This bulletin applies to 2007-2012 Cadillac Escalade, Escalade ESV and EXT, 2007-2012 Chevy Avalanche, Silverado, Suburban and Tahoe, and 2007-2012 GMC Sierra, Yukon and Yukon SL vehicles with four wheel or all-wheel drive.
The front axle vent hose is mounted on the left side of the engine compartment and may not be correctly routed. The vent hose can get misrouted and placed in a position that is lower than the front axle harness/engine harness in-line connector. In this position, the vent tube may ingest water. The front axle vent hose may be routed to the wheel side of the wheel well. It may be hanging through the opening of the wheel well in a vertical position with the vent cap hanging down.
If you encounter a misrouted vent hose, re-route to the correct location. The hose should be mounted inside the engine compartment in an upward position to prevent the possibility of water being drawn into the hose and axle assembly during cool-down. Tape the vent hose to the nearby wire harness. If the hose needs to be re-routed, it is advisable to also change the front axle fluid.