Jump to content

Internal Jake Brake not working


Recommended Posts

Sorry for the long explantion.We have a 2004 Monaco Dynasty with a Cummins 400 ISL. Our internal Jake brake has a high/low switch in the panel to the left of the drivers chair and a foot switch that is pressed and held to activate the jake brake.

Our jake brake stopped working entirely. When the foot switch was pressed, the transmission would preselect second gear and start to downshift but the Jake would not activate.

We had a remote diesel mechanic come out to diagnose it. While connected to the ECM with Cummins INSITE, per instructions from Cummins support he modified the value of  "engine brake type" from "undefined" to "exhaust engine brake". After making that change, the transmission no longer preselects second nor attempts to downshift. 

While trying to change the value   "engine brake type" back to "undefined" that value no longer exists in the drop down options for "engine brake type". 

We were the told by cummins support that "undefined" is an OEM option and we need to get the ECM template from Monaco so it can be restored.

Since the switch wont activate until the "undefined" value is restored with are dead in the water to continue diagnosing the jake issue.

Thanks to anyone who knows where we can get the template?

Edited by bmulvenna@hotmail.com
Link to comment
Share on other sites

Shouldn't he just reload the original image saved before any changes were made? I would think he had it saved. There's your template.

BTW, changing parameters to fix something that used to work makes no sense to me, they don't just change by themselves.

Edited by Ivan K
  • Like 1
Link to comment
Share on other sites

There was a recent post in July by @hweyrich@wowway.com who was looking for an image and I think he got it from Five-Star Freightliner in Dothan, AL.

Maybe he will chime in or you could contact him. Sorry about your trouble.

Link to comment
Share on other sites

Do you have an exhaust brake or an engine brake?  My 2004 Signature has an engine brake but no exhaust brake, also with a foot pedal.   Detroit 60 w Cummins 4000. 

Link to comment
Share on other sites

I am certainly no expert on Jake Brake, but I have repaired ONE.  It was on a 2004 Dynasty or Sig (I think).  When looking at the engine with the rear engine hatch open, there is an electrical connector plugged into the left side of the valve cover.  I removed that connector, flushed both the plug and socket with a stream of WD-40 and reconnected it.  The Jake Brake started working again.  That was a couple of years ago, and it is still working.  Hope your problem is that simple.

  • Like 1
Link to comment
Share on other sites

2 hours ago, vanwill52 said:

I am certainly no expert on Jake Brake, but I have repaired ONE.  It was on a 2004 Dynasty or Sig (I think).  When looking at the engine with the rear engine hatch open, there is an electrical connector plugged into the left side of the valve cover.  I removed that connector, flushed both the plug and socket with a stream of WD-40 and reconnected it.  The Jake Brake started working again.  That was a couple of years ago, and it is still working.  Hope your problem is that simple.

Thanks I will give that a try. Still have to restore thf ECM image however.

19 hours ago, Dr4Film said:

Where are you now??

Still in Show Low. Will try to get appointment in Provo area.

Link to comment
Share on other sites

  • 1 month later...

We also had a problem with our Jake Brake failing.  First it was an intermittent issue, then this spring it failed completely.  At first I thought it might be the 87 relay which is located in the FRP so we changed that.  No luck.  Then I removed the foot pedal and did a continuity test.  With the switch held down in the closed position the resistance was about 5000 ohms instead of nearly 0.  We had our local truck center track down a replacement switch which I also tested before installing and sure enough the resistance was about 3 ohms.  We installed the new switch and our Jake brake has been working perfectly since.  These switches are designed to last a long time but they obviously can still quit.

Link to comment
Share on other sites

On 10/8/2020 at 5:20 AM, Bruce S said:

We also had a problem with our Jake Brake failing.  First it was an intermittent issue, then this spring it failed completely.  At first I thought it might be the 87 relay which is located in the FRP so we changed that.  No luck.  Then I removed the foot pedal and did a continuity test.  With the switch held down in the closed position the resistance was about 5000 ohms instead of nearly 0.  We had our local truck center track down a replacement switch which I also tested before installing and sure enough the resistance was about 3 ohms.  We installed the new switch and our Jake brake has been working perfectly since.  These switches are designed to last a long time but they obviously can still quit.

Did pretty much the same. Switches all good. Found a  blown fuse and all is at better.

Edited by bmulvenna@hotmail.com
Link to comment
Share on other sites

  • 1 year later...

Finally found the problem with the internal Jake. Three Cummins experts in Phoenix have looked at it unsuccessfully. One even gave us a $6500 estimate to rebuild the internal 2 stage Jake. The other 2 just threw up their hands and told us the Jake is working the way it is designed.

I finally decided to spend some time cleaning the 2004 cummins isl 400. 

While doing so I discovered a wire buried under other parts that was not connected to anything. I found a connection in the side of valve cover that looked like it was the place to connect the wire to. 

Connected it then drove to and returned from Sunset Point on the way to Flagstaff from Phoenix. It has a 7 mile 5 and 6 percent downgrade. The jake worked perfectly holding the coach at 45 mph down the entire 7 miles. The connected wire now allows the solenoids to activate the jake allowing it to work the way it should.

At 74 I should have known to dig into this myself earlier.

So much for the $170 per hour experts.

 

 

  • Like 2
Link to comment
Share on other sites

Richard, so often that is true.  A mechanically inlclined DIY person with a "can do" attitiude" can so often far outdistance the capabilities of a "professional" That one has to wonder where they got the title "professional".

If you have even an ounce of mechanicial aptititude, always exhaust the the online resources before even THININGK of going to a "Cummins Coach Care" PROFESSIONAL. 
 

Link to comment
Share on other sites

In fairness to those few truly competent and professional diagnosticians at Cummins service facilities, the great majority of them seem to be recruited from "Jiffy Lube", and don't know their butts from a hole in the ground.  Bring them a Cummins-powered Peterbilt with fuel system problems, and they MAY be able to make an intelligent diagnosis.  But a "MOTOR HOME"?__ONE  OF THOSE PEOPLE who cannot even adequately describe in detail what the symptoms are?  But most of the time, they are "parts replacers" until they stumble upon the problem.

If you are a MH owner with no resources other than a credit card, you are going to be disappointed...and about to get an anal reaming.  Despite all the hoopla, Cummins facilities are suffering the same lack of "people wanting to work for a living" as the rest of the country.  Professionals who take pride in their diagnostic abilities are becoming more and more rare...AND OPENING THEIR OWN SHOPS, after feeling embarrassed at the incompetence of their fellow mechanics.

Moral of the lesson:  Use spectacularly talented online people to help you at least understand what YOUR problem REALLY is, before you put yourself at the mercy of some fellow whose main talent last week, might have been, "Do you want fries with that?".

  • Like 3
  • Haha 2
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...