My 2009 suburban automatic lift gate will open half way then close again and when you open it all the way manually it will not stay open and just slams shut like the pistons are not working. Any suggestions.

Thank you,
Phil

 

It's a simple fix. Your lifters have worn out. I got a new set on Amazon. Very easy to replace. Have someone hold the gate while you remove old ones and put in new ones. 2 minute job. There's a little tab on the ball you lift, then remove. Then pop on the new ones and Voila! Problem solved! You may have to replace the lifters on your glass window shortly also.
I recommend the Strong Arm brand on Amazon.