Having an issue with the trailer brakes being very touchy, they seem to apply pressure sooner than the tractor. Not so much of a problem when loaded but empty I'm burning rubber often times causing tires to flat spot which causes vibration.
Anyway, I've talked to someone who has told me that it is a proportioning valve on the truck but I'm not sure of its location. Im asking because I got 2 different takes on the problem.
1st was a modular value underneath the 5th wheel
2nd was a valve located at back side of the cab, driver side where the trailer parking and service air hoses are screwed in.
Anyone knows for sure which one is it, Im trying to avoid throwing parts at it since its either hard to find them or they are expensive. Appreciate your help.