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Topic: Adding a Jake brake  (Read 4913 times) previous topic - next topic

Re: Adding a Jake brake

Reply #80 –
When I did the fuel lines I ran 4 spare wires to the storage space. One was to be used for
giving the Allison computer a signal so when I'm using the Jake brake the trans will
call for 2nd gear and will shift down automatically as RPM is appropriate. In working
with the Allison dealer here I found that Foretravel had the wire from the computer to under the dash. 
Having a tone tracer sure makes it easy to find the wire under the dash. We have a great Allison dealer
here. They are so helpful and it the computer needs to be programed to second gear
they will do that with out charge.  The computer may be programed for 4th gear, I will find out soon.

Re: Adding a Jake brake

Reply #81 –
Quote from: oldguy –
When I did the fuel lines I ran 4 spare wires to the storage space. One was to be used for
giving the Allison computer a signal so when I'm using the Jake brake the trans will
call for 2nd gear and will shift down automatically as RPM is appropriate. In working
with the Allison dealer here I found that Foretravel had the wire from the computer to under the dash. 
Having a tone tracer sure makes it easy to find the wire under the dash. We have a great Allison dealer
here. They are so helpful and it the computer needs to be programed to second gear
they will do that with out charge.  The computer may be programed for 4th gear, I will find out soon.


The Allison computer can be programmed for ANY gear you want as your pre-select gear for retarder (or in other coaches an engine brake).

No right/wrong answers.  More driver control, but requiring more driver input= 5th gear pre-select.  Great for coming to a stop, but likely to "over-brake" on the road= 2nd gear pre-select.

Choose what fits YOUR needs.

Re: Adding a Jake brake

Reply #82 –
I want mine set to 2nd gear as I am setting it up so I have a choice whether I use it
or not. If I just want to maintain the speed going down hill I will manually shift down
and if I want to stop or really slow down I will call for second gear. The wire I am using
is dead ended under the dash, not hooked up to anything. When I'm using the retarder it has
never felt to me that there is force down shift. I have never seen the engine rev up.

Re: Adding a Jake brake

Reply #83 –
That MAY be the correct choice, but consider a 4th or 5th gear preselect.  Then use the down arrow to select lower gears.  That is a better choice on mountain grades, but agreed, 2nd is better if you are coming to a stop and don't want to fool with the down arrow.

Re: Adding a Jake brake

Reply #84 –
Quote
More driver control, but requiring more driver input= 5th gear pre-select.  Great for coming to a stop, but likely to "over-brake" on the road= 2nd gear pre-select.

The Jake on my 95 was a single speed with a 4th gear pre-select. I changed it to a two speed with a 5th gear pre-select and found that to be a more pleasurable driving experience.
jor

Re: Adding a Jake brake

Reply #85 –
I  had mine programmed for 5th as well.

Re: Adding a Jake brake

Reply #86 –
I have put in a second floor switch for shifting down and I will use it when I want
to slow down or stop.  When going down hills I have lots of time to manually shift
down as I have been doing which works great for me. It's when I need to slow down
quickly that I find it awkward trying to get at the shifter control and push it a whole
pile of times.

Re: Adding a Jake brake

Reply #87 –
Arrived at June Lake, CA a couple of days ago after battling 60 mph gusts and then snow last night. Driving through the Sierras, the Jake is perfect. Never too much, never too little. It has been switched on ever since we bought the U300. It might be a slightly stronger on a 4 cycle but then you have the 3 cylinder position. It shuts off just before you get to a stop so is just one of those rare things that works as good or better than advertised.

The sound is so good driving through towns with the Detroit, I expect to get a recording contract soon.  ;)

Pierce

Re: Adding a Jake brake

Reply #88 –
Jor sent me a message as to how I put in the floor switch so I think I should add
it to this link. From the picture the foot switch on the right puts on the Jake and
the one on the left is to preselect a gear in the trans which for me is 2nd gear.
What I have done could be done with one switch but a relay would be needed as
the Jake is grounded to work and the preselect is powered. So I powered the switch
though the ignition with a fuse down to the left switch and from the switch to one
of the yellow wires in big cluster of wires. The yellow wire goes to #11 on the black
plug in the computer. I will go out on Sunday and try it out. There is no right way to
set this up, this is how I want it to work for me.

Re: Adding a Jake brake

Reply #89 –
Went for a drive this morning, the Jake is working the way I want. It is
set for 2nd gear. Scott wanted to know how loud it is with a resonator and
it is loud. I can really here it, before I couldn't here it. Now I have to go and
remove a hydraulic line as one blew and will get a new one made up first thing
in the morning. The coach is about 15 minutes from.

Re: Adding a Jake brake

Reply #90 –
Driving to the Ferry I got to use the Jake for a lot to stop lights, pushing the second
switch it calls for second gear and slows the coach quickly. Going down the back side
of the bridge shifting the trans to 4th held the coach perfectly and at the bottom I
was catching up to traffic pushed the second switch and slowed right up. Only using
the bakes to stop.

Re: Adding a Jake brake

Reply #91 –
Coming home from Saskatuwan I took the #3 highway and got to really try out the
Jake Brake. On one hill I was able to pass 2 semis on a 6 to 8 percent grades. Most
of the steep grades on that route have sharp corners on the hills and usually at the
bottom so I would use the retarder to bring me down to speed. There is three big
passes on that route. Before we got to the #3 highway we were on another grade
that was 6 and 8 percent and at the end was a 11 percent grade with a 20 mile an
hour corner at the bottom. That was fun. On one descent the torque was getting
hot and I used Scotts idea that I could turn the fan to high speed with a switch.