CAT C9 ENGINE BRAKE

[LEAH DRAPER]

Well having the speed sensor replaced, after the software update has done nothing to enhance the engine brake, on my C9.  It is still at times remiss on engaging, if at all.  Some times after using the foot brake, it will engage, BUT it seems to me that, when the switch is turned on, that it should engage immediately.

I don't know if others with this engine are experiencing this issue or not.  Do I have a problem that need to be addressed by CAT?  Help please.

Leah

[LEAH DRAPER]

Another question related to my previous post..........

Is this a CAT issue or an ALLISON ISSUE?

[Mike Nunn]

The exhaust brake on my '07 Contessa will not engage, if it is in cruise control, and there is a delay on ours if the speed is over 65 mph.  I assume its just too fast to shift down to 2nd or 3rd gear. I just thought that was the way it worked.
Mike

[Gil_Johnson]

I think mine works as described by Mike--no engine brake with the cruise control on.  The engine brake on the 07+ engine will down shift 2 gears, not one.  Because of that I assume there's a maximum speed threshold that once you're going faster than that speed it will not respond.

BTW, who can reprogram the engine brake down shift from down shifting 2 gears to down shifting just one; CAT or Allison?  I know that was discussed here some time ago.  I need to get that done, I'm not a big fan of down shift two gears.

[LEAH DRAPER]

Am pretty sure that the re-programming is an Allison thing as I have talked with them about that.

What I was referring to in the previous post, about not engaging quickly or at all at times is when I am NOT in Cruise Control and I am city traffic probably not over 45 mph and the engine  is in 6/4 position.  

That's why I wanted to know if any one else is experiencing this as I described.  Am wanting to know if I have another problem here.