How To Service Your Chevy's Cooling System

In order to keep your GM’s cooling system in good operating condition, you need to service the cooling system — this means regular maintenance as well as routine inspections. Here’s what you need to know about servicing your vehicle’s cooling system to keep it working as it should.

An efficient cooling system requires:

  • Adequate amounts of coolant
  • Efficiency in the heat exchanger
  • A fan that pulled air through the radiator at low speeds
  • The water pump to keep coolant moving
  • Thermostat to regulate temperature

GM cooling sys service

Check Coolant Level

Keeping an eye on your coolant level will prevent it from overheating due to low levels of fluid. Levels should be checked at the reservoir and not the radiator because the radiator only siphons coolant as needed. It’s normal to find it to be a little low on occasion, but significant loss indicates a leak in the system.

If the coolant is low and you don’t spot and visible leaks right away, do a pressure test. If the system holds pressure, make sure the cap is correct for your car and is on snuggly. If it doesn’t hold pressure, you likely have an internal leak. Check the oil for signs of water that would indicate a cracked block or blown head gasket.

Should the coolant be low with no obvious cause, it may be due to a one time instance of overheating — however, you should keep a close eye on levels for a while.

Measure the Strength of the Coolant

Check the mixture of the coolant to prepare your vehicle for temperature changes. A 50/50 mixture of antifreeze and water will provide enough boiling protection and freezing protection for most conditions. In extreme conditions, you can increase the antifreeze levels, safely, up to 65% — anymore and you’re inhibiting the cooling system’s ability to carry heat.

Inspect the Condition

You can learn a lot about the cooling system by inspecting the condition. What you’re looking for is signs of corrosion, sludge, and a noticeable change in coolant color. Any of these should signal that it’s time to flush the system and keep the service intervals much shorter than before.

Flush the System

Flushing the system is the best way to clean out the system, although there are other ways of refreshing the cooling system. This method removes most of the old coolant from the block and dislodges deposits that can clog heater cores, radiators, and get in the way of proper heat transfer. Merely draining and refilling leaves up to 50% of the coolant behind.

Servicing the Radiator

The radiator has a service life of six to ten years for copper/brass radiators and six to ten years for aluminum radiators. Even with regular service, radiators can fail from damage — they’re somewhat sensitive to physical stresses, so don’t be surprised if replacement is needed. If this is needed, make sure to only used genuine GM parts as cheap aftermarket radiators are known for causing cooling system issues!

Cooling System Tip!

If your engine overheats after refilling the cooling system, especially after flushing, air may be trapped under the thermostat. Many people drill a small vent hold un the thermostat flange to prevent this.

Follow these service tips and you’ll prolong the life of not only your cooling system, but your engine! Replace parts as they wear and keep on top of your coolant levels and you’ll be set for many years.