This may not apply, but one thing I noticed on our camper when we got it was that the brake wires at the trailer axles were in contact with the springs. I would expect if that is common, it could be pretty likely that the spring could wear through the insulation and cause issues.
May not be the cause, but may be worth checking.
2016 Jayco Eagle HT 29.5BHDS (ordered 12/30/15, delivered 3/8/16)
2015 F-350 crew cab, short bed, 6.7L PSD, Pullrite Superglide 3300 hitch