low refrigerant. Refrigerant does not get consumed, so a system that is low has a leak, and adding gas without finding the leak means you are back in six weeks having lost the gas and the money. We evacuate, pressure test, find the leak with dye or an electronic detector, repair it, then recharge to the manufacturer weight. Heating faults get the same treatment: a heater that blows cold is usually a coolant flow, blend door or blower problem, and each of those is a different repair.
Equipment and capability
We use recovery and recharge machines that measure by weight, along with electronic leak detection and UV dye. Heavy truck systems are handled alongside APU and bunk climate systems. Most AC work is done in the shop where the system can be evacuated and held under vacuum properly, though diagnosis and simple repairs happen mobile.
In shop, mobile diagnosis
Covering Baltimore City and 29 surrounding communities, out to roughly 30 miles from the shop on Ponca Street.
See the areas we coverWhat ac and heating covers
The full scope of the work, so there is no ambiguity about what is and is not included when you approve a job.
- Full AC performance test with manifold gauges and vent temperature measurement
- Leak detection using electronic detectors and UV dye
- Refrigerant recovery, evacuation and recharge to manufacturer specified weight
- Compressor, clutch, condenser, evaporator and receiver drier replacement
- Expansion valve and orifice tube service
- AC hose and line repair or replacement, including crimped fittings
- Blower motor, resistor and speed control fault diagnosis
- Heater core replacement and coolant flow diagnosis
- Blend door actuator and cab control head faults
- Cab air filter replacement
- APU and bunk climate system faults where fitted
- Cooling fan clutch and engine cooling checks where they affect AC performance
When you need this service
If you recognise any of these, it is worth a call before it becomes a roadside call.
AC blows warm or only cools while the truck is moving
AC works for a while then stops, and returns after the truck has been shut off
Compressor clutch does not engage, or cycles rapidly
Noise from the compressor when the AC is switched on
Heater blows cold air, or only warms up on a long run
Blower works on some speeds but not others
Windshield fogs and will not clear
Sweet smell or damp carpet in the cab, which usually means a heater core leak
How we approach it
The sequence matters as much as the repair. Working through it in this order is what stops you paying for parts the fault never pointed at.
- 1
Measure the performance
Manifold gauges on high and low side, plus vent temperature and ambient. The pressure readings tell us whether we are looking at a charge problem, a blockage or a compressor fault.
- 2
Find the leak before adding gas
A system that is low is leaking. We pressure test, use dye or an electronic detector, and locate the leak rather than topping it up and sending you away.
- 3
Repair the cause
Hoses, seals, condensers, compressors or the evaporator, whichever failed. If the compressor came apart internally, the system gets flushed and the drier replaced so debris does not kill the new one.
- 4
Evacuate and recharge by weight
The system is evacuated to pull out moisture, held under vacuum to confirm it holds, then charged to the manufacturer specified weight rather than to a gauge reading.
- 5
Verify at the vent
Final vent temperature checked against ambient at idle and at high idle, so you know the system works in the conditions it will actually face.
Related services
Faults rarely sit in one system. These are the ones that most often come up alongside this work.
Electrical System Repairs
Wiring faults, ECM and ECU diagnostics, lighting, charging systems and sensor replacement on tractors and trailers.
Learn morePreventive Maintenance
Scheduled PM services, oil and filter changes, fluid checks and DOT pre-trip inspections, on your yard or ours.
Learn moreFurther reading on ac and heating
Truck AC Blowing Warm: What the Gauges Tell You Before You Add Any Gas
Refrigerant is not consumed. A system that is low is leaking, and topping it up without finding the leak means paying for the same gas twice.
Read the articleEngine and Emissions
Truck AC Blowing Warm: What the Gauges Tell You Before You Add Any Gas
Refrigerant is not consumed. A system that is low is leaking, and topping it up without finding the leak means paying for the same gas twice.
4 min read
Book ac and heating
Send the unit details and the symptom and dispatch will come back to you. If the truck is off the road right now, call instead.
Faster by phone
A form is fine for scheduling. For a truck that is stopped, a call gets a unit moving while you are still describing the problem.
(443) 630-6669- Call out fee and labour rate quoted before we roll
- Work stops and you get a call if the job grows
- Itemised invoice with parts, labour and measurements
AC and Heating questions
Drawn from the questions we get asked most about this specific service.
We can, but we will tell you plainly that it is a temporary fix. Refrigerant does not get used up. If the system is low it is leaking, and the gas you pay for will be gone again. Finding the leak is usually a small job on top of the recharge.
That normally points at airflow across the condenser, which means a fan clutch problem, a blocked condenser, or a system charge issue that only shows when airflow drops. All three are testable.
It varies by chassis and whether a bunk system is fitted. We charge to the specified weight for your unit, which is on the underhood label, rather than filling to a gauge pressure.
It could be, but blend door actuators, air in the cooling system and a stuck thermostat all produce the same complaint. We check coolant flow through the core before condemning it, since replacing a heater core is a dash out job on many trucks.
Yes, on the common APU and bunk cooling systems. Tell dispatch the make when you call so we bring the right parts.
A leak repair and recharge is usually the same day. A compressor or condenser replacement is typically a day. An evaporator or heater core can be two days on trucks where the dash has to come out.