How to Drain & Replace Engine Coolant for the 2005 Silverado

by Justin Cupler

The Silverado line of Chevrolet pickups arrived in the 1999 model year, alongside the classic C- and K-series of pickups. In 2005, the Silverado came in three sizes -- 1500, 2500HD and 3500HD. These sizes indicated 1/2-ton, 3/4-ton and 1-ton, respectively. Chevrolet filled the 2005 Silverado's cooling system with long-lasting Dex-Cool coolant. Chevrolet recommends draining and refilling the cooling system every five years or 150,000 miles, whichever comes first. The 2005 Silverado's radiator does not have a drain plug, so draining the coolant requires removing the lower radiator hose.

Step 1

Open the Silverado's hood and loosen the coolant reservoir cap until you hear a hissing sound. Stop loosening the cap until the hissing sound stops. Once the hissing stops, remove the cap from the coolant reservoir tank.

Step 2

Raise the front of the Silverado, using a floor jack, and position jack stands under the frame rails. Lower the truck onto the jack stands.

Step 3

Crawl beneath the front of the truck and find the lower radiator hose. Set a drain pan under the connection point between the lower radiator hose and the radiator. Squeeze the tabs on the lower radiator hose's clamp with slip-joint pliers, and slide the hose clamp about 3 inches up the hose -- away from the radiator. Pull the lower hose from the radiator, using a slight twisting motion. Be prepared for a fast flow of coolant from the hose and radiator.

Step 4

Press the lower radiator hose back onto the inlet on the base of the radiator, once the coolant stops flowing from the hose and radiator. Squeeze the tabs of the lower radiator hose's clamp and slide the clamp to about 1 inch from the end of the radiator hose, using slip-joint pliers.

Step 5

Raise the truck off the jack stands, using a floor jack, and remove the jack stands from under the Silverado. Lower the truck to the ground.

Step 6

Trace the upper radiator hose until you locate the thermostat housing -- the metal component connecting the hose to the engine. Loosen the bleeder valve -- the 1/4-inch brass valve -- on top of the thermostat housing, using a combination wrench.

Step 7

Pour 50-50 premixed Dex-Cool coolant into the coolant overflow tank until the coolant level reaches the "Full Cold" area on the reservoir. Tighten the bleeder valve, using a combination wrench. Close the coolant overflow cap.

Step 8

Start the engine and increase the truck's engine speed to 2,000 to 2,500 rpm, and hold it there until the engine reaches operating temperature -- about halfway up the temperature gauge. Allow the engine to idle for about three minutes and shut the engine off.

Step 9

Allow the Silverado to set until the engine is cool to the touch. Loosen the coolant overflow cap and stop loosening if you hear a hissing sound from the cap. Once the hissing sound stops, remove the cap from the overflow tank.

Step 10

Add 50-50 premixed Dex-Cool coolant to the coolant overflow reservoir until the level reaches the "Full Cold" area on the reservoir. The 2005 Silverado's cooling system holds 3.8 to 6.7 gallons of coolant, depending on optional equipment. Tighten the coolant overflow reservoir cap.