May 13, 2022—There is a pink liquid forming in the coolant tank of some 2021 and 2022 full-size GM truck and SUV models.
According to GM Authority, the presence of this liquid may mean that engine coolant has mixed with transmission fluid.
A recent post on GM's Techlink service site states that the source of the pink liquid relates to an internal leak in the automatic transmission fluid cooling exchanger. This leak is what presents the opportunity for coolant and transmission fluid to mix.
GM refers to the liquid has having a "strawberry milkshake appearance".
This discolored coolant has the potential to cause several issues. The coolant reservoir has the potential to become overfilled, the engine could experience overheating and the transmission performance may be affected.
Bulletin #08-07-30-035 shares that this issue can be fixed by disassembling the transmission and replacing the automatic transmission fluid cooling exchanger. Additionally, the coolant system should be flushed.
Although a recall has not been issued by GM, the following 2021 and 2022 models of these vehicles may be affected: Cadillac Escalade, Cadillac Escalade ESV, Chevy Silverado, Chevy Tahoe, Chevy Suburban, GMC Sierra, GMC Yukon, GMC Yukon XL.