Seeking feedback, ideas,

 

To install an exhaust brake (EB) with a non stardard method to control the EB.

How?, leverage some functionality by adding micro switches, relay(s), tapping into the vehicle control modules.

This is not the preferred setup and will require the operator or system design to replace the functionality of an electronic control box.

 

Why? I have the brake itself, don’t have the expensive electronics.

Thanks in advance, First Post Ever,..

 

Application:

2002 Dodge Ram 5.9 H.O. Cummins, 6 Speed Manual Trans.

 

i figure a switch and string of micro switches that will turn the eb on/off could be used inline to the activation relay for the vacuum control valve.

 

Proposed Setup

 

Main Switch - 2 Speed Axel Switch on Transmission Shifter

pull to turn on,  provides a ground to a micro switch string, somewhere on the throttle and clutch.

 

The micro switch string will interrupt a Bosch relay, controls the vacuum solenoid for the EB.

when you push on the throttle or clutch, the vacuum solenoid for the EB will deactivate dumping the vacuum in the EB.

 

Ideas, thoughts, what would you do differently?

 

 

 

 

 

Edited October 12, 20186 yr by Hypertufa

Jacobs brake uses the feedback from the ECM. There is a pin in the ECM which is normally not used. This pin has delayed hit for the exhaust brake of about 2-3 seconds. Totally ECM controlled from the APPS sensor. Now other brands might not even use this method. No electronics or relays even used. 

 

The sad part is the Jacobs Brake is no longer produced the last that I know. Most people are going for PacBrake.  

didn't @Cowboy build his own EB?

I have a 4" BD Brake on my '99 5 speed.  It has the exact control set up you described with the exception of no relay.  All of the switches have plenty of current capacity to run the coil on the solenoid.  My setup did not come with a switch on the clutch.  What a PIA.  Very rough clutch engagement with the brake engaged.  I added a Micro Switch brand switch on the clutch and it works as well as I could ask for.

 

HTH,

Dan

Thank you Dan, nothin like talking to someone that’s been there, done that,..

Just FYI, I have ad EB on my 02 from Banks. It is all controlled with the hardware provided just like any EB you can find for an 02. I have a bit of a problem when I dont know year truck folks are speaking when it is listed in one post and not in their signature. Not trying to beat anyone over the head but the signatures sure help in providing good info. Had mine for about 7 years now.

Dripley,

 

i took you advise, added added a signature,

I thought the title of my post “Exhaust Brake Minimum Setup 2002 Cummins w/ Manual Trans” would speak to the application I inquired about.

 

IMHO, a signature may not speak directly to a certain post when the poster is a professional mechanic, helping a friend, seeking info about something that he does not own.

 

thank you for your observation.

5 hours ago, Hypertufa said:

Dripley,

 

i took you advise, added added a signature,

I thought the title of my post “Exhaust Brake Minimum Setup 2002 Cummins w/ Manual Trans” would speak to the application I inquired about.

 

IMHO, a signature may not speak directly to a certain post when the poster is a professional mechanic, helping a friend, seeking info about something that he does not own.

 

thank you for your observation.

I undersrand where you are coming. Should of soaked the title in a bit better. It is a bit frustrating and times not being to look below someones post and not being able to see what they are working with. By no means are you alone. We have a lot members with no signatures. Did not mean to pick on you alone.

 

 

I've seen setups like this... Personally, I don't have one. I'm not particularly impressed with it. Manual exhaust brake controls can be done but you have to instruct all people using the truck to make sure to not have the exhaust brake on while attempting to throttle this will for sure do engine damage as the EGT's will skyrocket.

 

The only reason I know this is years ago I call a warranty claim on my exhaust brake the vacuum valve was sticking on and if the exhaust brake was applied yet as you throttled it would skyrocket the EGT's. I had to unplug the vacuum to disable the exhaust brake because of a faulty vacuum valve. 

 

 

2 hours ago, Mopar1973Man said:

I've seen setups like this... Personally, I don't have one. I'm not particularly impressed with it. Manual exhaust brake controls can be done but you have to instruct all people using the truck to make sure to not have the exhaust brake on while attempting to throttle this will for sure do engine damage as the EGT's will skyrocket.

 

The only reason I know this is years ago I call a warranty claim on my exhaust brake the vacuum valve was sticking on and if the exhaust brake was applied yet as you throttled it would skyrocket the EGT's. I had to unplug the vacuum to disable the exhaust brake because of a faulty vacuum valve. 

 

 

I am not familiar with an ECM controlled exhaust brake.  What feedback would your ECM receive if your solenoid valve stuck?  I'm assuming it is an open loop control circuit and the ECM wouldn't know if it stuck.  

Curious,

Dan

1 hour ago, roadwarrior said:

What feedback would your ECM receive if your solenoid valve stuck?

 

None. It would force itself down the highway till it burned up.

 

1 hour ago, roadwarrior said:

I'm assuming it is an open loop control circuit and the ECM wouldn't know if it stuck.

 

Correct. Even the newer 6.7L truck with a VGT turbo will do the same thing. They don't detect high driver pressure. 

