|
02-07-2010, 07:53 PM
|
#1
|
Senior Member
Join Date: Oct 2007
Location: Huntington WV
Posts: 1,041
|
Jake Brake Modification
I didn't like running with my jakes on all the time because the throttle was so senstive I could not consistently ease out to coast without the jakes coming on. That kind of irritated me hearing the jakes come on while coasting down a small hill.
So, I modified my jake brake circuit to have it work a little differently. Honestly, I bought a Brakeswitch, but ended up not wiring it as they recommended.
Here is how I have it working, and I'll attach a schematic if you want to do something similar. I have changed the system so that the Jakes come on when I depress the brake pedal. The jakes release when I release the pedal. They do not actuate when I roll out of the throttle. They do not "latch" when I press the brake pedal. I did this on purpose so that the jakes come on anytime I apply the brakes.
I can still turn off the jakes, by simply turining off the jake switch like you would normally do.
Here is the sweet part, by adding one additional toggle switch, I can revert back to the original setup. That is the jakes actuate and stay on when the accelerator is released. They unlatch when you press the accelerator.
I added this feature, because there are times when that setup would be useful. Such as descending a long grade. If I used my brake activated mode, I would have to ride the brakes all the way down. I wouldn't want to do that.
If you want to do this you'll need a standard 12V relay, one diode, about 20 ft of wire, and a few crimp on terminals.
Look at the schematic. Here iu what is going on. We are taking the hot wire from the Jake Brake on/off switch and interruping that wire. Just remove the panel with the on off switch, my wiring was purple with yellow stripe. Use the voltmeter to determine which wire is downstream of the switch. Mine was on the front of the switch. By putting the new brakeswitch relay in this circuit, we are using the brakeswitch relay to turn the jakes off and on. I ran two wires from the kickwell where I mounted the relay all the way back to the jake on/off toggle. I used one male and one female crimp on to simply insert the new wiring into the existing circuit. Easy to undo if I didn't like the result.
The trigger wire for the brakeswitch relay comes from the brakelight circuit. Look at the wiring schematic for the passenger kick well and find the correct wire on the terminal board. You'll have to ground the other side of the relay.
If you want to install the bypass switch that makes the jake function, simply put a toggle switch to jumper around the brakeswitch relay.
I did this a couple of weeks ago, but I didn't want to post until I had a chance to drive the coach. We took a little 250 mile trip this weekend.
How did it work? SWEET !!!!!!! I now have the best of both worlds.
You don't have to spend the 80 bucks for a Brakeswitch that I did. A standard 12V relay with a diode to prevent a voltage spike back into the brake circuit would do the trick.
If this didn't make sense let me know.
__________________
__________________
Richard Rhonda Ty and Alex Entrekin
1995 Newell # 390 DD Series 60, Allison World Trans
Subaru Outback toad
CoMotion Tandem
Often wrong, but seldom in doubt
Rhonda's chronicle https://wersquared.wordpress.com/
|
|
|
02-08-2010, 03:20 AM
|
#2
|
Senior Member
Join Date: Feb 2006
Location: Texas
Posts: 1,558
|
Good job Richard. I am envious of those with the Series 60 Jakes. The jakes on our 8V92's just don't have the braking power that yours do. I don't have to worry about mine latching. I need all the braking assist I can get.
__________________
|
|
|
02-08-2010, 03:18 PM
|
#3
|
Senior Member
Join Date: Feb 2008
Location: Riverside, California
Posts: 1,543
|
Same here, Michael......in town I leave the Jake on all the time....need the extra braking sometimes, and don't want to have to remember to flip the switch. Richard, that write up is very impressive, and just what I would expect from you.
|
|
|
02-08-2010, 03:45 PM
|
#4
|
Senior Member
Join Date: Oct 2007
Location: Huntington WV
Posts: 1,041
|
"need the extra braking sometimes, and don't want to have to remember to flip the switch"
That is exactly why I rewired the circuit. Sometimes I wanted (needed) all the help I could get, and in a panic, I didn't want to be fumbling for the switch. On the other hand, I could not modulate the accelerator well enough to keep the jakes from coming on while interstate cruising, or worse yet, the cruise control and jakes would get into a fight on the downhills.
