Benz43new

Hey, just doing some personal maintenance after picking up a used 1999 C43. Have fixed a couple of things already but am wanting to try the Multi contour function. Went to pull the back of the seat off and didn't realize it was so easy, it just had two clips on the top that pop out and it folds down partially. Noticed there was a disconnected hose on the Y splitter. Pushed the hose back in but still not working. I do not hear any hissing of any sort as mentioned in other threads so not sure if I need to check the pump or what. Any help or input would be much appreciated. Thanks