Electric over hydraulic brakes

The breakaway test is a great idea. The unit has only been pulled 500 miles when new and in storage the remainder of the time. All disc's and rotors are in great shape and move freely

The truck setting is a good point - I will check that out and hopefully thats the issue.
I have bled plenty of brake systems in the past but never a electric over hydraulic one. I will have to study up on that before starting.

Thanks

Easy check to see if it's truck or a trailer problem is to pull the break away switch and see if the trailer brakes lockup.

Denny

you should be able to lock up all wheels. something is very wrong. guessing from here is just that, a guess. I would start by checking fluid in pump and then bleeding brakes. Is the pump running fully or is it running on lower voltage than it should? Could have undersized wire and a big voltage drop? Controller could be bad. How about going to a deserted place and have someone in the bed pull the breakaway switch at a low speed and see if tires lock up. Are pads free and able to move properly? Are pads good or totally worn? All good questions with answers only available from you.

Our 2016 has setting for Elec and Elec over Hyd. and low med high braking effort as well as the 0-10

If you have 3 axles with Dexter disc (large pistons) brakes a second or larger pump maybe needed.

Also check to see if the brake were bled properly.