Exhaust Brake Acting Up

[dragon_ram]

Knowing the difference between “auto” and “full” for the diesel exhaust brake, is it normal for it to NOT engage when braking? I noticed between 25-30 MPH it would sometimes quit or not initiate, even though I was still braking (8% descent). I also noticed it wouldn’t engage randomly at higher speeds (45+ MPH) but if I hit the gas briefly (can you still say that in a diesel?) it would THEN engage once lifting the foot off...

My first diesel... normal behavior?

 

[Bozo]

Knowing the difference between “auto” and “full” for the diesel exhaust brake, is it normal for it to NOT engage when braking? I noticed between 25-30 MPH it would sometimes quit or not initiate, even though I was still braking (8% descent). I also noticed it wouldn’t engage randomly at higher speeds (45+ MPH) but if I hit the gas briefly (can you still say that in a diesel?) it would THEN engage once lifting the foot off...

My first diesel... normal behavior?

That sounds normal. It is affected by your level of braking pressure and works better in tow/haul mode. Takes a little practice to get used to.
It gets more aggressive with a load and your brake foot.

 

[Deleted member 80]

Also, it cuts off based on RPM, in the 800-1000 range I'd say, so if you are not in Tow/Haul, it's pretty easy to be rolling along at a pretty good clip and have no ex brake. Press the T/H button, and it will wake up.

 

[MikeXM]

Also, it cuts off based on RPM, in the 800-1000 range I'd say, so if you are not in Tow/Haul, it's pretty easy to be rolling along at a pretty good clip and have no ex brake. Press the T/H button, and it will wake up.

THIS. When RPM is below 1000, EB will not engage to not choke the motor. Check RPM when you feel like it should have engaged and it did not.
When Tow/Haul mode is ON, transmission will downshift when you slow down, so it will bring RPM up and therefore EB will engage.

 

[BULLSANDBUCKSHUNTER]

Anyone figure how to get brake to come on everytime you start truck? I always forget till i am miles into trip.

 

[dragon_ram]

Just to clarify, this was all whilst in Tow/Haul and with a 10k lbs trailer attached.

 

[Deleted member 80]

Just to clarify, this was all whilst in Tow/Haul and with a 10k lbs trailer attached.

Likely not normal, then. Maybe an actuator issue?

 

[Brutal_HO]

Anyone figure how to get brake to come on everytime you start truck? I always forget till i am miles into trip.

Nothing to be found in AlfaOBD,

Need to simulate a trailer brake connection. 12 Ohm 10W resistor from brake-ground on a 7-pin plug adapter and set the gain to 0. I used a 7 to 6 pin adapter that I never use for anything else.

I suppose one could get creative and setup one of the Aux switches to connect the trailer brake circuit to a load through ground and set the switch to be sticky (last set). I assume the circuit would need to have a diode in it to prevent issues when a trailer is actually connected. So to prevent all the, the dummy plug is just easier and more KISS.

 

[Epsilon Plus]

People say to have it all the time to keep the ring moving...etc.

I'm starting to wonder how this affects the 68RFE though. I thought I read somewhere that the early exhaust brakes were hard on the thrust bearing or output shaft bearing. In my truck, I can feel the surges with it in auto unloaded and slight bucking with it working. I like the braking performance and keeping the turbo moving but wonder if the trans is getting the short end of the stick with this logic.

 

[Brutal_HO]

I've decided that being unable to engage the rear park sense with a trailer sim plug isn't worth it. I'll just keep pressing the button when I fire it up.

 

[CanadianIronhead]

Maybe your TC was unlocked and the transmission coasting? If so your EB will not kick on, at least that's what happens with my truck.
Little blip in the throttle and voila TC locked up and EB on.