Temperature Gauge Climbing
A gauge that climbs on a hill, in traffic or under load means the heat is not getting out. Stop and call before it does damage.
Checked:Fan clutchRadiatorThermostat
Stop and call
Heavy-duty cooling systems · Louisville, KY
Heavy-Duty CoolantSystem Repair.
A heavy-duty engine makes a lot of heat, and the coolant system carries it off before it does serious damage. Superior Truck & Trailer repairs fan clutches, flushes plugged radiators and fixes the rest of the cooling system on heavy-duty trucks and fleets in Louisville, KY.
- Fan ClutchOn, off or erratic
- Plugged RadiatorFlushed and flowing
- Pump & HosesPump, thermostat, hoses
How the heat gets out
Fan, Radiator And Loop.
An engine with its cooling system: coolant picking up heat in the block, the thermostat and the water pump moving it, and the radiator and the fan giving the heat to the outside air.
Malfunctioning Fan Clutch
Most heavy-duty trucks have a fan clutch that turns the cooling fan on and off. They are durable, but a fan clutch that fails is one of the leading causes of an overheating engine. A complete set of fan clutch repairs gets the truck back on the road.
Plugged Radiator
The radiator's channels carry the coolant past cool outside air to give off the engine's heat. When old fluid, rust or outside contaminants clog them, too little heat gets out and the engine overheats. The radiator gets flushed and the truck goes back on the road.
Water Pump, Thermostat And Hoses
The water pump pushes the coolant round, the thermostat decides when it goes to the radiator, and the hoses carry it between them. A leak or a failed part anywhere in the loop ends in the same place: an overheating engine.
Fan clutch checklist
Won't engage: what gets checked
- Engine temperature when it should engage
- Air or electrical signal to the clutch
- Air leaks at the clutch
- The solenoid and its wiring
- Temperature sensor readings
- Friction lining wear
Won't disengage: what gets checked
- Fan running with the engine cold
- A clutch locked up
- Air supply and the solenoid
- Fan noise and fuel use
- Bearing play at the hub
- Belt wear from the load
Erratic: what gets checked
- Engagement against temperature
- Loose wiring and connectors
- Sensor readings that jump
- Air pressure at the clutch
- The A/C pressure switch
- Codes and freeze-frame data
Radiator checklist
Radiator flow: what gets checked
- Temperature in and out
- Cold spots across the core
- Coolant condition and color
- Coolant mix and level
- Airflow through the fins
- Shrouds and seals
Plugged: what gets checked
- Rust and scale in the channels
- Old or mixed coolant
- Dirt and bugs in the fins
- Oil in the coolant
- Bent or packed fins
- Leaks at the tanks
The flush: what gets done
- Old coolant drained out
- The system flushed through
- Fins cleaned from the back
- Refilled with the right coolant
- Air bled out of the system
- Temperatures checked after
Coolant loop checklist
Water pump: what gets checked
- Coolant at the weep hole
- Bearing play and noise
- Belt and tensioner
- Flow with the engine running
- Gasket leaks
- Impeller wear
Thermostat: what gets checked
- Warm-up time
- A thermostat stuck shut
- A thermostat stuck open
- Opening temperature
- The housing and its seal
- Temperature gauge readings
Hoses and leaks: what gets checked
- Cracked, soft or swollen hoses
- Clamps tight and sealing
- The pressure cap
- Cooling system pressure test
- Drips, crust and stains
- Coolant loss with no puddle
The cooling system, part by part
Fan Clutch & FanEngaging, disengaging and erratic fans, repaired.
RadiatorPlugged channels flushed, leaks and damage repaired.
Water PumpLeaks, bearings and flow.
ThermostatStuck open or shut, and the housing.
Hoses & ClampsCracked hoses, loose clamps and the pressure cap.
CoolantThe right coolant, mixed and bled.
Related repairs and services
EGR & DPFThe EGR cooler, and coolant lost into the exhaust.Engine Repair, Rebuild & ConversionWhen overheating has already hurt the engine.HVAC System RepairCab heat and A/C, which share the cooling system.Preventive MaintenanceCoolant, hoses and belts checked on a schedule.General Diesel RepairDiesel repair across the whole truck.24/7 Mobile & Roadside AssistanceOverheated on the interstate, any hour.
What drivers notice first
Signs Of A Cooling Problem.
Where each one usually leads. Caught early, overheating is a clutch, a flush or a hose, not a cylinder head or an engine.
The Fan Never Kicks On
A fan that stays off when the engine is hot is a fan clutch that won't engage, one of the leading causes of overheating.
Checked:Fan clutchSolenoidSensor
Repair now
The Fan Roars All The Time
A fan that runs even with the engine cold is a fan clutch that won't disengage. It costs fuel and power and wears the belt.
