HELP-Exhaust brake warmup malfunction

[kkriz]

A friend of mine at work just bought a 2003 3500 with the HO motor and had the dealer install a Jacob's exhaust brake. He has used the warmup feature only to discover that the brake doesn't open at 170-175F like the manual says it is supposed to potentially causing overheating. When he took it back to the dealer they called the Star help line and was told that the automatic shutoff feature is not part of the ECM program any longer. Has anyone else had this problem?

 

[ntenna]

I left mine (Jacobs) on at idle on a recent 65 degree day to see what would happen. Nothing did. Temp stayed at 190. And that was with awinter front on the truck!

After 10 minutes I was ready to go, so no more test.

And on the earlier post wondering if the trucks ran hotter in general would be a problem... well, no difference with the winter front pulling either. Still stayed at 190 on a 65 degree day.

Perhaps the 5/8" hole in the butterfly means no need to shut it off at hot idle?

 

[MMeier]

How the heck do you overheat an idling Cummins?? Come on people where's your common sense?

 

[Dean Upson]

My 98. 5 never came near to overheating at idle with the brake on. I doubt the '03 would overheat if you idled it all day with the brake on even without the temperature shut off.



Dean

 

[Briman]

I installed my Jacobs brake today. The hole in the flapper is 1/4 inch, 5/16 max, not 5/8". I left the brake on for 15 minutes at idle and the temp gage didn't budge from 140. This is the same as my Y2K with Jakeobs brake. I don't think you can ever warm up a cold Cummins by idling.

 

[ntenna]

Oops. Sorry, typo. Meant 5/16"... ... anyway, everybody is correct here. The Cummins can idle just about forever blocked and not over-heat... ...

 

[Carlton Bale]

Here's the deal:



MY2003 engines: Brake will shut off at idle when coolant temperature reaches 220 degrees F.



MY2003. 5 engines: Brake will shut off at idle when coolant temperature reaches 175 degrees F.



MY2003 owners do not have to worry about this feature overheating their engines. First of all, the engine temp will probably never reach 220, just as it was with the MY98. 5 engines. Secondly, if it does reach the shut-off temperature, 220 at idle is not a concern but higher than that would be.



Sorry for the confusion. We're revising the brake manual.

 

[ntenna]

Thanks, Carlton. Appreciate you keeping us up-to-date here.

 

[yogibear]

Carlton, is there any way to defeat the 2 second delay? I really don't like it, I drove the ones with the micro sw. under the foot pedal too long. Thanks,



Larry

 

[Carlton Bale]

Originally posted by yogibear

Carlton, is there any way to defeat the 2 second delay? I really don't like it, I drove the ones with the micro sw. under the foot pedal too long.

Unfortunately, there is no way to change this characteristic. The delay time is set in the Engine Control Module and cannot be adjusted.



If you wanted to give-up ECM control of the brake, you could go back to a micro-switch. You would manually send the 12V signal to the brake actuator in this case. Please note, Cummins does not recommend or warranty this type of configuration. I saw another thread discussing this. Other than that, there really aren't any options.

 

[yogibear]

OK, Thanks very much for your quick reply, I really appreciate that.



Larry