Exhaust Brake Switch. Leave it on or off?

[Gordon Dewald]

Leave ours off except when I intend to use it. IMO will not help in a panic stop as the brakes can lock the wheels. Driving in stop and go traffic I like to be able to coast.

Most towns have bylaws that make it an offence to use engine brakes in town.

[djbmsu]

Cummins will reprogram the brake to come on automatically when you apply the brakes and then off when you excellerate so you dont need to do anything. Helps alot when in slow moving traffic. This will also allow you to still manually turn it on and off.
On some RV's when you turn on the exhaust brake you are also turning on your brake lights on the RV and your toad as well.

[Crasher]

I have always left it on in the low position. I switch into high when descending steeper hills. I don't have that crystal ball that tells me when it will be needed, so it is always on except on slippery or wet roads. I don't worry about it's use in town as the muffler eliminates any offensive noise. Yes, it comes on when the cruise is cancelled or the brake is touched, but goes off as soon as I tap the accelerator. It's very easy to manage without turning it off.

[JFXG]

I use my exhaust brake regularly and often, but I don't leave it on. I will decide when to use it, not whoever designed the activation sensor.

[MRUSA14]

Originally Posted by Gordon Dewald

Leave ours off except when I intend to use it. IMO will not help in a panic stop as the brakes can lock the wheels.

Not likely unless you have an older coach. I think all the DP's made in the past 10 years or more have ABS which will not allow the wheels to lock up.

[MRUSA14]

When I attended a Spartan Chassis owners' class, they recommended not leaving the Jake Brake on. They said that the brakes would get too little use and be subject to glazing. Regular braking keeps the brake shoes/pads in good shape. They also said that you could not wear your brake pads out unless you drive 150,000 miles or more, so why save them?

[TMan59]

Only turn mine on when I need it.

[Dr4Film]

Another Exhaust Brake Switch ON or Off Thread.

Chevy - Ford ??

My exhaust brake switch is on 24/7/365. It never gets turned off unless for service or maintenance.

Dr4Film ----- Richard

[Dr4Film]

Originally Posted by gatorcq

The question you have to asked yourself: Do you have a Jake Brake, Exhaust Brake, Pacbrake?

One would assume that he has an Exhaust Brake since that's how he labeled the title of the thread.

However, there are way too many people who don't know the difference between an Exhaust Brake and an Engine Brake.

For those that don't Google is your friend.

Dr4Film ----- Richard

[Dutch Star Don]

There are a bunch of topics all wrapped up in one here. How you use your engine brake or exhaust brake depends on you and how yours is set up.

Cruise Control - My previous coach (2005 Monaco Diplomat) would not allow you to use the cruise control while the exhaust brake switch was "ON". Back then, there was an older gentleman named Homer who invented and sold the "Brake Switch". The "Brake Switch" was wired into your exhaust brake and taillights and allowed your cruise control to engage while the exhaust brake switch was "ON". This was a great product both for braking safety and ease of cruise use. Several years later, the new coaches were programmed to do the same thing the "Brake Switch" did. Last time I talked to Homer, a couple of years ago, he only had a few switches left and wasn't going make or sell them anymore.

Braking - Obviously, we all use the engine or exhaust brake when descending grades. Both models will downshift the Allison as the coach slows.

Traffic - Personally, I don't use mine in traffic because it can be annoying. There is also an argument that constantly using the exhaust/engine brake at low speeds can cause your brakes to glaze from lack of use/light use. this can cause them to lose some efficiency and possibly squeal.

Programming - I didn't know until I had my previous coach checked for a computer issue, that you can change the programming via the ECM on how your exhaust brake (unknown about engine brake) reacts to braking and throttle. Before I changed mine, my exhaust brake immediately engaged when I let off of the throttle. After the change, (toggling of a computer setting in the ECM) my exhaust brake would only engage when I stepped on the brake. A touch of the throttle would make it disengage. I found this set up allowed me to coast in rolling hills, rather than apply the exhaust brake the moment I let off the throttle. This made for a much more comfortable drive.

Not all coaches can change this programming. I believe it became programmable sometime in 2004 -2005.

Most new coaches already incorporate this feature and the cruise control works while the switch is "ON". On my current coach, my engine brake, while switched on, will actually engage/disengage while in cruise control to maintain my cruise speed. So.....coaches and programming have come a long way.

Typically, you're descending a grade or slowing down when your exhaust brake/engine brake is on, so your fuel mileage actually increases since you're coasting.

Side Note: I run the SilverLeaf VMSpc program and can watch my intake manifold temps (the Cummins computer doesn't look at or see exhaust temps as part of it's monitoring, so I watch intake manifold temps) I was surprised to see that temps can climb quite a bit when the exhaust brake is engaged. Just something to think about if you exit right after a long downhill.

[Mr_D]

Originally Posted by gatorcq

The question you have to asked yourself: Do you have a Jake Brake, Exhaust Brake, Pacbrake?

Pacbrake is an exhaust brake by a trade name

[Mr_D]

Originally Posted by Gordon Dewald

Most towns have bylaws that make it an offense to use engine brakes in town.

But that's only for unmuffled ones and the new ones are muffled so no problem.

[mel s]

Originally Posted by slowmachine

brakeswitch.com looks like a dead link to me.

slowmachine
Homer, the former maker/seller of the "BrakeSwitch" no longer offers them.
IMO that's to bad 'cause they are a wonderful device.

However, on some Cat powered coaches the "cruise control perimeter", (in the ECM), can be electronically programed, (at any Cat service shop), into "coast mode"...(which results in the same excellent exhaust brake control as adding a Brakeswitch does/did).

BTW, I'm not sure about Cummins powered coaches, (ask at a Cummins shop).

Mel
'96 Safrai, 3126 Cat, Allison M3060 transmission, PacBrake and a BrakeSwitch.

[Dr4Film]

Mel,

Cummins offers a programming mode called "Latching Mode" which will take care of that situation.

My Cummins ISC 350 had been programmed by the original owners. I was one of the lucky ones.

Unfortunately some Cummins shops when asked about programming the "Latching Mode", they will have a blank stare on their face.

Dr4Film ----- Richard