Two Position Jake Brake Switch - Any difference between up and down?

[EngineerMike]

Bill- there is a difference on Hi/Lo but I have to get my micrometer out to find it. On a really steep hill, the rate of deceleration is slightly higher on Hi, but there isn't enough difference to feel. I'm theorizing that the VGT is like an exhaust brake (that's what the Cummins factory rep said) so that (here comes the theory) back pressure builds up & wasting of the engine's compression is less efficient. So the Jake effect is less under any circumstance, and VGT effect sort of swallows the feel of both Lo and hi Jake. No idea if that holds water.

Redlands decided they didn't like the pedal feel on the Alpine they were 1.75-ing, so they put the 2" back on. I have an email in to Keith to figure out what that means (I heard it thru PM from the coach owner). Will report further progress when such exists.

[OldForester]

You probably have the theory right on the VGT. I thought it might act like an exhaust brake, building back pressure. I would think the main idea is how much real slowing do you get. If we were sided by side on a steep hill on the freeway with our 36's we could put them both at hi at the same speed and see if mine slowed a lot more than yours. Of course we would have to be somewhat even in total weight to get a feel for that. But you probably remember pretty well what your '06 felt like.

I had talked to Keith at RTS about having the 1.75 mod done to our coach in January when I have them flush the brake fluid and clean/lube the pistons and calipers like they did last time. He said at that time they were still working the 1.75 mod and had not got it working the way they want it, but were going to try some other ideas. So I guess they decided to go back to the 2" while they worked some more on the concept.

I'm not unhappy with our brakes, but thought if that MC mod works, I would be interested in doing it, because more braking power is usually always better.

Will be interested in your further progress. I'm going to get the coach back from storage tomorrow and get ready for my annual 6 weeks of deer and elk season. Nothing an old forester likes more than being out in the woods each year during hunting season hunting the timber and scouting the fresh clear-cuts. Maybe by the time I'm finished you'll have that brake mod figured out!