But that being said, I found out about that little T valve on the side of the pump, when of all things my brake switch failed. Now BMW in their herculean attempts to make everything idiot proof, put the roof switch behind you so its difficult to raise the roof doing 90 down the freeway, which of course would be disastrous for anyone behind you..So you have to have your foot on the brake as well, because obviously someone
had tried it...BUT, its not completely idiot proof, because you can still attempt to put the roof up with the tonneau cover fitted. Not that I ever attempted it...
. So the little T valve turns the roof from Hydraulic power , to Weetbix assisted...