A couple of readers have e-mailed me with questions about braking and auxiliary brake systems for RVs. Keeping in mind that I am not a technical person, I’ll share what I told them, and I welcome your input as well.
Two readers questioned me about my comment in a recent blog about not using an engine brake on wet roads. Kay said her husband had driven truck for years and had not heard this, and Chris said they were coming down a five mile long 7% grade in Oregon with blowing wet snow, and they used their engine brake all the way down. She asked for information on why and when the engine brake should be turned off.
First of all, for our purposes, I use the term exhaust brake, engine brake, and Jake brake interchangeably. They all work a little differently, but all are designed to slow a diesel vehicle down, using the engine’s compression.
As I understand it, if you let off the accelerator on a wet road and the exhaust brake comes on, it can cause the rear of the vehicle to slide. Here is a link to a Department of Transportation article that includes a warning not to use an engine brake on wet roads:
And here is a discussion on the topic on the FMCA forum: http://community.fmca.com/topic/665-exhaust-brake-vs-retarder/
And also, an article from a trucker’s website that discusses mountain driving, and cautions about not using an exhaust brake on wet roads: http://www.newbiedriver.com/articles/mountain_grade_info.htm
But what do you do if you are on a road like Chris described above? Do you go down a steep grade in the rain or snow without the help of the exhaust brake and run the risk of building up too much speed, or do you use the exhaust brake and run the risk of a skid? I’m not sure. I’ve done it both ways, and survived. The main thing is keeping your speed down to start with. The old trucker’s rule was that you always go down a grade in the same or lower gear than you went up it.
I’m a wimp when it comes to mountain driving. In my years publishing small town newspapers in the mountain west, I have covered way too many accidents where truck drivers lost control coming down a steep grade and went over the edge. I’m perfectly content to get over in the right lane and creep down a steep grade, letting faster traffic pass me by. It may take me a few minutes longer to get to the bottom, but getting there in one piece is my priority.
Another blog reader questioned me about auxiliary braking systems for towed cars, and what the legalities were from state to state. Some states require an auxiliary brake on a towed vehicle and some don’t. Check the individual state’s Department of Transportation for details.
However, in my opinion, anybody who does not use an auxiliary braking system is asking for trouble, no matter what kind of motorhome they drive, and what kind of toad they pull. For years, we pulled a Toyota pickup behind our MCI bus conversion, and did not use an auxiliary brake. I always figured that the bus was plenty heavy enough to stop the Toyota. I was wrong.
We were in a small town in Alabama when a fellow ran a red light in front of us, and I had to slam on the brakes. The Toyota ended up sitting on top of the motorcycle rack on the back of our bus. Fortunately, there was no bike on the rack at the time, and the only serious damage was to the rack and to our tow bar. But it could have been much worse, and we learned a lesson from the incident. We now use an SMI Air Force One auxiliary brake, which uses our Winnebago’s air brake system to activate it proportionally. I wouldn’t want to pull out of a campground without it.
Thought For The Day – There are old pilots, and bold pilots. But there are no old, bold pilots.