Exhaust Brake

[BHiggins]

My '08 has the factory exhaust brake which works well, most of the time. It is, on occasion, inconsistent. Sometimes it's really strong in slowing the truck, yet other times it's considerably weaker, almost like it's not fully engaged. Also, sometimes it pulls well almost down to idle rpm's and sometimes it seems to shut off around 1600 rpm's. I've been told these "inconsistencies" have to do with the regeneration, and they're normal... I can't help but think that's not the case, and something else is causing it. Anyone have any similar experience? If so, what's the fix?

 

[jelag]

The factory exhaust brake needs to be used all the time... The brake changes the vanes in the turbo and move them from a forward position to a reverse position like the prop on a fan jet engine... . they reverse the prop to slow the plane...

Our trucks however build soot and if you leave the exhaust brake on all the time, the vanes stay free and move correctly across the spectrum from full boost to full retard or reverse... .

We have an 08 5500 with 110K miles, and we've not had a problem... we just leave it on all the time... .

Also, with the 6 speed its necessary to change gears... keeping the RPM between 1800-2400 will provide the most amount of back pressure and the best performance...

Hope this helps. .

 

[BHiggins]

That's the thing, I do leave it on all the time. The very first thing I do after starting the truck is push the button for the brake, and the only time it goes off is when I shut off the ignition. I also know they work best at higher rpm's. Even with those factors, it's still inconsistent. The truck only has 19k on it, and it's always been inconsistent. Sometimes it works well, and sometimes it doesn't. There's a very large hill near my house, if I go down it 10 times (at the same speed, in the same gear, with the same load) the brake will probably work well 6 or 7 times. The other 3 or 4 times it doesn't work AS WELL... It works, but just not as strong as it should be (and not as strong as the other 6 or 7 descents). And again keeping in mind that they work best at higher rpm's, sometimes the brake pulls just about down to idle rpm's, and sometimes it shuts off around 1600 rpm's. I just can't see this inconsistent behavior as being "normal".

 

[jelag]

Some of these trucks have had to have their turbos cleaned... . and the dealer than inserts a port in the housing so that can be done with chemicals down the road...

Our 08 is driven hard and we've not had a problem... If your still under warranty I'd ask. .

Our 08 is licensed for 19,500 lbs and often runs very close to that weight, remember its a 5500... and the brake is consistent...

 

[BHiggins]

When I bought the truck it only had 5k miles on it, and the brake has been like that since I've owned it. I understand what you're saying, but I just can't see the turbo clogging up in 5,000 miles. I was kind of hoping someone would have had the same issue and already addressed it.

 

[BHiggins]

I know it's been a while since I posted on this thread, but I have some new info in case anyone else was having the "inconsistent" problem with the exhaust brake... I went to the dealer last week for the J35 recall (flash/update software), and while I was there I told them about the brake problem. The service manager told me they could perform the recall work, but I would need to reschedule for any warranty work, as they were too busy. They installed the update, and since then the exhaust brake has performed flawlessly. I don't know for sure, but this is what I THINK was happening... The recall was because the computer was putting the truck into regen too often, which could lead to sooting of the turbo/exhaust components. I believe my intermittent brake problem was due to this flaw, in other words every time I had the problem, the truck was in "false" regen. It's been a week now, and the problem (which occurred several times a day) is completely gone. I just hope it stays gone.

 

[Prairie Dog]

Thanks for updating us Brian. All too often folks don't bother.

 

[AH64ID]

Glad its working for you.

I have wondered about the OEM exhaust back pressure sensor, are they clogging on anyone? I know my DP line will clog on occasion and needs a new line, and seems to happen faster when I use the EB to warm the truck.