How To Replace Coolant Overflow Bottle 01-06 GMC Sierra 2500

Difficulty: Intermediate · About 35 min · Gmc Sierra

Replace the coolant overflow bottle on a 2001–2006 GMC Sierra 2500, working only with a cold cooling system and refitting the intake box afterward.

Steps

1. Wait for the engine to cool

   Park level and let the engine cool completely before opening the coolant bottle. Never remove a cap while the system is hot or pressurized, and collect any spilled coolant safely.

2. Move the airbox and hoses

   Loosen the intake-hose clamp and move the airbox aside. Release the bottle hose clamps and disconnect the hoses, plugging or containing them without damaging the hose walls.

3. Remove the old reservoir

   Disconnect the level-sensor plug and remove the bottle fasteners. Lift the bottle out and pour its contents into an appropriate container for proper disposal or reuse only if clean and approved.

4. Install the replacement bottle

   Connect the hoses and sensor wiring to the replacement, then mount the bottle and reinstall its fasteners. Reconnect the intake box and seat the intake hose fully before tightening its clamp.

5. Refill and inspect

   Fill to the cold mark with the specified coolant and secure the cap. After the engine warms and cools fully, recheck the level and inspect the hoses, bottle, and sensor for leaks.

Check your vehicle’s repair manual for exact specifications and fit.