Jake Brake in Cruise Control?

[OldForester]

I have a question for the group. When I read the owner's manuals it says to take the Jake Brake off when in cruise control. I am used to driving with the Jake on when not in cruise control, usually in "low", but if in traffic or a steep downhill, in "high". That means I turn the Jake off when I put it cruise control. Of course, when I'm going down a big hill in cruise on the freeway, that means I must turn the Jake on when I step on the brake or disable the cruise control, to keep the speed in line.

So, do others take the Jake off when on cruise and put it back on when not, or just leave it on when on cruise (doesn't seem to do anything in cruise anyway)?

Appreciate your answers on this.

[OldForester]

I have a question for the group. When I read the owner's manuals it says to take the Jake Brake off when in cruise control. I am used to driving with the Jake on when not in cruise control, usually in "low", but if in traffic or a steep downhill, in "high". That means I turn the Jake off when I put it cruise control. Of course, when I'm going down a big hill in cruise on the freeway, that means I must turn the Jake on when I step on the brake or disable the cruise control, to keep the speed in line.

So, do others take the Jake off when on cruise and put it back on when not, or just leave it on when on cruise (doesn't seem to do anything in cruise anyway)?

Appreciate your answers on this.

[Wayne R]

OldForester,

I tend to turn my Jake brake on only when I want to use it. I find it is very annoying to have the Jake come on when ever the coach is coasting while in cruise control. I believe it cancels cruise when the Jake comes on. I will have to check it next time we take a trip.

I do intend to check and find out if the transmission can be reprogrammed to only down shift to 5th when the Jake comes on so that the engine doesn't over speed at 60 MPH. I would still be able to manually downshift if more braking was required.

[Wil Rathke]

I agree with Wayne and only use the Jake as needed. However, if the Jake switch is on in either position it will not operate when the cruise is on. If the brake is applied to disable the cruise, the Jake will then activate.

I have found that the transmission will never down shift to a gear which will result in engine RPM in excess of about 2500 RPM. With a speed of 65 - 70 it will downshift to 5th and then 4th as the speed decreases. I will also downshift manually to 3rd or 2nd as more brakeing is needed for a complete stop.

[Wayne R]

Wil is right, I probably was annoyed when I tapped the brake while in cruise control and the Jake brake came on.

When I turn my Jake brake on and release the accelerator pedal the Silver Leaf monitor shows 4th selected and the transmission actually in 4th. It displays 4, 6 while it is waiting for the coach to slow enough to engage the Jake it then shows 4,4.

Sometime during the 04-05 model year Cummins went from a wired 2 stage Jake to an ECU controlled Jake. At first we only had the high setting in either switch position. A software update in January 06 added the low setting. That may explain why some coaches operate differently. Or I may be just misinformed.

[Indio]

Wayne..........

The MH3000 can be re-programed to down shift to the 5th gear. Any Allison shop with a computer can do it.

I find it much less annoying especially in traffic to not have to each time I take my foot off the gas to regain the RPM loss.

Walt

[Nick Escamilla]

I recently added a 2 pole relay to operate and turn the Jake brake on only when i apply the brakes. If I don't step on the brake, Jake doesn't go on and I coast. I leave the Jake on high. I had to a a micro switch to the accelerator pedal, this allows me to turn off the Jake if I accelerate. If you are interested in adding this simple circuit contact me. It works great and you use a lot less braking.

Nick

[OldForester]

Nick,

I would be interested in what you did. I find that I use the Jake on high most of the time because I don't want to use my brakes in traffic, and I would like for the Jack to come on in high when I step on the brake to get off cruise control, and stay off the rest of the time. The exception would be when I want to keep the Jake on low for more lightly rolling terrain.

So if you could share this setup with us I for one, would be most appreciative.

So how you addeed this relay

[EngineerMike]

Nick- That is a heckuva <span class="ev_code_BLUE">cool</span> tweak.

You should sell kits. If you don't want to start such a biz, post the part #'s, where purchased, and description of what hooks up where.
Mike

[chris cross]

Nick-- what a great idea. I'll second EM and ask that you post everything needed.

[EngineerMike]

Add an over-ride switch for a safety in case the micro-switch foozles up, and we can call it the <span class="ev_code_BLUE">Nake-Brake</span>

[Nick Escamilla]

If your interested in the circuit I'll scan it to and electronic file so I can email to anyone who wants it. Adding a safety switch is not necessary, if the accelerator switch freezes, just turn of the Jake Brake switch and when you accelerate the Jake brake goes off naturally. All I'm doing is interrupting the common on the Jake switch. I'm not tapping into any electronics and certainly not dangerous.

You need to add 2 diode to protect from feedback.
One 2 pole relay, both normally open contacts.
One micro switch and manufacture a bracket to hold micro switch to accelerator arm.
Wire and connectors.

[rmmpe]

No Speakee Engrish--------send picture.
Prease.

[APEXMAN]

I would like a one