Checked:Fan clutchAir supplyBelt
Often a repair
Steam Or A Sweet Smell
Steam or a sweet smell from under the hood is coolant escaping onto something hot: a hose, a clamp, the radiator or the water pump.
Checked:HosesRadiatorWater pump
Repair now
Coolant Keeps Going Down
Topping off again and again means it is leaking somewhere. A pressure test finds it, whether it drips on the ground or not.
Checked:Pressure testHosesEGR cooler
Diagnose soon
A Puddle Under The Front
Green, orange or pink under the front of the truck is coolant. Where it drips from points at the radiator, a hose or the water pump.
Checked:RadiatorHosesWater pump
Repair soon
Cooling work
From The Fan To The Fill.
Cooling work runs from the fan and the radiator at the front of the truck to the pump, the thermostat and the hoses on the engine.
How cooling work moves through the shop
From the first call to an engine that runs at temperature.
Tell us the truck and what it is doing. We check the cooling system, lay out the repair, do the work and get the truck back into service.
01You call
Tell us the truck and what it is doing: the gauge, the fan, the steam, the coolant going down.
02We check it
The fan clutch, the radiator and the coolant loop get checked, with a pressure test to find any leak.
03You approve it
The clutch, the flush or the pump, laid out up front. Nothing gets done until you approve it.
04You roll
The repair gets done, the system gets refilled and bled, and the temperatures get checked before the truck goes back to work.
Working trucks, real shop work
The work happens here, on the road and in the bay.
The trucks, trailers, service vehicles, roadside calls and shop work behind the services on this site. This is the kind of commercial equipment Superior works on every day in and around Louisville.
Truck repair customer reviews
What Drivers SayAbout The Shop.
Read customer feedback on Superior Truck & Trailer's repair work, communication, and service experience in Louisville.
Cooling work backed by a full truck shop
The Rest Of The Truck,Same Shop.
An overheating engine can take other parts with it. Everything else it needs is handled from the same Louisville shop.
Coolant system FAQ · Louisville, KY
Truck Cooling Questions.
Fan clutches, radiators, water pumps and overheating: the cooling questions truck owners and fleets ask most.
(502) 789-6644What does the coolant system do on a heavy-duty truck?
A heavy-duty engine makes a lot of heat that has to be carried off to avoid serious damage. The coolant absorbs the heat in the engine, and the radiator gives it off to the outside air, which keeps the engine temperature under control.
What are the most common causes of an overheating truck?
Two of the most common are a malfunctioning fan clutch and a plugged radiator. A stuck thermostat, a failing water pump, a leaking hose and low coolant cause it too.
What does a fan clutch do?
Most heavy-duty trucks have a fan clutch that controls the cooling fan, turning it on when the engine needs more air through the radiator and off when it does not.
What are the symptoms of a bad fan clutch?
A cooling fan that does not engage, one that does not disengage, or one that engages erratically and unpredictably. A fan that will not engage is one of the leading causes of an overheating engine.
Can a fan clutch be repaired?
Yes. Superior Truck & Trailer offers a complete set of fan clutch repairs, from the clutch itself to the air or electrical controls that tell it when to engage.
What causes a radiator to plug up?
The radiator's channels carry the coolant past cool outside air. Old fluid, rust and outside contaminants can clog them, and then too little heat gets given off and the engine overheats.
What is a radiator flush?
The old coolant gets drained, the system gets flushed through to clear the channels, and it gets refilled with fresh coolant and bled of air. A plugged radiator gets flushed so the truck can get back on the road.
How do I know if my water pump is going bad?
Common signs are coolant weeping from the pump, a noisy or wobbling pump pulley, and a temperature that climbs because the coolant is not moving the way it should.
What happens if the thermostat sticks?
A thermostat stuck shut keeps the coolant from reaching the radiator, and the engine overheats. One stuck open lets the engine run too cool, which costs fuel and cab heat.
Why does my truck keep losing coolant?
It is leaking somewhere: a hose, a clamp, the radiator, the water pump or the pressure cap. If there is no puddle, it can be leaking inside, such as through an EGR cooler. A pressure test finds it.
Is it safe to keep driving an overheating truck?
No. Overheating can warp a cylinder head, blow a head gasket or damage the engine. Pull over safely, shut it down and call. Superior Truck & Trailer runs 24/7 roadside assistance for exactly that.
Where can I get truck coolant system repair near Louisville, KY?
Superior Truck & Trailer repairs heavy-duty truck cooling systems at 3816 Bishop Lane in Louisville, KY, for trucks from Louisville and the surrounding Kentucky and Southern Indiana counties. Call (502) 789-6644 with the truck and what it is doing.
Running hot or losing coolant?
Get The Cooling Sorted.
Call Superior Truck & Trailer in Louisville, KY with the truck and what it is doing. We'll find why it is running hot and fix it before it costs you an engine.
(502) 789-6644
3816 Bishop Lane #1, Louisville, KY 40218