Originally Posted by SSteve
It's good to be the King--er--I mean have a good shop and tools. Nice concrete floor, work bench and, I assume, a big honkin' air compressor and impact driver. All are on my Christmas list.
Any thought about my issue occurring after reconnecting the PAC brake (see my OP)? I've heard that if the ABS has an issue, the PAC brake is disabled. Can the reverse be possible?
I'm appreciative of your nice comments. My "shop" is only two things. One, where the pictures were taken, is only an outside patio that, sits alongside the house and, we put one of those "Swap meet" style covers up, over the motor home. Yes, it provides a good, clean, level, IN THE SHADE , work area/space for working on the big beast.
Second, the "shop" you see with the clean parts is only our garage, which is attached to the house, just in front and to the left of the motor home parking spot. I wish I had a "Shop" that was separate from the garage that I could do the work in. I've been a "DIY" back yard mechanic for 50 years! What's that tell you about my age??
And, as a note here, my air compressor is only a 30 gallon 2.5 HP Sears unit. And it ain't one of those junky "oiless" types. But, I don't use it for the big lug nuts on the coach. I use a tool I purchased from ebay called a "torque multiplier". Its got a planetary gear reduction ratio in it of, 70:1. I can break those 450 lb. lug nuts loose, sitting on my duff, with one arm.
Most of the stuff I've done on this coach is kind of fun. But, much of it has been a serious pain in the a$$. All of it has been an immense learning experience. You ought to see my maintenance records. As for the pictures, I just hope some on here get an idea of what to look for if and when they take it upon themselves to do any kind of wheel/seal/bearing/sensor/brake work. It's all big, heavy stuff so, take all the precautions for protection of your back etc.
Anyway, to your topic. The ABS module, is a very complicated, seriously fast thinking system. I have no clue on how it works. I do know there's sensors on each wheel, and rotating rings to work with those sensors. The ABS module is, on our coach, located on the inside of the passenger side frame rail, just over the differential. It is tied to the front instrument panel system via what's called the "J-1939 Data link". Also tied into that data link is your engine ECM, the transmission ECM, and, depending on year model of coach, what's called the MMDC is, also tied into it. The MMDC, also known as, the Multi-Module-Data-computer, takes info from all the modules tied into that data link, and desiphers it to digitally send it to all your gauges. And, that includes the "annunciator panel" (also known as the light bar) too.
The exhaust brake, as well as cruise control and multi other bits of info and, what's known as "requests", are all tied into the engine ECM. So, if the ABS has a problem, the engine ECM takes that info, processes it, and takes appropriate action. And in your case, the decision make by the engine ECM, may be limiting or, shutting down your operation of the e-brake. Now, I'm not an expert in any of this. I just learn(ed) as much as I can, if and when I have issues.
You know, I'm retired and figure I've been to school, on and off for well over most of my life and career. So, I figured I'd "quit" the schooling part after retirement set in and just have fun. Well, because of certain thing that have happened on this coach, I've "schooled" myself on so many of these systems that I never thought I would have.
Anyway, sorry for the long winded novel here. All I can say is, do what you can to learn about how your ABS system works, how it's analyzed, and possible remedies that, as layman, you can fix yourself. That is of course, if you want to do it yourself. Good luck.