Automatic transmission with Jake's going down the hill

I have to use my brakes all the time with my engine brake. With a full load going down a steep hill I’ve never had a truck that the jake would totally hold it. I’ve always thought of jakes as a supplement.

 

If I just go down a hill and trust my engine brake to hold me, if the hill is steep enough, it will over rev the engine and start beeping at me to reduce engine RPMs. AKA hit the brake pedal.

 

What are you building for boost on each stage? Should be a difference between the stages, especially from stage 2 to stage 3.

 

The only thing that makes sense is that your are on stage 1 of the Jakes instead of stage 3. Stage three will snap your head forward.

 

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I'm guessing you were heavy, maybe front loaded if you're in a dry van or reefer. If that's the case, at 20mph, you'll need to stab break periodically. Also, if the recommended speed for descent is 20 mph, that's assuming you're empty. If fully and heavily loaded, at that down grade perentage, you needed to be closer to 10 mph for that jake to hold.

 

Yeah something isnt right there

I can bomb down 6-8% with my X15 in 7th direct with 3.70 rears (18 sp) at 50 mph with 60k lbs on and not touch the brakes

I bet its in the programming.