engine exhaust brake

actionron · 06-15-2015, 09:47 AM

Hello all,

i have a 2004 Journey with a 330 . Just bought it not too long ago and will be going over some mountains soon. My question is , do i leave the engine exhaust brake on all the time or only when needed going downhill to help slow coach??

Thanks
Ron

bgholson · 06-15-2015, 09:55 AM

Do whatever you are comfortable with. As soon as you take your foot off the accelerator the brake engages. This bothers me unless I am going downhill so I switch it off and on as needed. Some like using it in town traffic. My cruise control doesn't work when the brake switch is on

Skip426 · 06-15-2015, 10:05 AM

You will have to test your coaches interaction between the exhaust brake and the cruise control, as many chassis like my Freightliner the exhaust brake can be left turned on when the cruise is in use.
BUT;

in rolling hills the exhaust brake will engage any time the coach starts to coast, cutting the cruise off, because the brake lights come on with the exhaust brake, then you have to accelerate and re-set the cruise or hit resume . Some members have installed a foot operated switch in the area of the drivers left foot to control the exhaust brake , so they don't have to go for the dash switch every time.

EDIT: I will add , remember to slow to your control speed for the start of the decent; at the summit; I prefer 45MPH, it is much easier to increase speed than slow after you start downhill, particularly on the steeper grades.
Watch your RPM, when using the exhaust brake , as the transmission WILL shift to a higher gear if the engines RPM limit is reached, should be about 2700, on your Cat. So use the service brakes to keep RPM to keep between 2000 and 2500 the RPM where the brake has the most effect.

MaverickBBD · 06-15-2015, 10:06 AM

You will soon find out what works best for you. For me it depends on % and length of grade. If the sign says 7% next 6 1/2 miles I would probably turn mine on and leave it on. There most likely be additional service brake application to get to desired speed then back on exhaust. Remember to take you Alison out of economy mode. Switch to your engine display on your Trip Check and remember the rule. Never go down a hill faster then you went up it. What I like about exhaust is it is telling my transmission 2nd gear is desired. Tranny is saying I will work my way there when it is safe to do so. That way I am not manually shifting down. If you want to switch it off on long downgrades, like pressure on accel. will do it.

Luckiest Dreamer · 06-15-2015, 11:31 AM

I have a tendency to leave mine on once I turn it on. (A bit like out of sight out of mind) However, whenever it engages the brake light does as well. On One trip I ran in rain all day and by the end of the day my toads battery was totaly discharged to the degree that it needed replaced. It may be interesting to see what happens now that my latest install was the invisabrake. It is supposed to have the ability to charge the battery as I drive. Yet at the same time the brakes are activated by the coaches brake lights.

Skip426 · 06-15-2015, 11:39 AM

Larry B; if you want to isolate the invisibrake application from the exhaust brake operation of the brake lights, so it will only operate with the service brake , you can do so with the installation of a diode near the brake light switches. I have a diagram drawn up if you would like it.

Second thought , I did the diagram for a trailer brake controller, I'll have to read up on the Invisibrake to see if it would work.

RE-EDIT: My diode system wouldn't work for the Invisibrake , because it is activated by the operation of the brake lights in the toad and not the operation of the brake light switches in the coach. When I was researching aux , brake systems , it was one of the ones I discounted because the toad brakes would be on with the exhaust brake.

Gormleys · 06-17-2015, 07:21 AM

This is a great discussion on exhaust braking. Is the comment about turning the Allison off of Economy documented anywhere in the Winnie supplied documentation? It makes sense, but I don't remember seeing that mentioned anywhere else?

Luckiest Dreamer · 06-17-2015, 09:29 AM

Quote:

Originally Posted by Gormleys

This is a great discussion on exhaust braking. Is the comment about turning the Allison off of Economy documented anywhere in the Winnie supplied documentation? It makes sense, but I don't remember seeing that mentioned anywhere else?

I suspect that has been addressed as well and you my find it running a search. My economy setting turns off with the key and I tend to forget it once back on the road. However, I have not been able to tell any difference in fuel mileage, only in a change of shift points. And how that effects me has a tendency to go along with my mood. Or maybe I should say on the terrain and my need for speed!

Skip426 · 06-17-2015, 09:54 AM

I'm with Larry on this, trans control program , re-sets to power with every start up, and I have a tendency to forget to scroll to economy.

If I do remember, I usually go back to the power setting at the base of a long climb, and will manually select a lower gear to prevent an up-shift/ down shift cycle should I have to lift, off the throttle , on an up-hill corner.
I don't have any documentation on the , trans program for downshifting , when the exhaust brake is active, but I think that program is independent of the mode setting.

MaverickBBD · 06-17-2015, 11:35 AM

Economy mode info. from Alison manual. Exhaust brake mode from either Freightliner or WBGO manual (maybe even Cat). You remember the day when you read them cover to cover.

Ramzfan · 06-23-2015, 07:44 AM

I have found that the exhaust brake works well when going through a city...it saves a lot of wear & tear on your coach brakes. Brakes on a large motorhome can be very expensive to replace. One thing you need to remember about exhaust brakes though, is that they too need maintenance. There is a special oil that needs to be applied once in a while to keep the brake working smoothly.