Community Forums

Pexring · 10-18-2015, 08:26 AM

I used the exhaust break for the first time this weekend in my 2000 Newmar that I bought over the summer. I asked the previous owner if he had ever used the exhaust break and he said no, didn't know what it was. We live in a very flat area so you have to drive aways to encounter any hills.

This weekend I encountered a town along the river and decided to try the exhaust break while driving up and down the river breaks. At first I was afraid to flip the switch as it's probably been years since it's been flipped and I was paranoid something would break or lock-up. Luckily nothing like that didn't happen.

My questions. Do you leave your exhaust break on all the time, or just when driving hills? Should I be shutting it off when driving in a city with a bunch of stop lights? Should I shut it off when not driving hills?

Trekgrr · 10-18-2015, 08:37 AM

Quote:

Originally Posted by Pexring

I used the exhaust break for the first time this weekend in my 2000 Newmar that I bought over the summer. I asked the previous owner if he had ever used the exhaust break and he said no, didn't know what it was. We live in a very flat area so you have to drive aways to encounter any hills.

This weekend I encountered a town along the river and decided to try the exhaust break while driving up and down the river breaks. At first I was afraid to flip the switch as it's probably been years since it's been flipped and I was paranoid something would break or lock-up. Luckily nothing like that didn't happen.

My questions. Do you leave your exhaust break on all the time, or just when driving hills? Should I be shutting it off when driving in a city with a bunch of stop lights? Should I shut it off when not driving hills?

It is up to you. when I had a coach with an exhaust break I only had it on while on the interstate, or hills. Mine would come on with the Brakes on the unit or when I let off the accelerator. I would usually have it in the Brake mode.

docj · 10-18-2015, 09:07 AM

Quote:

Originally Posted by Pexring

My questions. Do you leave your exhaust break on all the time, or just when driving hills? Should I be shutting it off when driving in a city with a bunch of stop lights? Should I shut it off when not driving hills?

Use the exhaust brake whenever you need additional braking assistance. I have a compression brake on my MH, which is a bit more powerful than an exhaust brake, and I use it:

When going down steep hills
When driving on rolling terrain (up and down hills)
When in stop and go driving (reduces brake usage)
When approaching an exit on the interstate that I intend to exit at
etc, etc

There's no right or wrong usage except for the caution not to use it in slippery conditions since only the rear wheels are being braked and skids can occur. Some drivers leave them on all the time, the only downside of that is that you lose the ability to "coast" so you use a bit more fuel.

FreedomDream · 10-18-2015, 09:16 AM

I leave mine on ALL THE TIME for the reasons given above. Stopping a 32,000 vehicle doesn't just happen and you may not have time to think about throwing the switch when you really need it quick.

It doesn't hurt to leave it on all the time.

jacwjames · 10-18-2015, 09:19 AM

I have an exhaust brake and use it anytime I am slowing down to save the brakes but I do not leave it on. My switch is located on the drivers side dash panel in a position that I can identify the switch without even looking down.

The few times that I accidently left it on I noticed a jerking motion as I let up off the accelerator.

I know some people who leave it on all the time so I guess it's up to you as to what you want to do.

Also, I would buy some Superlube and lubricate the brake,
Maintenance | Pacbrake

I bought a small bottle of lubricant and do it once a year.

t55watson · 10-18-2015, 09:32 AM

If I leave it on and have the cruise control on they act against each other on a down hill grade. The cruise lets off and the brake turns on, as the speed decreases the cruise comes on and brake turns off. So it feels bad. brake cruise brake cruisebrakecruise. So if I want the brake on a down hill I have to kill the cruise then when past the hill resume the cruise and turn brake off.

Skip426 · 10-18-2015, 09:36 AM

Some chassis , will override cruise control operation when the exhaust brake switch is turned on, others ; like mine ; the cruise can be set but the exhaust brake will activate as soon the coach starts coasting on the slightest downhill, then the exhaust brake has to be switched off and the cruise re-set to resume speed.

