Community Forums

T_Roy · 02-15-2022, 08:09 AM

Looks like I might have my first bad issue. On a short trip to a local campground yesterday for our first overnight stay in the coach I had an issue. I started getting a stop engine alarm immediately followed by an auxiliary brake alarm. I pulled over on the side of the interstate an everything cleared. I took off again but as soon as I let off of the accelerator it happened again. I turned the auxiliary brake off and everything cleared up and it stopped happening. It appears I have an issue with the Jake brake. I was a few miles from the campground so I came on in with the switch for the auxiliary brake turned off. It will be interesting to see if it does it again when I leave here on Thursday. If it does it looks like I will have my first extended warranty claim.

wolfe10 · 02-15-2022, 08:11 AM

You need to tell us what engine and what model year it is.

Are you able to read the diagnostic codes?

Gary.Jones · 02-15-2022, 09:00 AM

Well, first of all, this is a new set of problems that I have not read about or experienced personally before, I don't think.

Second.... there is no reason at all to have you Jake break turned on all the time. In fact, IMO, that is not what anyone should be doing. The Jake is there to help relieve your need to brake heavily on long steep down hills descents. That is one of the only two times my Jake is ever on. The other time is a fast slowdown on an interstate exit which has a sharp turn immediately after you enter the off ramp. Otherwise, my jake should be off. Your normal service brakes are capable and designed for slowing and stopping your coach in 98% of the places you need to use brakes. They don't need help. So, problem #1, is leave the jake off until you really need it.

Now, tell us more about the errors and problem you are having. As Wolfe asks, what year and model of coach do you have. Then, what specific error or warning are you getting On the dash or elsewhere.

I have never seen any message that refers to an "auxiliary brake".
Your profile says you are a new owner of a 2015 Cornerstone on your first trip. That should be a Cummins 600 or 605 engine.

If not already done, get on the phone with Spartan and lay out the problem in detail to them and see what they tell you. Also, keep us up to date on what they are telling you so we all learn.

Gary

dizcom · 02-15-2022, 11:02 AM

Quote:

Originally Posted by Gary.Jones

Well, first of all, this is a new set of problems that I have not read about or experienced personally before, I don't think.

Second.... there is no reason at all to have you Jake break turned on all the time. In fact, IMO, that is not what anyone should be doing. The Jake is there to help relieve your need to brake heavily on long steep down hills descents. That is one of the only two times my Jake is ever on. The other time is a fast slowdown on an interstate exit which has a sharp turn immediately after you enter the off ramp. Otherwise, my jake should be off. Your normal service brakes are capable and designed for slowing and stopping your coach in 98% of the places you need to use brakes. They don't need help. So, problem #1, is leave the jake off until you really need it.

Now, tell us more about the errors and problem you are having. As Wolfe asks, what year and model of coach do you have. Then, what specific error or warning are you getting On the dash or elsewhere.

I have never seen any message that refers to an "auxiliary brake".
Your profile says you are a new owner of a 2015 Cornerstone on your first trip. That should be a Cummins 600 or 605 engine.

If not already done, get on the phone with Spartan and lay out the problem in detail to them and see what they tell you. Also, keep us up to date on what they are telling you so we all learn.

Gary

It doesn't hurt at all to leave the jake on all the time on a newer rig. The only time it really needs to be off is when you are in slippery conditions. Otherwise, it doesn't hurt a thing. We always talk about it here as if it's only for going down a hill, but I find it useful in stop and go traffic and when on surface streets with high speed limits. Mine is on more than it's off these days. Your manual might say different, but mine says it's fine to leave it on always.

Gary.Jones · 02-15-2022, 11:42 AM

Dizcom

Well, you have your opinion, and I have mine.

Leaving the Jake engaged all the times will turn your "ride" all the time into a jerky mess. Every time you take your foot off of the "gas" peddle, going faster than about 20 mph, will cause your transmission to down-shift to second gear and actually force a downshift of at least one gear. There is a significant jerk in your motion when that occurs. Now, you apply the diesel again and your transmission now upshifts again to the proper gearing given your speed and torgue... Another jerk, and another needless shift of the transmission.

The only way to avoid all the jerkiness is to "feather" the diesel foot feed so that you sort of are always not coasting and you are always slightly accelerating. Make sense? Doesn't to me.

What possible justification is there for all that shifting and jerking? What justifies the jake kicking-in repeatedly in normal stop and go traffic of greater speed than 20 mph?

Up and down shifting repeatedly. What the heck are your regular service brakes designed for other than "normal" stopping and slowing? They will last for hundreds of thousand miles. Can't remember reading of any owner of an Entegra coach who has needed new brake shoes.

If you like the jerkiness of your travel, then by all means keep the jake always engaged, or smooth out your ride and turn it off. Its doing nothing that is meaningful or good on your coach if "always on"

Gary

dizcom · 02-15-2022, 12:49 PM

Quote:

Originally Posted by Gary.Jones

Dizcom

Well, you have your opinion, and I have mine.

Leaving the Jake engaged all the times will turn your "ride" all the time into a jerky mess. Every time you take your foot off of the "gas" peddle, going faster than about 20 mph, will cause your transmission to down-shift to second gear and actually force a downshift of at least one gear. There is a significant jerk in your motion when that occurs. Now, you apply the diesel again and your transmission now upshifts again to the proper gearing given your speed and torgue... Another jerk, and another needless shift of the transmission.

The only way to avoid all the jerkiness is to "feather" the diesel foot feed so that you sort of are always not coasting and you are always slightly accelerating. Make sense? Doesn't to me.

What possible justification is there for all that shifting and jerking? What justifies the jake kicking-in repeatedly in normal stop and go traffic of greater speed than 20 mph?

Up and down shifting repeatedly. What the heck are your regular service brakes designed for other than "normal" stopping and slowing? They will last for hundreds of thousand miles. Can't remember reading of any owner of an Entegra coach who has needed new brake shoes.

If you like the jerkiness of your travel, then by all means keep the jake always engaged, or smooth out your ride and turn it off. Its doing nothing that is meaningful or good on your coach if "always on"

Gary

The manual isn't my opinion. You said it was a problem to not leave the jake off. It isn't. That's a fact, not my opinion. I also suggested the OP check his manual to see if it says any different. I don't know anyone who has the ride issues you described when using their jake. You might want to get that looked at.

T_Roy · 02-15-2022, 01:12 PM

It is a Cummins 600. No warning codes or fault codes are set in then dash. I spoke with Spartan and they suggested bringing it to Cummins to have it plugged in. The only thing I saw when it was happening was the words stop engine would appear in the dash then that would go away and followed immediately by the words auxiliary brake. However when I turned the jake brake off it did not happen again as long as the jake brake switch was off. I will be leaving here on Thursday for a short trip over to LSU campus for opening weekend of baseball season. If it is still doing it after that I will figure out where to go to get it plugged in.

Max Headroom · 02-15-2022, 01:25 PM

Quote:

Originally Posted by Gary.Jones

Well, first of all, this is a new set of problems that I have not read about or experienced personally before, I don't think.

Second.... there is no reason at all to have you Jake break turned on all the time. In fact, IMO, that is not what anyone should be doing. The Jake is there to help relieve your need to brake heavily on long steep down hills descents. That is one of the only two times my Jake is ever on. The other time is a fast slowdown on an interstate exit which has a sharp turn immediately after you enter the off ramp. Otherwise, my jake should be off. Your normal service brakes are capable and designed for slowing and stopping your coach in 98% of the places you need to use brakes. They don't need help. So, problem #1, is leave the jake off until you really need it.

Now, tell us more about the errors and problem you are having. As Wolfe asks, what year and model of coach do you have. Then, what specific error or warning are you getting On the dash or elsewhere.