The circuit modification activates the jakes ANYTIME I press the brake pedal.
I didn't like the possibility of me cruising the interstate at warp factor four, running without the jakes, and topping the hill into a traffic snarl or worse. Not a situation where I would have time to hunt for the on/off switch.
The brakeswitch folks recommend a wiring circuit that uses the brake pedal to "latch" the jakes. That's great, cause with that circuit, you get the jakes coming on with the brake pedal, and staying on without the brake pedal depressed for mountain pass descending. With that setup you have to press the accelerator to get the jakes to release.
It just seemed much more intuitive to me to have the jakes come on and go off with the brake pedal. I added the bypass circuit for the rare mountain pass descent. We don't have too many of those in Tejas.
__________________
Richard Rhonda Ty and Alex Entrekin
1995 Newell # 390 DD Series 60, Allison World Trans
Subaru Outback toad
CoMotion Tandem
Often wrong, but seldom in doubt
Rhonda's chronicle https://wersquared.wordpress.com/
|
|
|
02-08-2010, 05:26 PM
|
#5
|
Senior Member
Join Date: Apr 2007
Location: Minnesota
Posts: 326
|
I'm like Clarke, leave it on all of time and love the sound of it going on. Ive'e be told by my bus mechanic friend to leave it on all of the time and the only time I turn it off is when I come to a town that does not allow them.
Michael, I do a lot of mountain driving and am really satisfiessd with the hold back that I get from mine. My friend did work on mine and did some adjusting on it a few years ago but I can't tell you what he or how he did it.
__________________
Wally and Phyllis
1988 Newell Coach #163
40' with tag 8V92
|
|
|
02-08-2010, 05:57 PM
|
#6
|
Senior Member
Join Date: Feb 2008
Location: Riverside, California
Posts: 1,543
|
Love the sound of the Jake! I remember as a young lad staying in roadside motels on our travels to Idaho to visit my grandparents, and hearing the sound of the Jake brakes all night long as trucks came through town.....to me that sound is associated with being on the road, which is where I love to be. Fortunately, like Wally, my Jake works well with my cruise control, and there is no battle between the two. When I go to zero throttle the Jake comes on, and when the cruise control is engaged it (the Jake) is off.
|
|
|
02-10-2010, 01:06 AM
|
#7
|
Member
Join Date: Nov 2007
Posts: 73
|
our 87 had only one switch on/off i found that it was only for the left bank so i ran two wires and installed another switch for low/high (left/left & right) what a difference
__________________
87 Newell Tag 40'-8v92TA-HT740 #139
|
|
|
07-21-2011, 05:49 PM
|
#8
|
Member
Join Date: Feb 2006
Location: Yuma, AZ
Posts: 45
|
Scanning some of these older posts. The above caught my eye. Anyone else with a 8V92 discover only one bank active with the jake brake. I am going to check mine out as they are pretty weak.
__________________
Gary Carter
'93 43.5' #318
|
|
|
07-21-2011, 06:44 PM
|
#9
|
Senior Member
Join Date: Sep 2008
Location: Thibodaux, LA
Posts: 1,221
|
OK, how do I tell?
Where would the wires on the engine be located?
Thanks
|
|
|
07-21-2011, 08:28 PM
|
#10
|
Member
Join Date: Nov 2007
Posts: 73
|
Our is a non ddec the wires are located on the back side of the valve covers one on each side have to use a mirror on a stick to see them. one is dark blue-black? other is yellow if you dont have a three way (low-off-high) or dual switch (on -off / low-high) even with ddec you are probably running only low according to the wiring diagram. having it set to run only high would be dangerous in bad weather. Brian
__________________
__________________
87 Newell Tag 40'-8v92TA-HT740 #139
|
|
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Threads |
|
|