 

Mine was set up with one wire on the PCM, ECT, and TPS. Cold start it stayed engaged until 140*. I think, correct me if I am wrong, the PCM sent a speed signal to the EB's brain so it could shut off at 15 mph and reengage at 35mph providing the TPS showed 0% throttle. There is also a 1.5 to 2 second delay in it engaging. Their is also a wire that connected, where I am not sure, for the cruise control that would not let it engage while cruise was turned. My cruise was not working at the time so I did not connect it. After getting cruise fixed it would engae while cruising and the egt's would go from 600* to 1300* very quickly.

I know this doesnt pertain to 2nd gens but my dad had an 06 that he added an EB to and it definitely functioned with the pcm. You switch it on and air pressure kept the butterfly closed not vacuum. If you hit the throttle it deactivated but would come back on if you let off, it would disengage temporarily during shifts too if I remember right (auto trans), it was pretty trick. I cant remember who the manufacturer was anymore.

 

A side note, for manual transmissions you can also use the EB on an incline. Example- Hauling something super heavy and you cant gain much if any speed because you had to come to a stop or slow down for whatever reason so you need to shift as fast as you can to make up for the inablility to increase speed and your limited by having to shift gears.

Turn on the EB and let it reduce engine speed faster so that you can shift faster while you have the clutch pressed in. Heavy truck guys already probably know this but its something my dad used to do when hauling stuff around town in his heavy trucks. Hopefully that makes sense its not a complicated process but i think i might have made it sound that way. But you HAVE to have an EB that disengages when you touch the throttle or it wont work.

I still think exhaust brake system that uses a flap in down pipe contributes to valve guide wear. You're forcing all that carbon through guides passed valve seals and into valve cover space. Slowly it wears bigger gap allowing for more carbon build up that makes for sticking valves and creating heat and farther wearing guides and valves. And that carbon is hard stuff. I guess if you can go 300-400k on a head using EB then who cares, rebuilt it and do it again. 

Idk  jmo.

Slowly being a operative word... I've often thought all that back pressure hitting all at once is not good.  A better system imo would be for back pressure to be applied sequentially over maybe 3-5 seconds...insteading of slamming all at once.  Dont know how to make that happen though.

11 hours ago, Mopar1973Man said:

Manual exhaust brake controls can be done but you have to instruct all people using the truck to make sure to not have the exhaust brake on while attempting to throttle this will for sure do engine damage as the EGT's will skyrocket.

 

I don't have a throttle switch or clutch switch with my exhaust brake setup and I use a momentary foot switch on the floor below the clutch pedal to operate the exhaust brake.  I agree that you shouldn't use the exhaust brake and throttle at the same time, but for a different reason - that reason being that it would be possible to float the exhaust valves resulting in engine damage.  

 

How would EGT's "skyrocket" if you throttled while using the exhaust brake?  I am not saying that it didn't happen to you - I am just trying to understand.

 

In my thinking, the maximum air flow through the engine could only be what could pass through the orifice in the exhaust brake valve while it was closed.  The turbocharger would not be able to spool up because the drive pressure on both sides of the turbine wheel would be virtually the same pressure.  So in essence, the engine would be performing as a naturally aspirated engine with a severely restricted air flow.

 

To support my theory, I took my truck for a test drive and attempted to accelerate with the exhaust brake actuated in fifth gear.  Engine rpms peaked and stabilized at about 1700 rpm, boost remained at zero psi, and the EGT's peaked and stabilized at 800 degrees, and lots of black smoke poured out of the exhaust pipe.  The zero psi boost, the 800 degree EGT, and the black smoke were about what I expected to see since there was not nearly enough air to burn the fuel to generate power or heat.

 

- John

 

Based upon input from the contributors 

i am guided to letting pin 20 ECU 50 Pin Connector provide 12+ as the control circuit for the 12v vacuum solenoid, scraping the idea of micro switches.

this does not allow for the exhaust brake to be used to slow the engine down for quick shifting as 12v+ is supplied after the engine has been defueled for 1.5 sec.

 

hmmm,, now to figure out how to gradually engage the brake, or does it work that way as the vacuum module has to have vacuum applied to overcome spring pressure?

Side note—

Engine brakes are now being offered for common rail and newer Cummins 

https://pacbrake.com/product-lines/loadleash-engine-brake/

Edited October 30, 20186 yr by Hypertufa
Spelling

Didn't know Adam Sandler was into this sort of the stuff

 

I wish we could put a system like that on our trucks! (2nd gen) 

The only damage ive personally seen from engine braking was an employee of my dads engaged the brake from high rpm with a huge load and it sucked a valve chewed up the turbo destroyed the cylinders. Needed an in frame after that. I dont believe that was an exhaust brake though im almost positive that one had cylinder deactivation. Ive never heard of any failures resulting from exhaust brakes. Even the mopar accessory exhaust brake kit the only thing that i've ever seen happen was the belts get chewed up once in a while and they are a nightmare to find a replacement for when your dealing over the phone with parts stores sending samples and all that