How to Check for Cooling System Leaks in a GMC Sierra

Checking your GMC Sierra for cooling system leaks is necessary, if you want to prolong its useful life. Catching these leaks early can save you money and effort, because an unchecked leak can cause engine overheating or failure. One way to stay abreast of this problem is to examine your usual parking place for signs of leaks. However, there are better methods and they're almost as simple.

Instructions

1

Open the hood to inspect the hoses, which connect the engine to the heater core and the radiator to the engine. The heater core on a GMC Sierra is behind the engine and near the windshield. Check for any bulging, cracking or splitting in the hoses as well as any noticeable signs of coolant leakage. These signs can take the form of corrosion, discoloration or wet spots from fresh coolant.

2

Use a flashlight to examine the radiator completely for any signs of a leak. Again, these signs are corrosion, discoloration or freshly leaked coolant. Inspect the bottom part of the radiator carefully, because rocks and road debris can damage the radiator during the normal course of operation.

3

Check the water pump and shaft seal for any possible signs of leakage. The water pump on a GMC Sierra is behind the engine fan and connects directly to the engine. The shaft seal is what secures the connection between the water pump and the engine block. Look for any corrosion or discoloration to confirm the source of the leakage.

4

Remove the radiator cap and add fresh coolant to the radiator to within an inch of overflowing. Be sure to touch the radiator to make sure it's cooled down before opening it. Never open a warm or hot radiator, as it can explode, spewing hot coolant over anyone in the area.

5

Start the engine of the GMC Sierra, set the heater to high and let it run for about 15 minutes. Next, switch off the engine of the GMC Sierra to examine the water pump, shaft seal, radiator and hoses for leaks one more time. If you still can't locate a leak, it may be an internal cooling system problem and you need to take the SUV to a cooling system specialist for further diagnostics.