Exhaust Brake ?s

[HBellmyer]

Installed a Pacbrake last Friday. The system works well except for not dis-engaging immediately at idle. When I come to a full stop it stays on for around 5 to10 seconds. When I was finally able to reach someone at Pacbrake I was immediately told that my ECM needs to be re-flashed. I do not like to mess with things that are not broke. Has anyone had this problem and if so what was the fix?

 

[isb360]

A friend of mine is a truck driver whose boss has about 50 Kenworths with the 8. 3L CTD and Pacbrakes. He tells me that almost all of them have very similar problems to yours. The Kenworth dealer that sold them says that many people are having the same problems and no body has figured out how to fix them permanently. I wouldn't flash the ecm just because Pacbrake says so. Sounds like they're shifting the burden of blame. He has a Jacobs exhaust brake on his 01 3500 and loves it. It was a dealer installed option when he bought it new and hasn't had a lick of trouble with it ever since. See if you can get a Jacobs and send the Pac back!

 

[Cummins724]

My brother had the same problem with his Pacbrake on a 98. 5. I disconnected the wire that goes into the ecm & hooked it through a pedal switch. I bought the Pacbrake pedal switch from Advanced Diesel Technology 304-864-3399. I have the same switch on my truck & it is super fast engage/disengage... . you'll love it.

 

[Cummins724]

A friend of mine is a truck driver whose boss has about 50 Kenworths with the 8. 3L CTD and Pacbrakes. He tells me that almost all of them have very similar problems to yours. The Kenworth dealer that sold them says that many people are having the same problems and no body has figured out how to fix them permanently. I wouldn't flash the ecm just because Pacbrake says so. Sounds like they're shifting the burden of blame. He has a Jacobs exhaust brake on his 01 3500 and loves it. It was a dealer installed option when he bought it new and hasn't had a lick of trouble with it ever since. See if you can get a Jacobs and send the Pac back!

My brothers Pacbrake has more holding power than my Jacobs & my other brothers Jacobs. The Pacbrakes don't have the "hole" in the butterfly valve like the Jacobs & this gives it more holding power. Just do the throttle pedal switch & be done with it.

 

[TAbbott]

They'll stay engaged indefinitely if the coolant temp isn't up to 190 degrees. That's how the quick warmup feature works on a cold morning. I had that same "problem" with my PRXB, and cured it by installing a clutch switch. The way it's set, just barely touch the clutch and the PacBrake switches off instantly. Works great.

 

[pgleavitt]

Same here with the pedal switch and no ECM hookup. Instant on and off. No lag and I use it every day in normal driving. The only problem I have had was when I washed my engine compartment and had to take the vacuum switch apart and clean it. I have the shifter mounted switch.

 

[seafish]

I am thinking seriously about installing a PXRB on my 2005 with G56. I was unaware of any ECM control issues with the PXRB until I came across this forum. I certainly wouldn't mind using a manual switch to control the exhaust brake if it works better than the ECM control, but I am confused by all of the different switches mentioned here-- throttle switch, clutch switch, pedal switch, shifter switch? Which works best and installs cleanest? Also wondering about any other trouble issues with the PXRB system in terms of reliability and longevity? TIA

 

[wcjp]

I ran mine through the ECM. No problems. It disengages within one second of a complete stop. Will stay on if engine is still cold. I added the optional switch for the shifter (G56). Can't believe I never added an Ebrake to my 96'.



There are optional switches that can be added. I might add a switch to the clutch pedal. Throttle switch isn't necessary if connected through the ECM. The optional switches open the circuit disabling the Ebrake.

 

[seafish]

Thanks wcjp! So let me get this straight... the shifter switch is a sort of manual on/off for the whole set-up and the pedal switches are temporary overrides for the PXRB ?And now,of course, I have even more questions-- Does the shifter switch turn the compressor on and off or just the PRXB piston? Also, what kind of switch on the shifter and how neatly does it wire in ( I wish Genos would sell a knob switch for the G56 like they do for the nv5600!!) Why do you want to add the clutch pedal switch? Also, do the pedal switches wire to the ECM or the PXRB or both?? Does PacBrake sell the pedal switches with install instructions, or are they simply generic items? Also wondering if one does NOT hook up the PXRB through the ECM, does a throttle switch then become necessary?? Sorry for all the additional questions-- TIA again!!!

 

[Cummins724]

Thanks wcjp! So let me get this straight... the shifter switch is a sort of manual on/off for the whole set-up and the pedal switches are temporary overrides for the PXRB ?And now,of course, I have even more questions-- Does the shifter switch turn the compressor on and off or just the PRXB piston? Also, what kind of switch on the shifter and how neatly does it wire in ( I wish Genos would sell a knob switch for the G56 like they do for the nv5600!!) Why do you want to add the clutch pedal switch? Also, do the pedal switches wire to the ECM or the PXRB or both?? Does PacBrake sell the pedal switches with install instructions, or are they simply generic items? Also wondering if one does NOT hook up the PXRB through the ECM, does a throttle switch then become necessary?? Sorry for all the additional questions-- TIA again!!!

You have the first part right. The shifter switch [stalk switch] is a on/off switch for the exhaust brake system. The pedal switches are a activation switch which tell the vacuum/air solenoid to open/close. You can buy the stalk switch directly from Pacbrake, but I just like the Jacobs switch better... . looks like a 2 speed axle switch. You can download directions for install on their websites.

 

[Pacbrake]

We have found that some NOT ALL ECM's do not turn the ground activation off all the time. The best way to check this is put a test light on the wire coming from the ecm to the compressor when this happens if it is not cutting the signal then its an ECM issue and it will need to be reflashed.

 

[Pacbrake]

A friend of mine is a truck driver whose boss has about 50 Kenworths with the 8. 3L CTD and Pacbrakes. He tells me that almost all of them have very similar problems to yours. The Kenworth dealer that sold them says that many people are having the same problems and no body has figured out how to fix them permanently. I wouldn't flash the ecm just because Pacbrake says so. Sounds like they're shifting the burden of blame. He has a Jacobs exhaust brake on his 01 3500 and loves it. It was a dealer installed option when he bought it new and hasn't had a lick of trouble with it ever since. See if you can get a Jacobs and send the Pac back!

I've been doing the warranty and Tech for Pacbrake for 10yrs and have never received a call from anyone in CT with 50 KW trucks having a Pacbrake issue. If this is true please give them my number 1-800-663-0096. I would love to find out whats going on and fix them correctly. Pacbrake has always stood up for its product and customers, if we have a problem lets fix it. .