jake-brakes

[JEccles]

hey guys, i really want an exhaust brake for my truck. trouble is i dont no a dang thing about them, all i know is when i hear one go off on one of the big peterbuilds i cant take the smile off my face. So..... i pull my car and my bikes form time to time and i next year im hoping to by a pretty decent enclosed trailor that could handle both. would there be one brake that would fit this weight class or are they all the same as far as the towing weight is concerned? has anyone had troubles installing one of them with an aftermarket exhaust already installed on the truck, do i need a shorter downpipe? is there a prefered brand? would it sound sweet with my current exhaust? i want the scoop

 

[Tcolesanti]

There are a bunch of manufacturers out there that produce "exhaust brakes" for our trucks, and fit right onto the back of the stock turbo were the cast iron elbow is. An exhaust brake is very different from a compression brake used on a big truck but the end result is the same-slowing the engine. Basically an exhaust brake has a flapper mounted in the stream of the exhaust that when actuated closes, blocking off the exhaust. A compression brake uses solenoids to open the exhaust valves when the piston reaches TDC causing the engine to act like a big air pump (and also causing the distinct sound). PacBrake, U. S. Gear, BD, Banks, Jacobs, are all names of exhaust brake manufaturers. Hope this helps. BTW these brakes don't make the same sound as the big rig compression brakes.

 

[RustyJC]

True engine brakes such as the Jake brakes used on the big rigs are a whole different animal. They lift the exhaust valves on a selectable number of cylinders at the end of that cylinder's compression stroke to prevent the compressed air from pushing the piston back down on trailing throttle. This captures the work done on the compression stroke to provide engine braking BHP.



Our exhaust brakes, on the other hand, block off the exhaust. This increases back pressure and the amount of work the engine must do on the exhaust stroke. In a much less efficient manner (due to the higher fixed clearance), the exhaust brake uses this work to provide engine braking BHP.



Any of the turbo-mount brakes for your 2002 will replace the cast turbo elbow mounted on the turbine outlet with no modifications to your downpipe. The upside of a turbo mount brake is that they minimize the fixed clearance between the engine's pistons and the brake. The downside is that it limits your ability to upgrade to larger turbochargers in the future. I have the Jacobs exhaust brake - it was installed by the dealer before I took delivery of the truck - and it has worked flawlessly.



Rusty

 

[JEccles]

curses! i want that sound..... does it even sound close?

 

[RustyJC]

It sounds, well, similar but different. I notice you're in Houston - you're welcome to come over and listen to mine. Shoot me a PM if you're interested.



Rusty

 

[RabidRam]

I've heard guys on here saying that it sounds like a hissing noise... like somebody shoved a potato up their tailpipe... er, their trucks tailpipe, that is. I too wanted a true "Jake brake", but after posting on here about it, the idea was pretty much shot down. Nobody makes one, the cost to develop it would be sky-high, and the hood wouldn't close cause of how high it moves everything up in the engine bay. Sorry to say it, but we are S. O. L. when it comes to getting that "big rig" Jake sound.



Dave

 

[JEccles]

aaaaaah man that sucks... ... i wonder if it sounds different with different pipes? mabye one with a bigger "flapper" would sound better? mabye i can make one with a 5" flapper... ... pah-pah-pah-pah-pah! hell i think i'll just lean out the window and make the sound myself... . ha!

 

[RWood]

It sounds like US Gear has a good product also. Look on www.drivetran.com. It can be ran by compressed air sound it will sound closer to a rig than the normal exhaust brakes.

 

[WestTN]

Inside the truck it sounds faintly like a Jake, but outside it sounds like a very big snake. There is a noticable hiss even with stock exhaust.

 

[NIsaacs]

Most exhaust brakes, on most Diesel engines sound like a plugged-up exhaust. However on my "01" with the BD-Brake, it sounds just like a "jake", only the sound is comming from the intake. The only thing I can figure, is the valve overlap on the "01" is different than my two 1-st gen Cummins engines. I use it all the time just to hear it more than the fact that I need it



Ya might get a tape or cd with the big truck "jake" sound, that way ya don't haf-ta open the window and do it your self



Even without the sound, they are worth their weight in gold. If you want one, buy one, you won't regret it.





"NICK"

 

[Lnwing]

mabye one with a bigger "flapper" would sound better? mabye i can make one with a 5" flapper... .

My Jacobs in-line exhaust brake was designed for the 8. 3 ISC engine, and has a 5" flapper. No pah-pah-pah, just whoosh! Sorry.

 

[JEccles]

I wonder if having an "opened up intake" makes the sound more pronounced... ... Nick did you just replace the compressor side of your turbo with a bigger housing?

 

[RustyJC]

I wonder if having an "opened up intake" makes the sound more pronounced... ...

Yes. My truck has had a Jacobs exhaust brake installed since delivery. With the stock air filter, the racket wasn't that noticeable. With the BHAF, the "bap-bap-bap" got much louder. That's because the residual exhaust pressure in the cylinder at the end of the exhaust stroke is released back into the intake at the beginning of the intake stroke. That's also why extended idling with the exhaust brake engaged tends to carbon-foul the IAT sensor.



Rusty

 

[NIsaacs]

JEccles, Rusty explained the noise made by the e-brake very well. Since the sound is comming from the intake, I would think some aftermarket filters would make the sound more pronounced. My air box and filter are stock, just minus the fender snorkle. The turbo is stock on my truck, with the direct mount brake. Like I said before, my two 1-st. gen's are quiet with the e-brake, so the camshaft profile must be different on the 2-nd. gen. or at least the 24-valve.





"NICK"

 

[Michael Gibson]

I have the B&D brake on my 04 with a straight pipe and activated at idle it sounds like like snakes farting in a long culvert However when you apply the brake against a load it sounds pretty decent. You'll never get the bark or the bap, bap sound of a true compression brake but it's not bad. If you really want that sound just wire a MP3 player with a "big rig" recording to the activation switch and be happy :-laf All the major players make a good brake. So it's a matter of where your brand loyalty lies or what your "buddies" have.

 

[Texas Diesel]

The "hiss" is only noticeable at idle. When slowing down the load you get a nice BRRRRRRRR sound. This is better if your muffler and CAT (not used on newer trucks) happens to fall off like mine did.



One important difference, the Jacobs Brake uses a vacuum on / spring off instead of the PAC Brake vacuum on/ Vacuum off. If you lose the vacuum pump the Jake Brake will default off. The Pac brake will do somewhere in between. I have a Jake on the 01 and a PAC on the 98. The PAC works slightly better and is faster to open/close.

 

[Ol'TrailDog]

This is a curious thread, imho.



I bought exhaust brakes (Jakes) in order to help brake my rigs. Wouldn't be without one now.



If you are just interested in the noise how about taping some big rig real compression brake sounds, plugging it in the tapedeck/cd, rolling down the windows (or mount an outside speaker), and turn up the sound. :-laf

 

[nunya]

I put a pacbrake on recently and I do get the big rig sound, I think the AFE helps the bark and the ultraflow muffler gives it a rumble! It sure makes noise at idle too but really helps warm it up and the best part is that it really helps slow the truck! This has been a major upgrade in safety as I pull the Co. mountains and what goes up does come down.

 

[HBarlow]

That's also why extended idling with the exhaust brake engaged tends to carbon-foul the IAT sensor. Rusty

I frequently allow my truck to idle with the exhaust brake on to keep combustion chamber temperatures up. I haven't seen any negative consequences yet but I suppose I could. My truck has rolled up quite a few miles already. What is the IAT sensor? What symptoms will I experience? Should the Jacobs E Brake be removed and the sensor you mentioned cleaned at some mileage?



Harvey

 

[RustyJC]

I frequently allow my truck to idle with the exhaust brake on to keep combustion chamber temperatures up. I haven't seen any negative consequences yet but I suppose I could. My truck has rolled up quite a few miles already. What is the IAT sensor? What symptoms will I experience? Should the Jacobs E Brake be removed and the sensor you mentioned cleaned at some mileage?



Harvey

IAT = inlet air temperature. The sensor is on the driver's side of the engine, toward the rear (firewall). I pulled and cleaned mine at about 15K and found quite a bit of carbon (soot) on it - a shot of carb cleaner took care of that!



If the IAT is excessively fouled, it throws the ECM off and fuel mileage will tend to drop off.



I, too, warm up the truck at the RV park with the e-brake on before hitching up and heading out. I'm not suggesting not to do it - just stating that it's good to be aware of the flow reversion back into the intake and the consequences (albeit minor) that it has. Just add IAT cleaning to the "to do" list every 15-20K miles.



Rusty