I've got 3 trucks now( 2012 GU, and two 2022 LR) that in the past year have intermittently started dumping air out of the ABS modulator exhaust ports only with brakes applied (parking brake released/applied makes no difference). I have learned that replacing the modulators right off the bat was not exactly the best way to do things, as they started gushing air again within a month. To be clear; it is only ever 1 at a time. If i replace that one, the other side will leak. Bendix troubleshooting hotline suggested it was an electrical issue. However, all modulators and connections were within spec. I removed the supply line from the brake chamber and it still leaks. I have replaced the inversion valve on one of the trucks to see if maybe it was just a sticking check valve, as that was the 3rd point to leak on that truck after replacing the modulators. That leak has remained intermittent as well. I usually don't get hung up on something this long, or just throw parts, but my brain is making smoke now. Anyone have any advice?
