Engine/Transmission (1994 - 1998) Which exhaust brake works best?

[esamuelson]

I am thinking of putting an exhaust brake on my truck and wondering what one seems to work the best. A friend of mine has a 6. 7 cummins with a factory setup and I was really impressed with it except it didn't seem to work real well at low rpms, still better than nothing. Thanks for any info.

 

[AEdelheit]

I have the PacBrake PRXB and love it, had it for 70k or so and never had a problem, works way better then a 6. 7 exh brake.

 

[CKelley1]

the bd and the pac are the best and hold the same all the way to idle i prefer the bd over the pac because of the compressor mount. if you get a pac, mount the compressor somewhere else besides the engine compartment. once we did this all of our problems went away. your truck has 30 lb springs. call bd and order the bd and 60 lb exhaust valve spring at the same time. the intake springs can stay stock. the bd and pac hold back two times better than the jake and maintains 60 lb pressure all the way to idle where the jake never reaches 60 at 3200 rpm and is near nothing at idle

 

[ewcmr2]

BD for a 12v is vacuum operated, so no compressor to deal with.

 

[Bob V]

Unless things changed the second gen brake should be vacuum operated and not use a compressor

 

[RSchwarzli]

I run a PRX and love it! I run as already stated, 60 psi until about idle where I run 40 psi.



Going down a 8% grade at 70 MPH with 12K lbs behind, 18K GCW, I did not touch the brake pedal. Kind of an odd feeling!



Also having a 6. 7, I would say the Pac Brake is about 2x as powerful.

 

[mtarcher1]

I've had a vacuum operated Pac on my '95 for a few years now. I tow a steel stock trailer with 2 or 3 horses (around 9000# gross) in the mountains along the continental divide here in Montana. I don't have experience with other exhaust brakes but can say I'm happy with the Pac. It has been trouble free and allows me to stay off the service brakes coming down off most passes. I had to install the stronger valve springs but didn't have to deal with mounting a compressor. The flip side though... I believe a compressor operated unit can be used on your truck and having a compressor on board can be handy.

 

[CKelley1]

the vacuum bd is not as good as the air. the vacuum pac is built like the jake. get the air one you will be glad you did. i think the vacuum pac was also set at 30 psi

 

[Grizzly]

I vote for the PacBrake, well because that's what I have and am very happy with it.



george

 

[Bill Stockard]

the vacuum bd is not as good as the air. the vacuum pac is built like the jake. get the air one you will be glad you did. i think the vacuum pac was also set at 30 psi

The old original vacuum operated Pacbrake like I had on my two second generation trucks was set for 30-PSI; however, if the engine had the 60-lb valve springs installed, a plug could be installed in the orifice in the flap which raised the maximum back pressure to 60-lb. At the 60-lb setting, it was very effective down to about 1200 RPM. For the most effective exhaust braking, I would shift down to keep the engine RPM up.



Bill

 

[CKelley1]

if you get the air it will hold 60 lb all the way to idle

 

[ewcmr2]

the vacuum bd is not as good as the air.

Better how? Performance, reliability, installation...



Comparing apples to apples, both air and vacuum actuated, set up for 60 lb valve springs, I don't see how the engine can tell the difference in what power source closes the butterfly. If you're talking vacuum set up for 30lb vs. Air set for 60 lb, well, duh.



Reliability, I'd predict a factory installed Cummins gear driven vacuum pump will be more reliable than a consumer installed electrically driven aftermarket compressor.



Installation, I'd prefer to plug in a vacuum tee over mounting and wiring a compressor.



If your driving a newer truck without a vacuum pump an air powered exhaust makes sense but here in the 12v section that doesn't really apply.

 

[klcammie]

Ijust had a Pac brake installed on my 24 valve 01 6 sp. It has 60# of hold and works on vaccum. It is the best thing I've done to my truck.

 

[Breed]

I have a Pac Brake on my 98 12 Valve and it works great!

 

[CKelley1]

the vacuum one is built like the jake and has a hole in the butterfly to limit the pressure to 60 lbs at sea level and 3,200 rpm. as altitude increases and or rpm decreases the pressure drops accordingly. the bd and pac air work differently. the bd has a solid butterfly and a air regulator sets the pressure to where it takes 60 lb to open it therefore you have 60 lb back pressure at idle at 12,000 feet elevation. the pac uses a spring and ball to cover the orifice and takes 60 lbs to push the ball away. there is night and day difference between the vacuum and air. we tow heavy and still have a few trucks with the vacuum. we have two trucks same year and same gearing. one with a jake and one with bd. it is instantly noticeable between the two. i run both the bd and pac i have had a few failures with the pac compressor because of where they mount it. once we moved them we have never had another failure. and we have never had a bd failure

 

[RSchwarzli]

Ck -

you mentioned noticable performance difference between the bd and PAC? Can you expand on that a little? In what way? Stopping power or overall userfriendlyness?

 

[m1ashooter]

I have the Jacobs EBrake on my 98 12V 5 spd, a friend has the Pacbrake on a 98 12v 5 spd, after being in both trucks towing my jetboat, I really couldn't tell much difference, they both work really good.

 

[budnate]

Guys a question as I know zero about these but have been curious about them , can you add a exbrake to a hi mile 12V, AutoTrans motor like around 260k... do you increase the odds of blowing a head gasket useing one??

 

[CKelley1]

first the air pac and bd are equal in stoping power. i have a preference of the bd over the pac because of where the compressor mounts. budnate it does not produce enough head pressure to be measurable. it is around 1,000 psi or more lower than point of ignition. on a 1991 with over 1,000,000 miles on it and had a exhaust brake on it most of it's life and no problems. i would never touch a truck with a automatic but from listening to others who have either driven one or owns one that you may have a problem locking the transmission up.

 

[Dieseldemon]

You need a convertor lockup switch with the 98 12v to use an exhaust brake