After driving our coach some distance the last month, following a 3 year hiatus and being cognizant of this thread, I've paid more attention and can report that almost every time I engage the Exhaust Brake there is a reaction in the steering wheel. At road speeds it may be little more than a slight movement, but it's there nonetheless. Going down hills of course is where the EB is most often engaged, and where at the same time is a lowered RPM as the foot comes off the throttle at the top of the grade. The lower RPM seems to result in a little stronger steering reaction, albeit nowhere near as strongly as when at minimal throttle in a parking lot or campground maneuver.
This all supports the theory that BCS put forth for Russ Mann's coach. My question for the mechanics here, like Dave A. or Gerald: why does the hydraulic cooling fan kick in by apparent default when the exhaust brake is activated? I'm not questioning that it should or shouldn't, but rather curious about the physical, mechanical necessity. I'm presuming that exhaust backpressure increases engine temp., especially at lower RPM's, and the ECM automatically pre-anticipates the heat, or is it some other reason?
I've yet to drop in on a CAT facility for the recommended reprogramming. I intended to, but elected to have Henderson's do the engine service while I was there for other work. They were not aware of this issue, so I didn't have them address it. I'm presuming that reprogramming so the cooling fan doesn't automatically initiate with the EB won't affect the normal cooling fan engagement at its normal high temp points.
Thanks,
Joel