Originally Posted by SteveS
When I switch between hi and lo on the brake, if I use my imagination I can tell a difference. They both seem the same to me and even when I put it i low, the hi illuminates. Neither position seem to provide significant braking...at least not as much as my previous RV had with a Cummins 8.3.
Steve you are correct till you get on a long decent then you will notice a difference. I have seen where high will slow me down to much and on low speed will creep up, I will then toggle between the two to maintain a speed range.
As mentioned before stock settings keep RPM's low on these things, down shift to higher RPM and they work well. That is true for any Jake on any engine. I do not normally down shift manually only on long down grades where is want Jake to work efficiently. Listen to any big rig, they always keep RPM up when on the Jake, Difference they have is a lot of gears to keep RPM's where they work best for the grade they are on.
My previous bus did the same as you described with an 8.3, that had an exhaust brake not a Jake as these do. But the second that was turned on tranny would down shift and keep the RPM's 1800 - 2200 these keep RPM much lower. 1800 - 1900 is very effective on these