Q: Steering wheel hard to turn; car squeaky

Hello, I have recently encountered this steering problem in a Chevy Avalanche, which is very similar vehicle to your GMC Yukon. Rest assured that all the symptoms your car is experiencing are likely connected to one thing, the power steering. In the previous situation with the Chevy, I recommended a thorough flush of the power steering system. When you remove the old fluid and replace it with new fluid, then add Lucas power steering treatment, it can aid in restoring life to your Yukon’s power steering system. In that case, and in most cases previously, this flush corrects the symptoms the vehicle is experiencing during turns and reversing. However I must note that there may be situations where the entire power steering pump will need to be replaced. It is very important to have certified mechanic inspect your GMC Yukon in person to diagnose the problem with the power steering pump and get you back on the road safely.