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E7 eng brake


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The one on my '04 AC Engine is pretty strong. It works pretty decent at 1700-1900 rpms. I try not to use it any higher than that just because I don't want to accidentally over-rev it. I think it works just as well as the one I had on my Kenworth with a C-15. Except the Mack is only a 2 stage. My Cat had 3 stages.

I do mostly local city and rural driving. I have it turned on basically all the time. It's perfect for back road stop signs and city red lights. I've gone down some pretty big hills at 80,000 lb plus. But I've never used it descending a mountain. So I can't speak for a long downhill distance.

But I think for a 12 liter engine, it holds its own.

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OK thanks for your input. I definitly like the way my e6 runs I havent hardly touched it other than normal maintenance but the kicker is the weak engine brake. A good jake makes a world of a difference in brake usage lol

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  • 2 weeks later...

drive slower, less need for jake brakes, how about coming across 70 in Utah from 15 to the Moab turn off pulling  loaded 13 axle with tuned Cummins 315 with no jake, never smoked brake, Oh then go down from Moab to Farmington NM. then 550 to 25 to 40. not bragging but somehow trucks got coast to coast without jakes not that long ago, most road jockey's use the jake as a truck stop toy.:P   

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13 minutes ago, Mackpro said:

Even when new, the ETECH Jacobs brakes were so weak that the later trucks had the option of turning on the air fan when the engine brake came on to help slow the truck.  This parameter was turned on in the VECU software, we rarely turned it on. 

We had a pow wow on how bad the early engines were.......our "crack-pipe" plan for the engine was to have the Jake relay also power a solenoid valve that applied 10 PSI of regulated air to the brake system and had a loud audio recorder in the cab that went POP POP POP POP POP POP POP .

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Most issue was getting enough oil to the top of engine to feed engine brakes. While your looking at trucks you will see units with external oil lines feeding the valve cover base housing, that tells the story. They tried...

1. high volume oil pumps

2. tighter main bearings

3. external oil lines

4. upgraded rebuild kits that let Jake run on less volume

IMO the final Mack Powerleash was the only good (gray engine) performer they made.

 

powerleash.pdf

Edited by Mack Technician
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what year did they add the external oil lines? i have a 2000 year motor and my cousin has a 2001 i think and he had oil feed line that i didnt so then i had it added.  

the engine brake on my 2005 375hp Alison 6spd auto felt alot stronger then the one in my 2000 CL 427hp 

Edited by 2000CL713

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28 minutes ago, 2000CL713 said:

what year did they add the external oil lines? i have a 2000 year motor and my cousin has a 2001 i think and he had oil feed line that i didnt so then i had it added.  

the engine brake on my 2005 375hp Alison 6spd auto felt alot stronger then the one in my 2000 CL 427hp 

They started July 2, 2000.

2005=powerleash:thumb: 

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Early ETECH Jake brakes we known to be weak or just quit all together after 500,000 or more  miles. Adding the update kits, external oil line kits and the high volume oil pump would restore them from the dead and make them stronger. But at a high price and most guys around here said to hell with it and didn't install the update kits. I think I put on one external oil line kit. Biggest issue we saw was bad solinoids/o-rings and the freeze plug falling out of the end of the rocker arm shaft. 

 

Edited by Mackpro
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17 hours ago, 2000CL713 said:

Can the powerleash setup be installed on the older motors (2000)? 

Would cost too much, camshaft/tubes/pump/covers/liability/etc. Follow Mpro's SB-recipe and you have a "good enough" brake without redesign. 

We used to drop the pan, leave it as a catch pan and hook the shop motor oil fill system into the engine oil gallery. I would lay under while one person would pressurize the engine. We would note the amount of oil loss from the cam bearings. If the bearings looked tight we would start small on PI updates.   

Edited by Mack Technician
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You can by a lot of brake shoes with the money your going to spend on patching this And it will be a patch these dint work that well even with all the line bearing and other patch kits!

Just sayin!

Edited by fjh
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question- if you go buy a new oil pump now do they only sell the high volume or do you need to request it? since they phased it in does it just become the shelf part. i dont see why they would offer both now since that one is better and was put into service to take the place of the older one.

Edited by 2000CL713

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2 hours ago, fjh said:

You can by a lot of brake shoes with the money your going to spend on patching this And it will be a patch these dint work that well even with all the line bearing and other patch kits!

Just sayin!

You are correct. We would repair the o-rings on the  solinoids and solinoids if bad.  Add the anti-drain back screws on top of the rocker arm shaft and may be the high volume oil pump. But anymore than that and the owners usually gave up and wouldn't  spend the big dollars for the external oil line kits and the upgrade rebuild kits. 

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2 hours ago, 2000CL713 said:

question- if you go buy a new oil pump now do they only sell the high volume or do you need to request it? since they phased it in does it just become the shelf part. i dont see why they would offer both now since that one is better and was put into service to take the place of the older one.

Yes they only make the high volume pump now . 315GC466MX is the part number

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15 minutes ago, Mack Technician said:

(2000CL) Seems like your immersed in sharpening the edge of this truck.....is it a dandy or just generally needy?

i come from a background of modifying cars highly for racing and street use. i only like to have the best within reason (not suffering reliably). if im going to take a part off to fix anther part and they make a better part(s) and its already off i will replace it for a better performing truck. i take pride in my truck. yes it has all the chrome and lights on it and not in a tacky over done way. all my trucks have been like this. when i custom ordered my CV713 in 2005 it was a big thing. Mack took it shows. big poster was in the sales department. in the Mack news letter and parts mag. i think i still have a copy somewhere lol my CL is coming up on almost 20 years old and stock parts are starting to show some age and im wanting to redo a few things. change it up. upgrade things while im at it. 

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