As docj says there is no right or wrong for the brake use, just what you're comfortable with for your driving style.
What is important to remember is; the brake is most effective at high engine RPM, that is why it's operation is tied in with a transmission gear down program. If your travelling at a speed where the transmission will not gear down to prevent over-reving the motor ( 65 MPH+) the brake will not help slow the coach. For best operation on downhills I slow to 50 MPH at the summit.
Then on longer downhills, watch the tach , to keep RPM between 2,000 ( below the trans will gear down) and 2,650 ( over and the trans will shift up ) by applying the service brakes.
NOTE: These RPM numbers are for my Caterpillar engine, with a Cummins they will probably be different.

Pexring · 10-18-2015, 09:57 AM

Thanks for bringing up comments about using the air break while the cruise is on. I meant to include a question about that in my opening post.

Pexring · 10-18-2015, 10:01 AM

Jacwjames - great link to lubricating the air break. Now where do I find it. Under the hood or do I crawl under?

alpha99 · 10-18-2015, 11:44 AM

When I first got mine left the exhaust BRAKE on the entire 1,000 mile trip after picking it up and noticed the fuel mileage was considerably worse than when I just use it selectively. Everytime I took my foot off the gas the engine was braking, instead of coasting.

Now I use it when going downhill or significantly braking, otherwise it is off and fuel mileage is great. I can reach the exhaust BRAKE switch as quickly as I can the BRAKE pedal with my foot.

Cheers!

FIRE UP · 10-18-2015, 12:15 PM

Quote:

Originally Posted by Pexring

Thanks for bringing up comments about using the air break while the cruise is on. I meant to include a question about that in my opening post.

Pexring,
First off, it's "Exhaust Brake", not "Air Break". It's not a big deal, we know what you're talking about here and now, but if you have a question on it later, and you use that term, some folks might get confused. As for using it, it's been pretty much explained on how and when you might use yours.

As has been stated, it's one of those things that, you just simply play with, in various situations, to develop a use procedure that you feel comfortable with.

Some folks (guys) get annoyed at it's factory programming especially when it comes on, each and every time you let off the throttle and the switch in in the "ON" position. So, they do a few things to alter it's operation.

1. Have the computer reprogrammed so the exhaust brake only activates when the brake pedal is touched, not when the throttle is let off. Many like the option of being able to coast when letting off the throttle but, still have the switch in the ON position.

2. Put a switch on the floor, activated by a foot, that will activate the E/Brake.

Just play with it, at various speeds, and slowing down for off ramps, long grades in or near towns and all that. You'll figure it out.
Scott

1bigmess · 10-18-2015, 12:29 PM

Please don't use your exhaust brake driving around in town off of the highway, or near developed areas of homes. In rural areas, folks usually don't mind much, but using it in town is a little rude, and in most places unnecessary.

Would you want to be sleeping and someone hit the exhaust brake near your bedroom window?

If one needs the exhaust brake near 100% of the time to stop safely, you're driving too fast, following too close, and/or not paying enough attention to what's going on. If your brakes alone are not enough to stop your rig safely, you are likely the problem, not your brakes. Know the limits of your own abilities, the rig you're driving, and stay within those limits.

docj · 10-18-2015, 01:14 PM

Quote:

Originally Posted by 1bigmess

Please don't use your exhaust brake driving around in town off of the highway, or near developed areas of homes. In rural areas, folks usually don't mind much, but using it in town is a little rude, and in most places unnecessary.

With all due respect this is a misconception shared by lots of people because for years they've heard the roar of dumptrucks with unmuffled Jake (compression) brakes. My highly muffled Jake hardly makes any more noise than does my diesel itself; an inexperienced observer wouldn't even notice the difference. Many towns that have engine brake ordinances nuance them so they read "unmuffled engine brakes" prohibited.

As for the OP, his exhaust brake doesn't make the same sound as a compression brake, anyway. So your remark is not relevant to him.

1bigmess · 10-18-2015, 01:27 PM

It's not a misconception to me. Thanks for telling me I'm wrong without knowing anything about me.

As someone that used to live in a town that had a "No engine or exhaust brake use" ordinance and near a major artery where folks used their engine/exhaust brakes often, and I worked graveyard shift. The remark is relevant, to someone, but will you know who that person is? When I was trying to sleep so I could work all night, I knew who that person was: me. Is being considerate to others in the places you go or pass through such an inconvenience or safety risk?

But whatever. Even I try to justify some of the things I do by explaining that I don't do X like everyone else, but I'm still doing something that I probably should not be, or do not need to be doing.