Honest experience and opinion of Mopar Jake Brake
12-30-2007, 10:47 AM
#16
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I have the Jake brake on mine mostly because of the warranty, it works great I have had not issues as of yet with about 15000 on the unit.
I didn't like where they wanted me to mount the switch (gear shifter; automatic) so I did some mods and put it in the consol area under the seat heater switch.
I leave the brake on all most all the time unless it is real slick out and I am not in 4 wheel drive. I do this becuse I am so use to it slowing me down and of course it is saving my brakes.
I bought mine right from Cummins as it was about $250 cheaper and installed it myself, the belt was the biggest pain. I also installed one my cousin truck and the belt again was the biggest pain.
Could luck and IMO which ever brake you go with you will be very pleased that you have one installed
I didn't like where they wanted me to mount the switch (gear shifter; automatic) so I did some mods and put it in the consol area under the seat heater switch.
I leave the brake on all most all the time unless it is real slick out and I am not in 4 wheel drive. I do this becuse I am so use to it slowing me down and of course it is saving my brakes.
I bought mine right from Cummins as it was about $250 cheaper and installed it myself, the belt was the biggest pain. I also installed one my cousin truck and the belt again was the biggest pain.
Could luck and IMO which ever brake you go with you will be very pleased that you have one installed
12-31-2007, 01:09 PM
#17
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I had the Jacobs brake installed on my '06 when new, and at the time it seemed like the logical choice, because it was "Dodge recommended". However, I would not do it again.
You do have to use a different serpentine belt to accomodate the vacuum pump. However, it is NOT safe to say that you can just carry the original belt to bypass the vacuum pump in case of failure.
I was heading out for vacation with 35,7xx miles on the OD when the vacuum pump siezed up. When it siezed, it instantly smoked the serpentine belt nearly catching it on fire if I had not stopped instantly on the interstate (not a smart thing to do in itself). Then, when the belt snapped, it took out the belt tensioner/pulley assembly and sent it flying into the back of the radiator. Somehow, the fan shroud also got broken in the process.
Needless to say, my spare belt did me no good, and the vacation was cut very short. It is a VERY common problem for these vacuum pumps to wear out every 30k - 40k miles.
Finally, all brakes are not equal in performance. The Jacob's unit uses a fixed size orifice (holes in a butterfly valve). The holes are sized so 60 psi backpressure is not exceeded at max rpm. This allows for great braking at redline rpm, and significantly less braking as rpm drops.
Pac and others, uses a variable orifice, that attempts to maintain maximum allowable back pressure with decreasing rpm.
The Jacobs works well when it's working right, and when constantly shifting to keep it in the upper rpm band. However, I do not feel confident in the longevity of the system at all...and even though it may be under warranty, a failure can cause much heartache when it happens at the worst possible times.
--Eric
You do have to use a different serpentine belt to accomodate the vacuum pump. However, it is NOT safe to say that you can just carry the original belt to bypass the vacuum pump in case of failure.
I was heading out for vacation with 35,7xx miles on the OD when the vacuum pump siezed up. When it siezed, it instantly smoked the serpentine belt nearly catching it on fire if I had not stopped instantly on the interstate (not a smart thing to do in itself). Then, when the belt snapped, it took out the belt tensioner/pulley assembly and sent it flying into the back of the radiator. Somehow, the fan shroud also got broken in the process.
Needless to say, my spare belt did me no good, and the vacation was cut very short. It is a VERY common problem for these vacuum pumps to wear out every 30k - 40k miles.
Finally, all brakes are not equal in performance. The Jacob's unit uses a fixed size orifice (holes in a butterfly valve). The holes are sized so 60 psi backpressure is not exceeded at max rpm. This allows for great braking at redline rpm, and significantly less braking as rpm drops.
Pac and others, uses a variable orifice, that attempts to maintain maximum allowable back pressure with decreasing rpm.
The Jacobs works well when it's working right, and when constantly shifting to keep it in the upper rpm band. However, I do not feel confident in the longevity of the system at all...and even though it may be under warranty, a failure can cause much heartache when it happens at the worst possible times.
--Eric
12-31-2007, 10:39 PM
#18
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They do. The ECM bypass kit is meant to get the brake to cut in faster than the 2-3 second delay that normally occurs after taking your foot off the accelerator. However, mine already does cut in instantly without that kit - maybe some new ECM programming in the '07's. This instant cut in makes upshifting interesting, especially when towing as your RPM drops real quick with the brake on and no engine load when stepping on the clutch.
I got the clutch switch in yesterday and test drove today. Very nice! Brake does not cut in while upshifting (basically interrupts signal from switch to ECM while clutch is depressed), but yet operates otherwise as normal. It was a bit of a pain to figure out where it goes as no instructions were sent, but it is done nonetheless.
I got the clutch switch in yesterday and test drove today. Very nice! Brake does not cut in while upshifting (basically interrupts signal from switch to ECM while clutch is depressed), but yet operates otherwise as normal. It was a bit of a pain to figure out where it goes as no instructions were sent, but it is done nonetheless.
01-01-2008, 01:21 AM
#19
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empty, i think it works ok. when my "friends" truck grossed 42k i honestly had to look and see if the light was working because i couldnt notice any assistance. when the trailer was empty, it still didnt do much.
like i said, unloaded its does decent(just the truck)
brett
i have 30k miles on it too
like i said, unloaded its does decent(just the truck)
brett
i have 30k miles on it too
01-01-2008, 11:43 AM
#20
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I went with the Jacobs because its Cummins endorsed, nuff said... It works quite well, and hasn't given me any issues, nor my dad. If your worried about not enough braking power just keep the rpms up.. If you drop below 1900 (man) then downshift... between trailer brakes and EB you shouldn't have to touch your service brakes... in fact I have to turn my jake off at times as it brakes too much 
Second... it has a 3/100 on the brake and 3/36 on the rest of the components.
Third... the 6.7 does NOT have a Jacobs exhaust brake.. its a EVGT that uses the turbo vanes to block exhaust flow...
Jacobs driving instructions
Second... it has a 3/100 on the brake and 3/36 on the rest of the components.
Third... the 6.7 does NOT have a Jacobs exhaust brake.. its a EVGT that uses the turbo vanes to block exhaust flow...
Jacobs driving instructions
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