Count me in as part of the leak club. My AT4 build date is 8/20. Thought I'd be lucky but seems like a design flaw with all of them. Hopefully my repair will fix this the first time because I love this truck otherwise.
New member here...hopefully this helps someone.
2020 GMC Sierra AT4 3.0L
Carbon Pro Package w/20in carbon grey wheels
MSRP $66,475
Negotiated Price before TTL $55,500
About the best deal I could find in Texas. Not many AT4 carbon pro diesels around here.