Semi-Truck Coolant Leak Repair in Dallas, TX

📅 8/15/2026  ·  📁 Cooling System Repair

Losing Coolant? Puddle Under the Truck? Find the Leak Before It Becomes an Overheating Problem

Constantly topping off the reservoir? Low-coolant warning that keeps coming back? A coolant leak rarely stays small losing enough coolant can push a hard-working diesel into overheating, and an overheating event can mean a blown head gasket, a warped head, a tow bill and a lost load. We pressure test the cooling system, trace the coolant loss to its source and repair the failed component for semi-trucks and heavy-duty fleets across Dallas–Fort Worth.

Why Is My Semi-Truck Losing Coolant?

Depending on what the inspection finds, the source may be:

• Radiator leak: core leaks, end-tank separation or physical damage can let coolant escape and reduce the radiator's ability to control engine temperature.
• Water pump leak: a failing water pump can leak from its shaft seal, weep hole or housing and because the pump circulates coolant, some pump failures can also contribute to overheating on their own.
• Hose, clamp or fitting leak: hoses, clamps, pipes, plastic fittings and connections deteriorate or loosen and commonly begin leaking when the system is hot and pressurized.
• Coolant reservoir leak: a cracked reservoir or surge tank, or a damaged connection around it, can cause visible coolant loss near the tank.
• Pressure-only leak: some leaks are invisible when the truck is cold and only open up at operating temperature and pressure which is exactly what a pressure test reproduces in the shop.

This applies to the trucks that work Dallas–Fort Worth every day Freightliner Cascadia, Peterbilt 579, Kenworth, International, Volvo, Mack and Western Star, with Cummins, Detroit or Caterpillar power. The visible symptom alone doesn't identify the failed component. Finding the source comes before replacing parts.

Signs Your Semi-Truck May Have a Coolant Leak

A coolant leak isn't always a large puddle. Some leaks only appear once the engine reaches operating temperature and the system builds pressure. Common symptoms include:

• Coolant puddles underneath the truck.
• Reservoir constantly getting low / frequently adding coolant.
• Low-coolant warning or engine-protection message on the dash.
• Temperature running higher than normal especially under load or climbing grades.
• Steam or a sweet coolant smell around the engine compartment.
• Visible coolant residue around hoses, fittings or the radiator.
• Coolant loss with no obvious external leak.

If your truck keeps losing coolant and you can't see where it's going, the leak should be diagnosed not managed by topping off the reservoir every few days.

What Waiting on a Coolant Leak Can Cost

Coolant is what carries heat away from the engine. The progression is predictable: leak → coolant loss → reduced cooling capacity → rising temperature → overheating. How fast it happens depends on the size and location of the leak and how hard the truck is working a truck that runs normal bobtail or empty may overheat pulling a heavy load or climbing a grade in Texas heat.

For an owner-operator or a fleet, that progression has a price:

• Engine damage: overheating a diesel can lead to a blown head gasket, a warped cylinder head or turbo damage repairs in a completely different cost category than a hose or clamp.
• Towing: a truck that shuts down loaded on the highway isn't driving itself to the shop.
• Lost loads and downtime: a derate or shutdown mid-load costs revenue, not just repair money.
• Repeat failures: topping off coolant without fixing the cause means the same problem comes back usually at a worse time.

We don't have to guess at your risk level: diagnosing the leak tells you whether you're looking at a minor repair or a problem that shouldn't see another loaded mile. A hose clamp found today is a fraction of the cost of an engine opened up next month. If your truck is already overheating right now, treat it as an emergency see our emergency cooling system & overheating repair page, or better: stop the truck and call us.

Coolant Leak vs. Radiator Leak Are They the Same Thing?

Diagnosing the truck for coolant loss is broader than assuming the radiator is bad. If the radiator is confirmed as the source, radiator repair or replacement becomes the correct repair path and if it isn't, you just avoided paying for a radiator you didn't need.

Coolant Leak or Water Pump Problem?

Water pumps commonly leak from the shaft seal or weep hole, which is one of the specific points we inspect. If diagnosis confirms the water pump, the repair addresses the pump not a generic "cooling system service." The chain matters: water pump failure → coolant loss and/or reduced circulation → temperature problems → overheating risk.

Losing Coolant but No Visible Leak?

This is the most common version of the complaint we hear: "My truck keeps losing coolant, but I don't see a leak." A cooling system pressure test reproduces hot operating conditions and reveals external leaks that are invisible in the parking lot. If the pressure test shows no external leak, the coolant loss may be internal and that requires further diagnosis before anyone starts replacing parts based on a guess. Either way, the test replaces assumption with an answer.

How We Find a Coolant Leak

1. Your description first: where you see the coolant, how often you're adding it, and whether the truck loses it parked, driving, idling or pulling a load. Whether the temperature has been creeping up.
2. Cooling system pressure test: we pressurize the system to reproduce hot operating conditions and trace where coolant escapes.
3. Component inspection: hoses, clamps, pipes and fittings; radiator core and end tanks; water pump seal and weep hole; reservoir, cap and connections.
4. Confirm the failed component: the repair recommendation follows the evidence never the other way around.
5. Written estimate before major components are replaced.
6. Repair, refill with the correct coolant spec, and verify: the job isn't done until the system holds pressure and operating temperature is normal.

The diagnostic path is: coolant loss → pressure test & inspection → leak source → failed component → correct repair. The objective is not to add more coolant. It's to make sure you stop needing to.

Semi-Truck Coolant Leak Repair in Dallas

Once the source is confirmed, the appropriate component is repaired or replaced. Depending on the failure found during diagnosis, that may involve the radiator, water pump, coolant hoses and clamps, fittings and connections, the reservoir or surge tank, seals, or related cooling-system components.

The repair required depends on the actual failure which is what prevents the cycle of refill → drive → lose coolant → refill again without ever correcting the cause. We work on Class 7-8 trucks: semi-trucks, heavy-duty trucks and box trucks, for owner-operators, fleets and dispatchers across DFW see all our semi-truck repair services in Dallas.

Real Cooling-System Work From Our Shop

A recent cooling-system repair at our Dallas shop: a 2022 Peterbilt 579 with a Cummins engine at 593,125 miles came in with a failed fan clutch a cooling-system component responsible for pulling air through the radiator and controlling engine temperature. Repair time: 3 hours, at approximately $1,200. The truck left with its temperature control restored instead of a parts-swapping guess.

Coolant Leak Repair for Semi-Trucks in Dallas–Fort Worth

Our shop is at 2323 Chalk Hill Rd, Dallas, TX 75212 minutes from I-30, Loop 12 and the freight corridors on the west side of Dallas. We diagnose and repair cooling-system problems on heavy-duty trucks every week: Freightliner, Peterbilt, Kenworth, International, Volvo, Mack and Western Star, with Cummins, Detroit and Caterpillar engines.

Hours: Monday–Friday, 7:00 AM–5:00 PM · Phone: 214-761-9082 · Same-day diagnostics when possible call to check today's availability.

Semi-Truck Coolant Leak Frequently Asked Questions

Related Cooling & Emergency Truck Repair Services in Dallas

Coolant loss often overlaps with other cooling-system and roadside problems. If the diagnosis points to a specific component or if your truck is already down these services connect directly with this page: