Why are exhaust brakes soooo expensive? Homemade brake possible??

[Torque King Jay]

First of all I just want to say that this is a great forum and the information I've gained here has pursuaded me to convert from Ford (the last 18yrs) to a Dodge with an HO CTD 6spd. What hurts the most about this is the wait. I ordered the truck back in Oct and the dealer is expecting it in 3 weeks.



I've already ordered a bunch of stuff to put on it when I get the truck, but one of the coolest things out there is the E-brakes. But here is my question... why are exhaust brakes sooo expensive :--)??

Are they gold plated?? or Are they made of 6-4 titanium or something??

From what I've seen they look pretty simple. Here is the big question:



Has anyone built their own exhaust brake?????



There doesn't appear to be anything mysterious about it. Correct me if I'm wrong but from what I've seen it can be either vacuum actuated or solenoid actuated. The butterfly closes and it has some sort of a bleed hole in the plate. The body of the brake body seems to be made of steel and the linkages to actuate it seem pretty simple.



Do you think I can fabricate my own and save some big $$$$. I have a good back ground in welding and metal fabrication plus I have access to all kinds of machine tools.



I'm open for advise. You guys are the experts

 

[SRadke]

I suppose you have a point. The mechanics are very simple but as with anything I'm sure there is a lot of engineering hiding behind the scenes. Also keep in mind the harsh enviroment this thing works in.



-Scott

 

[dremelts]

You're probably right - there is nothing exotic about an exhaust brake. The only thing you may have to be careful about is the butterfly shaft/hole tolerances. You want it loose enough that it is not going to bind up when it gets good and hot, yet you don't want it too loose either.



Most of us probably don't have access to all the machine shop equipment that would be needed to fab one from scratch.



I bought the PAC-brake because if was the least expensive and was given good marks by those who had it. I've used it now for over a year and like it very well. I guess I'm one who likes the peace-of-mind from having something that is researched, engineered, tested and proven - even if it is a bit more expensive (JMHO).



Another thing to consider is the fact that you have a brand-new truck and the dealers are already looking for any excuse to void your warranty. I think they have been willing to overlook exhaust brakes because they are offered as optional equipment, but a homemade one may void your warranty.

 

[klenger]

Remember that it has to work at 1300 degrees.

 

[Mopar_Mudder]

One of the big reasons is that you are not just buying a brake, you are also buying what ever runs it. In the case of the Jacobs brake that i have that is a vacuum pump, brakets and belt to bolt it to the front of the motor, that is a fair amount of stuff right their. It also comes with what it takes to control it, including the gear shift switch inside and the hook up to plug it into the Cummins computer so that it works with the throttle position and temp sensor.



So you can see that their is much more to it then a simple vavle in on the exhuast system. Their are some cheaper ones out their that just splice into the exaust pipe, but the good ones replace the elbow that is right on back of the turbo, the closer it is to the trubo the better it works.



Depending on your situation, when I bought mine I got a special $500 credit that I could use toward extras for buy the truck for business use. I used that toward the exhaust brake, don't know if that is still available.

 

[LPChristensen]

Hey Torgue King, I might tend to agree with you somewhat about the price, they are high dollar. But having had the opportunity to buy the Jacobs/Cummins kit, looking at the quality, looking at the number of parts that come with the kit, I think it's a fair price, all things considered. After all, we seem to be spending as much for a truck today than we did for a small house several years ago! Beside the other reason given on this thread, there is also the electronic program aspect of the factory Jake brake to consider, the automatic shut off if you are using it to warm your Cummins up on a cold day and the two second delay that allows you to shift without the brake being activated. One other point, when I am going down a mountain in Colorado with several tons behind me, I want to be assured that when I pull the switch for the Jake brake what will happen will be be my truck and trailer slowing down and not a bunch of homebuilt parts from Pep Boys or Napa being left on the road. I am not saying that you could not build one as well as the Jacobs/Cummins kit, but I will bet that to do it right, you will end up spending more than the kit.

 

[Torque King Jay]

Thanks for all the info. I've looked at all the exhaust brakes you guys have talked about and I think that the Jacobs and the Pac are pretty nice. I wasn't sure about the electronics aspect of the brake, but you've cleared up some questions.



I'm going to keep researching the "home made" brake system and talk to some guys at work that had worked on some exhaust manifold projects we did about 2 or 3 years ago. The air compressor or vacuum pump was something I was not thinking deep enough into. I see the added $$$$ for all the extra gear.



I have some more questions if you guys have some time.



Does the air pump or vacuum pump have a reserve tank to hold pressure or vacuum to allow the pumps to be turned off or disengaged?



The warm up feature is nice, but will choking off the exhaust on a cold engine create other future premature wear issues with the motor?



The more I talk about this the more I feel the "need" to have one . Since this truck is just a toy that will probably only get driven on the weekends and I tow nothing heavier than about 3500lbs the brake is being installed just because it's cool Oo. Oo.

Isn't that what bombing is all about???

Thanks guys Jay

 

[y-knot]

Sorry, but I think this falls into the same category as building your own gooseneck hitch. Both could be done by a somewhat mechanical person, but why? The end result will not be of any higher quality, truth is it will probably be less, and will look "homemade". The Exhaust brake may seem to be low tech and very simple, but I would think most people would be surprised as to just how much engineering goes into there product. The brake must live and work in a very confined and high temperature world. It is asked to flow with out much restriction while off, but seal while on. Also the operating environment has a huge temperature swing, going from 2-3 hundred degrees up to 13-14 hundred degrees, all the while it's inner workings must maintain the close tolerance demanded for a good seal. The movement must also stay smooth and steady thru-out this operating range. Truth is , most owners would not be able to make a E-brake that works as well as the ones sold. Same goes for the hitch. If you want to complain about something, complain about the fueling boxes, they are very cheap to build and sell, yet no-one gripes about the cost.

