# Installed Jacobs Exhaust Brake On My Truck This weekend!



## Live Oak (Dec 22, 2003)

Or to put it more accurately, I assisted my friend Jim who already had experience installing his.  All I can say is WOW! What a difference! I should have done this sooner. Makes maintaining speed on steep grades effortless and save BIG TIME on service brakes. The install would have taken about 2 to 3 hours but we ran into problems trying to remove the cigar lighter (believe it or not) :argh: We finally got things figured out and then the pace picked right up. 

The exhaust brake I bought was a Cummins model. I bought through Wendy at Southeast Diesel Power for $625. It is manufactured for Cummins by Jacobs and is authorized for install by Diamler Chrysler with no effect on the vehicle warranty. Here is a bit of background info. on the brake:



Jacobs Exhaust Brake For Cummins Powered Dodge Ram 

My truck is a 2002 model so this particular exhaust brake kit comes with a dash mounted activation switch which can be a real pain in the butt as far as ease of use. I purchased a Cummins "stalk switch" which is a plunger type activation switch that mounts to the shifter. This stalk switch is not part of the kit and must be ordered separately under Cummins part # 4089657. I purchased it through Wendy at South East Diesel Power in Orlando FL for about $77. It lists for about $100. The stalk switch actually looks pretty cool and fits the truck perfect with nice Cummins logo and a slick clamp to hold it on the shifter. Just be aware that this stalk switch is a component part for the 2003 to 2005 Dodge Cummins pickups and you will have to order it separately. It is just a matter of splicing it into the exhaust brake kit wire harness. I am not certain if this stalk switch can take the place of the dash mounted switch and harnes or not as the switch harness must be plugged into pin 20 of the ECM main connector plug. The pins on the stalk switch looked like they might work but we did not want to take the chance on damaging the ECM. WELL worth the cost in my opinion. 

Here is a picture of the stalk switch:

<img src="http://www.tractorforum.com/attachment.php?s=&postid=88000">

I tested the brake on a very steep hill that I would reach 70 mph or more in 5th gear without the brake. Now I can maintain a steady 50 mph without using the brakes at all. This will be really nice with a loaded trailer.


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## Live Oak (Dec 22, 2003)

By the way, here is a link to the original post on this project. 

Jacobs Exhaust Brake


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## chrpmaster (May 5, 2004)

Cool setup Randy.

I never did understand how these worked so I went to the web link you showed and still don't understand  

Oh well so long as it works and you're safe. How much hauling do you do? Is it a daily thing? Is it for personal or business?

Just curious
Andy


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## psrumors (Apr 25, 2004)

Andy, the way these brakes work is by closing off the exhaust or partialy. If the motor can't exhaust it creates back pressure which will slow everything down. Does that help?

I would like to add one to my '03 Cummins but just haven't had the extra cash that wasn't being used for something else.


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## Live Oak (Dec 22, 2003)

Could have put it better myself Ron!


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## Live Oak (Dec 22, 2003)

> _Originally posted by chrpmaster _
> *Cool setup Randy.
> 
> I never did understand how these worked so I went to the web link you showed and still don't understand
> ...


Andy, I did a LOT of hauling when moving here to the ranch and sure wish I had the brake installed then. I haul hay, ATV's, maybe my tractor in the future. 

I live in an area with very steep hills and rolling land. Without the exhaust brake, I have to apply the truck service brakes which can be tough on the pads and rotors. 

Upshifting has little to no effect in slowing the truck since a diesel engine has no throttle plate to cause an intake restriction like a gasoline engine does. Upshifting to slow a gasoline powered truck works well but almost not at all with a diesel. Hence the exhaust brake creates a restriction via a vaccum actuated exhaust valve that went applied creates a restriction in the exhaust housing of the turbo charger. It is designed to actuate only when there is no throttle applied. 

This is not the same as a true Jake Brake on the larger over the road trucks. That is an engine compression brake which works on a different principle.


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## psrumors (Apr 25, 2004)

And boy wouldn't it be nice to be able to fit a true Jake to one of these trucks. You could make it stop from 90 mph with out ever touching the brakes.


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## Live Oak (Dec 22, 2003)

When someone figures a way to shoe horn an N-14 Cummins into a Dodge pickup, you could!


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## chrpmaster (May 5, 2004)

Thanks guys for the explaination of how the brake works. Randy I was wondering how much weight you can haul with you setup? Did it increase after adding the Jake brake or did that just make it easier to haul and not wear out the service brakes as fast.

Inquiring minds want to know.  

Andy


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## Live Oak (Dec 22, 2003)

Legally the weight limit is what the manufacturer lists. The Jake brake does indeed make hauling a heavy load MUCH easier and tremendously reduces service brake wear. 

Arguably the Jake does increase your towing capacity but I will remain within the legal limits. My friend Jim hauls his Gehl skid steer which weighs in a bit over 8,000 lbs., a cord of wood, diesel fuel truck bed tank, tools and "stuff" on a goose neck trailer without any problems. I would estimate that he is hauling around 16,000 lbs. not including the weight of the truck which is around 8,000 lbs. 

I think the biggest benefit is maintaining control of speed on hills and the additional stopping power over and above the service brakes.


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## Lamar Holland (Dec 28, 2005)

I spent quite awhile on southeast web page. There is no mention anywhere of a "Cummins brake".. Some other name I am not familiar with... I have the 01, H.O. with 6speed, and other than changing the air inlet coming real soon, I probably will get a jake... I ordered the truck in Jan of 01 and just went over 50K miles on it recently...


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## Live Oak (Dec 22, 2003)

Jacobs actually manufactures the exhaust brake for Cummins and Mopar. Cummins and Mopar put their logo on it and assign their part #'s. Here is the info. Cummins lists: 

Genuine Cummins Exhaust Brakes for your Dodge Ram 

The Cummins website is NOT up to date with the most current part #'s. 

If you go to the Jacobs website and look up the most current part #'s; the most up to date Cummins part # for the exhaust brake that fits your truck is (Mopar P/N 82205577, Cummins P/N 3800792).

I got these part #'s from the Jacobs Exhaust Brake parts manual


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## Live Oak (Dec 22, 2003)

Here is a link to all of the Jacobs installations manuals for Cummins and Mopar covering all the various year make trucks. I would post the .pdf file here but it is 14 pgs. long.



Parts & Service Literature Exhaust Brake for Dodge Ram Truck


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## Live Oak (Dec 22, 2003)

> _Originally posted by Lamar Holland _
> *I spent quite awhile on southeast web page. There is no mention anywhere of a "Cummins brake".. Some other name I am not familiar with... I have the 01, H.O. with 6speed, and other than changing the air inlet coming real soon, I probably will get a jake... I ordered the truck in Jan of 01 and just went over 50K miles on it recently... *


Southeast Diesel Power is not a Cummins dealer. They are evidently a sister corporation to a dealer that is a Cummins dealer and they can order Cummins parts if their sister dealership has them in stock or can cross locate them. Call them up and ask for Wendy in parts. She was really helpful and got me everything I needed. All I did was provid her with the Cummins parts #'s.


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