How to Replace Thermostat Housing 2000-06 GMC Yukon

Remove this cover, I'm gonna use an 8-millimeter socket. Loosen that bolt up and slide the cover out. And loosen up this worm clamp, you can use an 8-millimeter socket or a straight blade screwdriver. And the same with this one right here. Use a trim tool and just separate this retainer right there with that bracket. Now slide the snorkel off there and pull it out. Just to gain more access, I'm gonna pull this airbox off. Disconnect the mass air flow sensor. Grab the airbox, pull it straight up, then you can slide it out. There's two tabs, and this holds it in. I'm just gonna take the cap off the coolant reservoir, set it aside.

I'm gonna take the bottom radiator hose off. I need to drain the coolant, there's no coolant drain on this radiator. So I'm gonna use a hose clamp pliers that have the cable style. Remove that hose clamp. Make sure you have a drain bucket underneath. Squeeze that. And just let that drain out. Now I'm gonna take this hose off, just use some hose clamp pliers. And let's twist the hose a little bit. If you can't get it to break free just use a 90-degree pick, try to get underneath there, or a hose pick. Slide the hose off. There might be a little coolant in there.

Now there's two bolts, one here and one underneath the housing. Use a 10-millimeter socket, take those bolts out. So take both of those bolts out, should be able to slide it off. Keep the drain bucket underneath because it'll probably spill some more coolant out, and get it out. Just take a rag, just clean this area up. If you have a lot of corrosion on here just use a razor blade or a scraper, scrape some of that off, or even a wire brush. Now take the thermostat and housing, slide it in position. And take the two bolts, get them started. And torque these bolts to 11-foot-pounds.

Now take the hose, line the hose up with the clamp, use the hose clamp tool. And if these clamps seem weak, then replace them with a worm clamp. And slide the airbox back in position. What you want to do is slide this piece, that's gonna go right here. It's gonna slide there and then push the two pushpins straight down. Push down, it's good to go. Reconnect the mass air flow sensor. And put the snorkel back on. Line this up with the throttle and the airbox. And tighten up the worm clamps. And line this bracket back up. Put the cover on, slide it in the back, get the bolt started, snug it down.

Now you want to fill up the coolant reservoir. I fill it up about an inch or two above where the fill line is before we start the vehicle and start the vehicle with the cap off. And the level is gonna adjust, it's probably gonna suck some into the engine and then after that you're gonna adjust accordingly. Let the vehicle run for about 10 minutes, monitoring the level. While you're letting it run, monitor the temperature gauge, make sure it does not go over 210 degrees. If it does then shut the vehicle off. Let it cool down, top off the coolant and try it again.

Turn the heat on, put it on medium fan. Turn the heat all the way up to hot. Make sure you do feel some heat coming out of the vents, especially when the temperature starts getting up there. If you don't feel any heat, again your coolant level is gonna be too low, shut the vehicle off, top off the coolant. And then after that, after the thermostat has opened up when the hoses are nice and hot, shut the vehicle down, adjust accordingly, put the cap back on and you should be good to go.