air brakes - when to use when not too???

Trailer experts
I have a M1061 trailer which i pull behind my M936a1. everything is stock. I have noticed if i run the trailer empty with the air brakes hooked up, on anything other than pavement, they will lock up pretty easy. once loaded, the brakes operate perfectly. I have not run it on wet pavement empty - but that is my concern!

So my question is - are my brakes out of ajdustment? or should i run no brakes when empty?

thanks

They are air over hydraulic. They are sensative with the air flow. Try running it with the valve halfway open or even a quarter. it may alleviate that. Or add in a trolley valve so you can add only however much air to the brakes that you want. Trolley valve install takes about an hour to hook up on the truck. I have a video on my youtube page on it. and really the M936 doesnt need brakes to stop that little 1061 but even a little is a help. Especially the time you load it up with logs and forget to open the service brake side and you get a push. Even though a heavily loaded m1061 couldn't push a 936 very much, but something to keep it in track it a little better than nothing. Trolley valve also helps with backing it up too.

Simp5782, will add a trolley valve to my list of things to do. and yes I have noticed no push even when loaded with a couple of tons of logs and no air on the brakes (just local < 45 mph).
thanks