Thank you so much - incredible info and exactly what I was looking for! I really wasn't sure how long these things would last, but that gives me some confidence that you're up to 225K. I think I'll just leave it then and see how it goes.
180K... 225K... That's nothing on these things with basic maintenance. I've had mine since ~146K and have NOT been easy on it. I cammed it at 200K and have been spanking it even harder ever since. Mine's just a weekend toy and I'm not aiming to maximize its lifespan. We've had at least one 400K+ member here and a there are a few 300K+ members running around.
@89Suburban is one of the most active. I think
@Trey Hardy is over 300K, too. Personally, I don't consider these things "high mileage" until 200K. But "high mileage" does not equate to "worn out". There are a few maintenance/wear items that need attention around your Yukon's mileage, and all that has been covered here.
I'm planning on putting together a tool kit to take with me and I really didn't know where to start, so this is great! Anything else you think I should take with me?
I'm a fan of a telescoping lug wrench. In addition to the extras I have stuffed in the jack compartment, I have this:
https://a.co/d/cZnL7qj
Any recommendations on a good OBD scanner - as I'm starting to now do my own vehicle repairs, I feel like I need to get something good to go across 3 cars.
This is a whole can o' worms in itself better suited as it's own separate subject. If it were me, I'd buy a cheap one to keep in the Yukon for emergency use and buy a nicer one (if needed) to cover the other vehicles. For your Yukon, you should be well-covered with one of the Bluetooth models that plug into the ALDL and sync to an app on your phone. It's small, doesn't have a thick cord you gotta keep rolled up and stuffed in your center console, etc. There are plenty of options for these.
One question on the heater hoses - should I also replace the hose that goes to the radiator?
I think this was already covered, but, yes- "all the soft parts".
Also, what is the best way to make sure I get all of the coolant out of the system, make sure I get the air out, etc? I see conflicting videos - some say to keep the reservoir cap off and keep refilling, other people say don't do that?!? What's the best way to refill properly with new coolant?
Plenty of videos on this. I just keep the surge tank filled as it idles, comes up to temp and the thermostat opens. Then check it and top it off periodically over the next few drives as the air works its way to the highest point which is the surge tank. I buy the coolant concentrate and distilled water as it's the most economical method. You're paying for convenience with the pre-mixed stuff. Also, out of that gallon of pre-mix, 50% of it is just water and you're over-paying for it. After a complete system drain, I pour half a gallon of distilled water into the surge tank then half a gallon of coolant concentrate. Then I pour the remaining half gallon of the concentrate into the half-empty gallon water jug to mix it then pour that in as needed. Then I have an empty gallon jug to mix up more coolant as needed for topping off.
Last question on this one - how much time do you think I should set aside to do the heater hoses swap for a total rookie? I'm traveling for work the next two weeks, so I'm trying to squeeze it in between flights and want to make sure I can do it right!
1.5 - 2 hours, depending on how much you fight the connectors and/or how fast you work. It's all fairly easy access and straightforward.