Do you brake lights come on with the engine brake?

[Mr_D]

I had our 2000 DSDP/FL CAT 3126 reprogrammed to preselect 4th when the ebrake is active. Forever wished I hadn't had it changed from the factory preselect of 2nd. Traded the rig off before I had it changed back.

[AFChap]

What happens is the engine brake will engage (if it's turned on) when cruise speed exceeds the 5 or 7 mph over the cruise set speed. The transmission will downshift in time, as speed builds, with the engine brake engaged, thus slowing the coach in this situation.

So yes, I do use cruise in the mountains on my diesel coach. If it doesn't react quick enough, I turn the cruise off, which engages my engine brake immediately and shifts to 4th (Latch Mode). I find the Allison extremely intelligent and drivable in most all conditions.

Exactly so ...and I KNOW that my brake lights do not come on when the exhaust brake kicks in when cruise is engaged. When cruise is not on, the exhaust brake activates 3 brake lights on the MH and 2 on the toad. If/when I apply the foot brake firmly enough to activate the toad brakes the toad brake light comes on indicating to anyone behind that more braking is applied. (Actually the auxiliary toad brake activates additional bulbs in the toad brake light fixtures too but most folks probably would not notice those two.)

[FIRE UP]

Originally Posted by Pusherman

Scott,
Our Allison transmissions and CAT C7's are capable of slowing the coach while in cruise. There is a parameter programmed into the ECM which will activate the exhaust brake while in cruise to a preset over MPH situation. I think factory default is 7mph over the cruise set speed.

I had mine reprogrammed to engage at 5mph over the set cruise speed.

What happens is the engine brake will engage (if it's turned on) when cruise speed exceeds the 5 or 7 mph over the cruise set speed. The transmission will downshift in time, as speed builds, with the engine brake engaged, thus slowing the coach in this situation.

So yes, I do use cruise in the mountains on my diesel coach. If it doesn't react quick enough, I turn the cruise off, which engages my engine brake immediately and shifts to 4th (Latch Mode). I find the Allison extremely intelligent and drivable in most all conditions.

Don,
I kind-a figured it operated that way. I'm always trying to learn about the big gymnasium on wheels. As stated, my E/B switch is never turned off unless I'm in city type driving or, I DO WANT TO COAST at a bit higher speed for various reasons. But, your explanation pretty much verifies my suspicions of how the system works. One of these days we'll get to a camp Freightliner and really dig into some things like this. Thanks a heap.
Scott

[Ray,IN]

This Allison Transmission pdf,says the grade retard feature is an option available for a standard Allison transmission.