Car + Garage
Expert advice on repair, maintenance and gear. Change your coolant
If you buy one special tool, you can change your own coolant in about an hour—and save!
In the old days (the ’90s and earlier), changing your vehicle’s coolant was simple. Then cars got more complex and DIYers got intimidated by the precise filling and “air-bleeding” procedures required to eliminate engine air pockets. All it takes to get back in the game is a one-time $90 investment in an air-powered refilling tool. Then you can change your coolant yourself in about an hour. You’ll save about $50 on your very first coolant change, and about $100 on each one after that. This procedure works for any cooling system that’s not contaminated with rust or oil. I’ll show you how to check yours and then how to change the coolant.
Start the inspection when your engine is cool. Remove the radiator or coolant reservoir cap and examine the coolant color. If it looks rusty (don’t confuse orange coolant with rust), has crud or oil floating on the top, or looks like chocolate milk, call it quits and take your vehicle to a pro. You have problems that this procedure won’t solve.
If the coolant looks clean, start the job by jacking up the vehicle and supporting it with jack stands. Next, place a large drain pan under the radiator. Loosen the lower radiator hose clamp with pliers (springtype clamp) or a screwdriver (worm-drive clamp) and remove the hose (Photo 1). If the hose won’t budge, use a hose removal tool (one choice is Tool Aid No. SGT13860; about $8 online) to break it loose (Photo 1). Let the radiator and water pump drain completely. Then reattach the lower radiator hose and clamp.
Next, find and remove the block drain plugs (their placement varies, so refer to a repair manual for the location of yours). Reinstall the block drain plugs and move on to the refilling step.
Refill with fresh coolant
Insert the air tool (we used the UView 550500 AirLift II Economy Cooling
System Refiller; $90 online) into the radiator neck or overflow bottle. Connect the exhaust hose and compressed-air line and route the open end of the tool’s exhaust hose into an empty gallon jug or pail. Then open the valve and let the vacuum rise until the needle reaches the edge of the red zone on the gauge. Then fill with coolant (Photo 2). The vacuum sucks out any air pockets as it refills the system. When it’s full, just reinstall the radiator or overflow tank caps, remove the jack stands and go for a spin.
1. Remove the lower hose
Slip the pointed end of the removal tool all the way into the end of the hose. Then pull it around the radiator neck to break the hose loose. Then pull it off quickly and immediately direct the coolant into the drain pan.
2. Vacuum-fill the cooling system
Insert the fill tube into the coolant bottle. Then open the valve and let the vacuum pull fresh coolant into the system. Repeat the procedure until the system is full.
Hose removal tool Lower radiator hose
Valve Air-powered refill toolRadiator neck Fresh coolant