CoastalDav

I said I'd never install one of these brakes on my truck because of the Vacuum Pump failures. Well, I did install one. When installed you could not hear it engage with the engine temp below 170 at idle. The installer pulled the pin on the adjustment arm and turned it in 3 turns and replaced the pin. It was audible at that setting. I had to go to the Dodge Dealer to reprogram the computer so it would work properly. It does work good, but, does not hold as good as the one I had in my 2000 Dodge.

Does anyone have any info on how many turns and in what direction from a given point, it needs to be? or

EDIT; Count the number of threads from the vacuum can to the lock nut on the hyman joint arm that actuates the lever that closes the disc in the exhaust elbow.

I have called, written, e-mailed, both Jacobs and Cummins with no responses.
Figures.

Thanks in advance.

Dave

bigfoot

Can’t help you but I’m going follow this closely. I have a 09 that the Jake does not work nearly as well as the one on my 02.

KATOOM

A Jake Brake is an engine brake. What you have is a Jacobs exhaust brake. Did you purchase the EB new or used? You definitely know when its engaged. There's nothing quiet about it and you should easily see the EB move. I'm not sure what anyone was thinking to change the adjustment arm? Thats not adjustable for the consumer but for when the EB is being put together. That adjustment allows the butterfly valve to be set at precisely the right degree of angle of whatever Jacobs requires. So now that you have no idea what it will take to put it exactly back, you may have to get ahold of Jacobs and ask them for help resetting the butterfly valve. Hopefully it can be reset without needing to send it back. Matter of fact, the first thing your installer should have done was call Jacobs when it didn't seem like it was working properly. Cummins will have nothing to do with whats going on.

J&L

Your '09 doesn't have a Jake. The 6.7 engine uses the Holset turbo VGT with a sliding nozzle that works as a exhaust brake.

Some mfg won't answer a email very quick so I do the 1-800 number.

CoastalDav

Yep, its a Jacobs exhaust brake. It was purchased new. Did you read what I wrote? Yep, when working properly, you know when its engaged. My last truck had one. Did 203,000 miles with it, so I know how its supposed to work. The adjustment was changed as stated previous, because the arm did not move far enough to hear it engage when the engine was cold at idle, which it is supposed to do up to 170 degrees. Apparently it came from the factory that way. There is a hymen joint with a lock nut on it which is threaded down from the vacuum can. Yep, it would be nice to know what the precise angle is supposed to be It did not work at the factory setting!

I have contact Jacobs and Cummins numerous times via phone and e-mail. No responses. Matter a fact the first thing the installer did was to contact both Jacobs and Cummins with the same result I got. If I put it back, and I know which way and how many turns, it will not work. Its a Cummins Part, bought from Cummins. The local Cummins shops don't really care about it as no one I've talked to in parts can even find one in the system. Cummins in Tampa told me they don't make them anymore?? I don't know if I belive that or not.

So I'll wait around until either someone knows something or put up with what I have. EGT's are normal, so the disc is not to far at this point. I may give it another turn on the arm adjustment.

KATOOM

I thought we were talking about an '06?

CoastalDav

Yep the truck with the problem is a 2006. The one I drove previous was a 2000 with Jacobs EB.

KATOOM

Sure did read what you wrote.....which is why I asked what I did, otherwise I wouldn't have.

So back to trying to help you.....I do know that some 3rd gen EB's have a "warm up" feature controlled by the ECM where by the EB only partially closes until a set engine temp of something like 170-180* and then after full engine warm up the EB works like normal. Maybe thats what you were unknowingly facing and because Jacobs costumer service is apparently less than desirable, you (or your installer) messed with it trying to solve what was already working properly. Again, Cummins wont have anything to tell you, even though its a Cummins part number. Jacobs is just affiliated with Cummins and sells their product through Cummins and Dodge.

bigfoot

So could you say that in English?

I think I’m reading what you said to mean that what I have is what I get and that there is nothing that I can do to improve the exhaust braking effect on the 09.

rebal

Dave you might have to remove the brake and look at it there should be a orfice in the butterfly if there is add vacuume to the diaphram and see if its closing all the way if not adjust it till closed you will also see if there is a problem with the butterfly valve itself. hope that helps.

CoastalDav

Rebel;

Thanks for the reply. I may have to do that when I get home in November.

Dave

carl48

as they stated above you will have to take it out and adjust the linkage so that the butterfly is at the right angle to have the least restriction to flow and fully seat when energized. the best thing you can do is throw it in the trash and get a bd. the bd will hold 60 psi all the way to idle going from a jake to a bd will be like turning on a light switch. that pump is expensive and fails often. if the diaphragm fails it is not to bad but when the pump fails it locks up and burns the serpentine belt up before you can get stopped. if you keep that piece of junk on your truck carry a stock belt with you to bypass the pump when this happens. i was near Pecos Texas when one failed on me it was on a Friday night no one had a belt or pump it was Tuesday before i jot going again a four day vacation in July in Pecos Texas on foot is not my idea of a good time.

KATOOM

Manually re-adjusting the butterfly is an option but what you have to be careful of is making sure that you set the valve at just the right "maximum" angle or what you can end up causing is the butterfly to get in a position where the exhaust pressure pushing against the valve will stop it from being able to overcome the pressure against it and will stay closed until the pressure reduces. For this reason, some EB butterfly valves will not "fully" shut and this is also why there is other types of open/close designs.
I still would make sure what you weren't experiencing was the "warm up" feature.

carl48

katoom his 06 feature either opens it or closes it. no in between. and it only works if the brake is on and foot off of accelerator. like i said the bd has way more breaking power at all rpm ranges. the jake is old technology. as our jake pumps fail we switch to the bd and reuse the jake ecm and switch wiring

KATOOM

I only say this because I was told by Pacbrake that the ECM on the 3rd gen trucks enable an exhaust brake warm up feature which works like I described. Maybe Pacbrake is the only one who offers this feature but I would think that if the "feature" comes from the ECM then more exhaust brakes should be work like that too.