The draft control on the 1135 works off of the toplink. It has to be connected for it to work. I had an 1155 and never was happy with the draft control on it. I finally took the draft spring plates off and welded up the toplink pin boss where it couldnt move.
As tated the top link needs to be connected. My 135 wasn't working right until I took the top cover off and rigged it correctly, it was obvious someone had tried before and either gave up or was reading the clearances all wrong. Now that it's back together it works well.