I had a similar question after reading this thread yesterday. I am getting ready to tow a Dodge nitro (6000#) with the engine in idle and have ordered a ready break system to combine with a blue ox package. So I called ready break and was assured that contrary to what most people think, the ready break system will actually work better with the power brakes active than with them off. The surge break will not have to work nearly as hard, and will only apply as much force as needed to do the job. Hopes this helps you, it put my mind at ease. Also they assured me the extra link between the receiver and tow bar will not weaken the tow system.