Engine/Transmission (1998.5 - 2002) Jake Brake Question

[SWC]

Not to hyjack this thread, but for those dealing with the APPS issue here is how I got around that problem.

I had the issue where the APPS would not send a closed throttle signal to the ECM and as a result the Pacbrake would not engage. In my case it only occured when I used the cruise. The engine would idle only slightly higher then normal so I could live with this as I no longer had warranty.

To get around the ECM and still be able to use my Pacbrake I ran a fused 12v to an on-off-on switch. I use this switch in reverse with one side from the ecm and the other side from the 12v source. I have instant exhaust brake without the ECM delay when I pull the switch on the gear shifter. I put the switch into the ecm position if someone else drives the truck so they don't accidently turn the exhaust brake on when they are on the throttle.

My APPS finally got so bad 1 year ago I replaced it with a Dodge unit. Why didn't I use the Timbo unit you ask? At the time Gary, Timbo and others were expermenting but did not have anything working.

I still bypass the ECM because I like the instant activation of the exhaust brake.

Stan

 

[cap-n-cray]

Benhall,



I have the exact same problem. The exhaust brake fails to work only during a long trip mainly when I use the cruise control, but not all the time. I was moving from Southern Cal to Washington towing an enclosed trailer. I needed the brake for some of the passes. The only way I could get it to work after many hours of driving was to pull off in the brake test area and shut down, wait a few minutes, start up again and the brake would work for another couple of hours.



I did notice that the truck would not return to idle when the exhaust brake failed to work. It would also idle above 1K. I took it to my dealer in Southern Cal and they wanted to see it when it happened. Of course it was hard to do. Finally it happened on a trip and I was near a dealer in Oregon. They said it was the APPS and wrote up a report. I took that report to my So Cal dealer and they would not accept it. Finally it happened near my So Cal dealer, they said it was the VP pump. Of course I thought it was the APPS, but if they wanted to replace my VP pump (Just over 100K) under warranty I chose not to complain.



Of course the new VP pump did not cure the problem. It happened again on the next trip. I now carry a new APPS with me on trips. Since it only happens on long trips I don't notice it much. I do use my exhaust brake every day. I have noticed that sometimes I get a slight surge at steady speed. One of these days I will replace the APPS.



Cary

 

[benhall]

Thanks for the input! It happened pretty much the entire way back down here to Florida, except for one leg of my drive when it worked like it was supposed to. I think I'm going to replace the APPS next weekend when I have more time and to figure out how to read an electrical meter. :-laf



Ben

 

[JHoogland]

My truck does same thing but only half the year living in az in summer never happens i noticed below about 54'f is when the jake brake stops working when cruise is turn off (rpm raise to about 1000 for idle )i will replace apps soon so hope this is it been doing it about 3 years now. Was able to live with it druing winter. But its time to fix. New apps is on order from genos.

 

[dresslered]

Wow even on a 6Spd truck you still have to use the ECM? My BD is straight up on a micro switch under the pedal so when you are off throtle I simply flip the pedal up. ( I set it that way)

TMTT, PC12Driver has it correct. The ECM just gives you the delay (if you want) so that you can shift between gears without the e-brake coming on. Nothing that has to be used although I like it on mine. I use a shifter mounted switch to turn it on/off at lights.

 

[BrettMiller]

I'm having an issue with my Jake Brake not working after long periods of driving with the cruise on and at interstate speeds. Is there something in the ECM that is telling the actuator not to work? It will start working again after I shut the truck down for 5 min. , so I'm not sure what's going on here.

Ben

Ben, i am having the same trouble with my pac brake on my 01 and it is bone stock when it quits going down the highway if i shut it off for 5 or 10 seconds and start it back up it works fine and now i see its supposedly the apps sensor how much does one of them cost?

 

[benhall]

I put the APPS sensor on that is described in this thread: https://www.turbodieselregister.com...n-1998-5-2002/198522-anatomy-apps-sequel.html, and haven't had an issue since.



Ben

 

[Silver Ratler]

Everytime I see someone post something about a "jake brake" and our CTD pickups I get soo excited..... eveytime after reading I find they really mean exhaust brake..... Boy would I love to have a Jake brake on my CTD for towing my fiver... . guess I'll just have to buy me a "big" truck to get one.