Understanding Auto Part Numbers

Is Your Semi-Truck Overheating? 3 Common Radiator Problems And How To Fix Them

by Gwendolyn Anderson

When your livelihood depends on getting to your next destination on time, being sidelined with an overheating engine can be extremely frustrating. And as a trucker, you never know where you'll be when an engine problem occurs. You may not know where the nearest reliable semi-truck mechanic is, or you may simply not be anywhere near one. That's why it's a good idea to know how to solve some of the more common problems yourself. Check out some of the most common causes of steam pouring from your radiator, and learn how to fix these problems yourself.

Thermostat Failure

When you're not exactly sure what's causing the problem, it's not a bad idea to start with the simplest possible fix. Thermostat failure is a common cause of overheating, and it's not too difficult to diagnose the problem. Remember to wait until the engine is cooled before beginning work under the hood.

First, locate the thermostat. It should be located in the spot where the top radiator hose meets the engine. Remove the hose clamp, and remove the bolts that hold the thermostat in place. You're probably going to lose some coolant during this process, so you'll want a bucket underneath the truck to catch it.

Testing the thermostat to see if it has failed is simple. When you remove the thermostat from your cooled-off engine, it should be closed. Drop it into a pan of boiling water. Remove it after a few seconds. If the thermostat is working properly, it will be fully open, and you'll see a gap of about a quarter of an inch wide. If the thermostat is not working properly, it will remain closed or only partially open. In that case, it's a simple matter to buy a new thermostat and insert it in place of the old one. Make sure the new thermostat matches the old one exactly.

Radiator Hoses

If the thermostat isn't the problem, the next most likely cause of the overheating is a leak in one of your radiator hoses. Radiator hose leaks are more common than leaks that originate in the actual radiator. That's because these parts wear out faster than the radiator does. You can avoid radiator hose leaks by replacing the radiator hoses every five years or so – if they are older than that, they're likely the source of your problem.

To diagnose a leaky radiator hose, look for cracks and holes in the hose. To remove the hose, start by putting a bucket underneath the radiator and draining it. You can do this by removing the drain plug located at the bottom of the radiator. You'll need a flat-head screwdriver to remove the radiator hose clamps, and you may need to use a utility knife in order to completely remove the hose from the radiator. This is fine, as long as you don't damage the radiator.

Once you've removed the hose, all that you need to do is put the clamps on the new hose and attach it in place of the old one. When you're finished, make sure to refill the radiator with new coolant.

Radiator Leak

If you've determined that the thermostat and the hoses are fine, you're most likely looking at a radiator leak. The only permanent solutions to this problem are to replace the radiator entirely or to solder the leaks shut using parts of older radiators. However, there is a temporary solution that may get you to your next destination on time: cooling system sealer.

You can buy cooling system sealer at most auto parts stores fairly inexpensively. It comes in the form of powders or pellets. All you have to do is add it to the truck's radiator while it's cool, then drive it for 30 minutes or so until the radiator heats up. The sealant will expand and cover any small cracks, temporarily stopping any leaks.

Knowing how to small radiator problems while you're on the road can make the difference between completing a job successfully or not. The better you can handle small engine problems on the road, the more likely you are to successfully complete jobs and get more work.

To learn more about how to maintain your truck's radiator, visit Radiator Pros.