Goldy I'll tell ya another story. As MWMULES stated, look up the TM for the M105A2 here, follow the TM, and do a PM on your trailer. If your trailer has one, pay special attention to the separation valve (picture). They can go bad internally and your brakes will perform poorly. It's an inconspicuous item that is easily overlooked. I assume you'll be pulling your trailer with an MV, so, hook up your trailer, turn on the air, and if you don't hear any air leaks, press down on your trucks brake pedal and then let off on the pedal. You should hear a noise similar to a baby crying. That means your separation valve is working, and probably your brakes as well. I had poor braking performance after I rebuilt my trailers brakes. So I used this test to check my separation valve, and the separation valve was quiet. I replaced my separation valve, and now it cries like a baby, and my brakes work. Hope this helps, and good luck with your new trailer.