How important is the exhaust brake?

On our gas rigs was always told gear down, we did the C
anadian and US Rockies with a 32 gas with no problems, also had an engine brake on our Journey, it was great but no better than gearing down a gasser.

On my International diesel, I don't have an exhaust brake, but my Allison transmission does have a Williams hydraulic fan retarder mounted to the back of the transmission that does the same thing for the tranny as an exhaust brake does for an engine. The retarder works awesome, about as well as the giant air service brakes. The only thing is I have to be careful not to overheat the tranny from using the retarder too much. I keep a close eye on the tranny temp gauge when using the retarder alot. It works so good that would not want to have the same truck without the retarder.

I installed one on my '97 Ram CTD and loved it. I replaced the '97 with an '07 Ram CTD and really REALLY miss it. No scary events running around the Rockies, but I sure miss it.

I've RV'ed my entire life, my parents own a cat 300 coach now and I just bought my first diesel 3500. We have hauled our rigs every where with gasoline units, now much in the same way we look back at towing the tent trailer with the Mustang, and TT with a half tone, every step up we've asked ourselves how we lived without it. Now that I'm 1tonne towing with a diesel and exhaust brake, I don't know how I made it through the mountains with the 07 6 liter 2500hd.

If you've never had it, you won't miss it. I for one see a huge value in the EB, in that among other things, I won't ever have to worry about gassing off my brakes again.

j-d wrote:
In a Class C, Diesel comes with two trade-offs. Or you can call them penalties:

1. At least in Ford, the Van/Class C version of the current pickup truck diesel is NOT the same. It is de-tuned, because the engine compartment doesn't allow the space for cooling the pickup version's higher output. Don't buy a diesel Class C based on how well a diesel pickup runs out.

2. Class C is already short on carrying capacity, and the significant added weight of the diesel comes right out of the weight you can carry.

I agree with j-d. The diesel installed in the E350 and E450 had serious compromises to make it work. Diesels in the F-Series and class-A's are A-Okay.

j-d, I do wonder if the extra weight up front with a heavy diesel engine, would actually benefit the E350/E450, acting as a counter-weight to a typically floating front end, floating from so much rear weight. As with many others, our 2007 E350-V10 gas front axle required off-set bushings for a proper wheel alignment.

An exhaust brake is not needed with a gas engine.

Diesels use exhaust brakes, because diesels don't have good engine braking by nature. This is due to the fact that the intake air plenum of a diesel is always open. There's no throttle butterfly that closes off the intake on a diesel, like there is on a gas engine.

On a gas engine, all you need to have good engine braking is adequately low ratio gearing in the axle, and use the lower gears in the transmission to control the vehicle's speed on downgrades.

If you have an automatic tranny, you need one that stays locked in each gear, particularly the lower gears, rather than one that freewheels, disconnecting the engine from the axle when decelerating.

This was a major pet peave of mine with the Ford E4OD auto tranny in my 7.3 diesel F350. The tranny would freewheel, removing what little engine braking the diesel could provide. The truck was a nightmare to go down long steep grades with a heavy trailer.

I had the tranny completely rebuilt, modified and reprogrammed, to provide maximum engine braking, in all gears at, all times. That was a major improvement in safety. I also had the engine's computer reprogrammed, to close the turbo valve whenever the throttle was let off, to act as a sort of exhaust brake.

On my 5.8 gas engine F350, once I changed the axle gearing from 3.55 to 4.56, with the C6 auto tranny, I had all the engine braking I needed, to not have to use the brakes to maintain speed down most grades while loaded heavy and pulling a trailer too. No need for an exhaust brake with the gas engine.

Gearing is your friend. The lower, the better. :)

BillHoughton wrote:
Out here on the coast, exhaust brakes are prohibited in many areas (mainly near towns). Anyone who's ever lived/camped near a hilly highway knows why.

An Exhaust Brake is not the same thing as a Engine Brake/Jake Brake. They are not banned by the above sign.

Out here on the coast, exhaust brakes are prohibited in many areas (mainly near towns). Anyone who's ever lived/camped near a hilly highway knows why.

Ignoring type of rig, if you are hauling a ton of weight in the mountains, an engine or exhaust brake is essential, in my opinion. As DutchmenSport said, they are pretty great even on the flats.

Not a Class-C owner here, but my Chevy truck has Exhaust Brakes. First truck I've ever used them with. Indiana is pretty much flat, but does have it's hills, especially Southern Indiana, and have made several trips to Florida now over the hills of Virginia, NC, Georgia, and so on.

I will say, I love it! It's not so noticeable when NOT towing, but when towing it really saves on using brakes. Of course, the less you push on the brakes, the less wear there is on the brake pads and rotors. The Exhaust Brake will keep the engine from racing when going down hill. It will also keep the gears from shifting up. It will also help hold the speed steady. When you do need to push the brakes, it will slow the vehicle down, causing a down-shift and then the speed will hold in the gear, .... meaning ... you don't have to push the brakes so hard.

Now, granted, you can do the same thing by simply down-shifting manually, but that means applying the brakes enough to slow the vehicle down so you can get it to down-shift to the next lower gear. Exhaust brake will kind of do the same thing.

So, in the end, it's really a nice feature, I think something copied from the big rig 18 wheelers. I love mine, and when I actually have to use it, it's great! But the other 90% of the time, it never engages. But when towing, I automatically flip on Tow Mode and Exhaust brake. On the interstates I can flip on cruise and never have to touch any floor peddles, it holds the speed and brakes too. Sweet ride when it does that!

It's all a matter of what you really want. But, I promise, once you've had it, you'll never want to give it up, even on flat land driving.