W202 Vacuum PSE

[nikki]

I have searched for this answer to no avail. The images below show the main vacuum junction for the PSE and rear door. Problem is vacuum pump cycles while driving, so far replaced only PSE pump with used one - this did not help. So I suspect door actuator issue. I am trying to figure out how to disconnect the yellow tubing from the main connector and the door so I can check the vacuum levels. Any advise of where to check the vacuums would be greatly appreciated. My thought was to heat the tubes with a heat gun but I am afraid of either melting the tubing or deformation of the tubing.