2018 Yukon XL 4x4 38k miles leaking coolant

[Msuforeman]

I moved my wife's Yukon last night and there was a large puddle of coolant under it. The reservoir was down about 3/4 gallon. I filled it back up and ran it as well as let it idle parked for 20 mins and no drips anywhere. Y'all have a clue what's going on?

Thanks!!

 

[Big Mama]

Loose reservoir cap? Did you get a recent oil change from a ****** lube place?

 

[Msuforeman]

Loose reservoir cap? Did you get a recent oil change from a ****** lube place?

It was tight when I checked it and I do my own oil changes.

 

[Big Mama]

Thought so. Any cracks in the reservoir? Sounds like it had to be under a good bit of pressure to loose that much. Have you been under it yet to trace the leak? Near driver or passenger side? Front or firewall? Heater all the way on and off?

 

[Msuforeman]

Thought so. Any cracks in the reservoir? Sounds like it had to be under a good bit of pressure to loose that much. Have you been under it yet to trace the leak? Near driver or passenger side? Front or firewall? Heater all the way on and off?

I used a paper towel to wipe around the bottom but it was dry. Yes I have been under it and can't find where it originates from. I topped it off the other night and it hasn't leaked again. Very weird.

 

[Big Mama]

Chalk it up I guess though I hate doing that. She didn’t notice any lights from heat or low reservoir?

 

[OR VietVet]

Do you have the means to pressure test the system?

 

[Msuforeman]

Chalk it up I guess though I hate doing that. She didn’t notice any lights from heat or low reservoir?

Nope--No lights.

 

[Msuforeman]

Do you have the means to pressure test the system?

I do not. I guess I will just watch it and then take it to the dealer if it happens again.

 

[OR VietVet]

You can get universal pressure testers at ebay for around $50. Lots of attachments.