I have never seen any message that refers to an "auxiliary brake".
Your profile says you are a new owner of a 2015 Cornerstone on your first trip. That should be a Cummins 600 or 605 engine.

If not already done, get on the phone with Spartan and lay out the problem in detail to them and see what they tell you. Also, keep us up to date on what they are telling you so we all learn.

Gary

This is completely opposite of what my Cummins manual and chassis manaul says.
I have the M11 with a real jake, not a pac brake. It's left on all the time, and there is a foot switch to activate it. According to my manual, the proper use is to lift throttle, jake, and then use the service brake to bring the vehicle to a stop once the jake cuts out at low speed. Optionally the service brake can be used with the jake for steep deceleration such as panic braking. Otherwise 90% of braking is done with the jake. Other than holding the coach still at lights, most of my braking is done with the jake. Why wear the service brakes unnecessarily? That is the whole point of the jake.

wolfe10 · 02-15-2022, 01:26 PM

Yes, a slight "detour" to whether it is good/bad to leave the engine brake on all the time.

Can you do it-- sure?

Why wouldn't you do it:

Every time you take your foot off the throttle, you downshift and the engine brake comes on. In rolling hills, every time you crest that little hill, instead of coasting/building a little speed for the next hill, you BRAKE.

Sorry, no way could I drive that way, nor would I want to take the MPG hit associated with never coasting.

Your coach, your money, your decision.

brobox · 02-15-2022, 02:47 PM

Quote:

Originally Posted by wolfe10

Yes, a slight "detour" to whether it is good/bad to leave the engine brake on all the time.

Can you do it-- sure?

Why wouldn't you do it:

Every time you take your foot off the throttle, you downshift and the engine brake comes on. In rolling hills, every time you crest that little hill, instead of coasting/building a little speed for the next hill, you BRAKE.

Sorry, no way could I drive that way, nor would I want to take the MPG hit associated with never coasting.

Your coach, your money, your decision.

I remember one thing you said on RV Net years ago and I have never forgotten it. "Why would I want to eliminate my favorites speed.......coast by running with the Jake brake always on" Over the years that has also become my favorite speed.

wolfe10 · 02-15-2022, 02:51 PM

Ya, at the diesel maintenance seminars I presented, when someone complained about MPG, two questions:

How fast do you drive

AND

Can you coast when you let off the throttle.

PRETTY BASIC.

Again, no "have too's" in terms of engine brake setting/use (same issue for exhaust or engine compression brake) but there are penalties for deterring driving decisions to the machine.

dave&ginny · 02-15-2022, 04:17 PM

At homecoming Big Mike from Spartan advised to leave the "Jake" off unless you're in the hills. I believe he said that with the current brakes, the self adjusters aren't activated unless the brakes are used.

I have used mine in traffic and if the Jake hits at the same time as the transmission down shifts it will give a jerk. This usually wakes my sleeping wife up quickly.

J Gunter · 02-15-2022, 05:40 PM

Well on a different note you can always program the computer to not engage the jake when you let off the accelerator. When I release the accelerator coach will coast, with jake switch on, until I touch the brake pedal.

Gary.Jones · 02-15-2022, 05:58 PM

Dizcom

I suggest that you read my post again .... at no point do I say that someone should leave the jake on all the time. In fact, my whole post talked about why it would be dumb to leave it on all the time.... its unnecessary and it leads to a jerky ride. I believe that everyone except one guy who doesn't drive an Entegra coach, including a Spartan service head also advised not to use the jake routinely.

Headroom... so if I understand your description of your coach, your jake is NOT on all the time.... yes, you have it sort of turned on but you have to activate a separate footswitch to actually activate the jake. That is a completely different situation than what we have in our coaches. Ours is either on or off and if it on, then the jake kicks into operation as soon as you take your foot off of the "gas" pedal. Totally different operation than your coach, apparently.

Now my point was then, and remains now, you are free to drive your coach with as jerky a ride as you want, but it is not necessary or even advisable to do that. However, feel fee to drive however you want. I was making my comments to the OP,

Gary