 

[LPChristensen]

Jay, the Jacobs/Cummins brake works off a vacuum, there is not a reserve tank. The other brake, the Pac Brake, works of compressed air and they have a tank set up. The Jake brake does not cause premature wear issues when used during the engine warm up, it was co-designed by Cummins and Dodge and as such is under warranty, both brake and engine, should a problem arise. The Jake brake is cool. One of these best things about it, besides it's intended function of braking, is when you have the brake on, and if you have a good flow through muffler, it sounds great when you are slowing down. I have never heard a diesel engine sound as good! I had my buddy drive my truck by me several times so that I could hear the sound for myself, it was music! Also, from what I have read and learned about the Jake brake, if used normally, on the highway and around town, your truck's brakes are supposed to last 35-50% longer, another added benefit.

 

[SRadke]

The Pac Brake does have a compressed air storage tank as an option but it is not required to use the brake. When the brake is activated the compressor turns on and fills the line and air cylinder up to 100 psi. This such a small volume it takes less than a couple seconds to do but becuase it doesn't just slam the air in there from a tank it provides a very smooth engagement.



-Scott

 

[9412v9824v]

ok so me to as in onboard with building a homemade exhaust brake... i am just wondering what the max back pressure a 12 and 24v will take before floating? but as far as the mech of an exhaust brake it is very simple and could be run with a choke cable if you wanted to be the simple. as far as running at up to 13 or 1400 degrees yes thats possible too if you mount it right behind the turbo... but an exhaust brake can be mounted anywhere in the exhaust after the turbo as long as you have no muffler in place as i do not. if you have a muffler it jus needs to be before the muffler and behind the turbo. i am planning on making my own exhaust brake i will hook up a back pressure gauge in the exhaust and adjust accordingly by putting a hole in the flap in the exhaust and testing till i can completely close the valve and not exceed the max recomended back pressure for a 12v and 24v as i have 2 trucks and plan to build one for each. . i also posted a thread asking anyone if they know what the max back pressure is for a 12 and 24v any imput on that is appreciated thanks

 

[rscurtis]

Keep in mind that a lot of the price of a first-rate product is the cost of parts, service, and technical backup. There is, or should be, a sustainable profit margin built in also.



After attempting to build your own, you will find out that it's not as simple or easy as it seems at first glance.

 

[9412v9824v]

well ive read and looked and researched many sites ppl and places... its a very simple design... . open and close only factor that is an issue is insuring you dont run up to much back pressure so not to float your engine... this can be achieved by trial and error off opening and closing the valve starting with a small hole and drilling it bigger and bigger or you can use a variable open and close setup so flap only closes to a certian back pressure... or you can use a simple valve spring itself with a bolt and a washer on the flap so say you have a 40 valve spring on the flap... when 40 is reached for back pressure the spring will compress letting exhuast flow by... . simpliest in my mind is setting up a variable open close setup but none the less what is the stock pressure on 12v springs?

 

[Prairie Dog]

I bought a used one. Guys were upgrading from the standard Pac brake to the PXRB by purchasing a whole kit and then selling the old ex. valve assembly with the compressor and other new parts from the kit - so only the valve was used. I paid $600 for the setup and it has been money well spent.

 

[seafish]

It CAN be done as long as you are mechanically inclined and have excellent fabrication skills.



This one is homemade AND REALLY well done...



My Homemade Exhaust Brake - Dodge Cummins Diesel Forum

 

[RustyJC]

... but an exhaust brake can be mounted anywhere in the exhaust after the turbo...

Actually, there's a factor in reciprocating compression called "fixed clearance" or "clearance volume". In a nutshell, the more clearance that exists at the end of the compression stroke, the lower the compressor's volumetric efficiency will be. That's why reciprocating compressors will often use volume unloaders to reduce their throughput capacity and compression horsepower.



In this application, the more volume you have between the exhaust valve(s) and the exhaust brake, the less efficient the exhaust brake will be.



Rusty

 

[9412v9824v]

yes i have seen that before and wanted to contact gentleman who made it to see if he wanted to make another but i have not been able to lol

 

[9412v9824v]

ya ived seen that one before and wanted to contact guy to see if he wanted to make another lol but no luck... and also ya id buy a used one if someone hada good deal on it but 1k is just stupid

 

[9412v9824v]

sorry for double post... my laptop was acting up not showing me that i posted already computers ughh lol

 

[jelag]

I haven't read all the threads... but after selling pacbrake for almost 20 years here's my $10 worth of advice...



Buy a brake with in house engineering and dyno's... and hopefully one with 100% in house manufacturing... that will bring you down to 3 manufacturers...



Why... . you need the assurance that the back pressure will never exceed 60 PSI because at about 65 PSI there is enough back pressure to push the exhaust valve open under certain conditions, which would result in catastrophic failure when that valve is pushed open with a piston coming up...



Second, you'd want one that interfaces with the engine computer so that on cold days the ECM can turn on the exhaust brake to help warm up the truck.



Third, you want one that will interface with the ECM and turn on the brake automatically as you go down the road with the cruise control on.



and last, you want to use it all the time so that it won't carbon up...



I call this a seamless interface, and I'm betting that a good percentage of the guys here bought their pacbrake from me, when I was in the business for the reasons mentioned above...



I you wish the really long version drop me and email and I'll send you my cell #... .



Remember that PacBrake still sells more exhaust brakes and engine brakes to the military for their trucks than most of the other manufactures...



I guess I can step of the platform, but I'm no longer a vendor here so I guess I get to speak in the open forum.....