u/CandleAcceptable1404

I purchased an old Fleetwood E1 pop up camper and have made a lot of upgrades to it for boondock camping like lithium, solar, various repairs etc. I attempted to install a DIY mechanical parking brake and I’m having issues getting it to bite down enough to actually stop the trailer from rolling. I purchased Dexter “parking brake ready” electric brake assembly and a generic parking brake cable/housing and a generic lever. Install was easy. I even cut a cheater bar from tubing to get more leverage. What’s wrong here? Anyone attempt something like this?

Not sure if this is the appropriate sub or not.