How important is an exhaust/jake brake?

[denochs]

As far as claimed extra wear/stress on the turbo, hogwash! Those 80,000 pound trucks that have been using them and logging 500,000+ miles without a problem is proof of their usefulness and reliability.

My 03 has never had a brake problem. In fact, I still have the original brake shoes because of the jake brake. If you are familiar with Black Mountain on I 40 eastbound in NC, we manage to come down that hill holding back all 44,000 lbs without having to touch the service brakes.

Can't say enough about the comfort of having a backup to service brakes.

Dave

[mrblanche]

As a trucker, I like having one. However, I went cross country many times with a 350 hp engine and 80,000 gross without an exhaust brake, and I never had any major problems. As others have said, they can make your life much easier. They also add more parts in the engine that can break and have to be replaced. Yes, it happens; I had a brand new engine in about 1995 that broke a part in the jake on the first use (less than 100 miles on the truck). In the next 5,000 miles, it did over $5,000 damage to the engine before it got repaired.

[Clayobx]

Originally Posted by Ed S

I would think, not having one is like not having a tolet. Not good.

X-2 on that!

[CampDaven]

Originally Posted by Ed S

I would think, not having one is like not having a tolet. Not good.

Well not best, but still good without one. My next will have a Jake. Had 2 previous rigs. Same gear down as up. Brake jobs in both at about 70K miles. Cant smoke a brake if you dont ride it.

[wil01]

Just for the record, Jacobs make several different diesel braking systems including an exhaust brake. They all go by the nickname of "Jake Brake." Most motor homes use the Pac brake when an exhaust brake is factory installed. I have had two Pac brakes and one Jacobs. I find that the Jacobs works better than the Pac.

I suspect mh manufacturers normally use the Pac because it is cheaper.

My latest mh came without an exhaust brake. One trip in the mountains was enough for me to install a "Jake" exhaust brake.

I had a Pac on a 1996 American Eagle that would stop working at the worst times. The worst was coming down the west side of Loveland Pass on I-70. That rig had drum brake pads, and if they got too hot would fail altogether. I just stopped several times coming down that multi-mile grade to keep the brakes cool. The Pac was repaired when I got home and worked fine for the next 100,000 miles.

I will not drive a diesel mh without an exhaust brake.

[MSHappyCampers]

I can't imagine any MH of any size not having an exhaust brake!

[HHg]

You know, I got along just fine without one on my other M/H's. I even took my Serrano (Fred) over the Rockies, through the Tetons, into and through Yellowstone and back and forth through Colorado on numerous occasions. Never even blinked. BUT, now that I've had one, I sure do love it.....and believe it or not, my Patriot braking system doesn't engage near as much as it used to on my toad.

Hhg

[CampDaven]

Originally Posted by MSHappyCampers

I can't imagine any MH of any size not having an exhaust brake!

Yes. Size. I'm only 26K max gross.
Next one will be near double that.

[ga traveler]

As service manager, I have driven many diesels to shows. I have driven small class b diesel vans and up to the fancy Blue Birds. I own a pace Arrow gas, but if I ever go diesel, it will have a exhaust brake.

[RickO]

When (as a newbie) I bought a new coach... one of the big reasons I went DP was the attraction of the engine brake. I was FAR more concerned with being able to stop 32000 lbs than I was in making it go.

It's a great relief having it. A couple of times I've had to make long, steep descents in foul weather so I couldn't use the engine brake. White knuckle time for sure.

Rick

[RustyJC]

Originally Posted by jrgreen

My 34ft, 22000 lb gas Bounder didn't have an exhaust brake and I did plenty of mountains with a toad and never felt that I needed one (would having one been nice -yes but not a deal breaker.

Gasoline engines don't use or need exhaust brakes. The throttle plate in the intake serves the same function. Diesel engines are unthrottled, hence the need for an exhaust brake to provide engine braking. If one has a choice on a diesel engine, an engine brake (aka "Jake brake") is preferable to an exhaust brake.

Rusty

[vtwinwilly]

Originally Posted by denochs

As far as claimed extra wear/stress on the turbo, hogwash! Those 80,000 pound trucks that have been using them and logging 500,000+ miles without a problem is proof of their usefulness and reliability.

My 03 has never had a brake problem. In fact, I still have the original brake shoes because of the jake brake. If you are familiar with Black Mountain on I 40 eastbound in NC, we manage to come down that hill holding back all 44,000 lbs without having to touch the service brakes.

Can't say enough about the comfort of having a backup to service brakes.

Dave

Someone may have noted this already, but most large trucks use a Jake Brake. A Jake Brake is not an exhaust brake, though it acheives the same or similar end.

A Jake Brake - that most large Grade 8 trucks use - is mounted to the head and actually controls the exhaust valves. It is usually installed at the engine assembly factory when the engine is originally assembled. A Jake Brake is a much more complicated and expensive device than a PAC Brake.

An exhaust brake - like a PAC Brake - is nothing more than a butterfly valve inserted into the exhaust downstream from the turbo. The theory being presented is, when that butterfly valve closes, all that exhaust heat is trapped behind it causing heat build up in the upstream section of the exhaust... including the mechanical components of the turbo.

What no one seems to be able to tell me, is what kind of premature failure - if any - are we talking about? Will a turbo without a PAC Brake last 500,000 miles? Will adding the PAC Brake reduce that to 300,000, 250,000, 200,000? Who knows. In most cases motorhomes never see this kind of mileage so on a motorhome maybe it's a non-issue.

[RustyJC]

Originally Posted by vtwinwilly

An exhaust brake - like a PAC Brake - is nothing more than a butterfly valve inserted into the exhaust downstream from the turbo. The theory being presented is, when that butterfly valve closes, all that exhaust heat is trapped behind it causing heat build up in the upstream section of the exhaust... including the mechanical components of the turbo.

What no one seems to be able to tell me, is what kind of premature failure - if any - are we talking about? Will a turbo without a PAC Brake last 500,000 miles? Will adding the PAC Brake reduce that to 300,000, 250,000, 200,000? Who knows. In most cases motorhomes never see this kind of mileage so on a motorhome maybe it's a non-issue.

Since an exhaust brake only engages when the accelerator pedal is fully released, no fueling is taking place; therefore, there's nothing going on to build heat up ahead of the brake. If one has an EGT gauge, they can verify this for themselves; just look at the temperature when the exhaust brake is in operation. Typically, a thermocouple in the exhaust manifold ahead of the turbo will read only about 450-500 degreesF when the exhaust brake is in operation, much lower than the 1150-1250 degreesF or even higher that might be seen at full throttle operation. Therefore, the turbo components aren't being exposed to temperatures even approaching what they're designed to handle.

The exhaust brake works by building up PRESSURE ahead of the brake's closed butterfly valve, not HEAT.

Rusty

[Luckiest Dreamer]

Originally Posted by mrblanche

As a trucker, I like having one. However, I went cross country many times with a 350 hp engine and 80,000 gross without an exhaust brake, and I never had any major problems. As others have said, they can make your life much easier. They also add more parts in the engine that can break and have to be replaced. Yes, it happens; I had a brand new engine in about 1995 that broke a part in the jake on the first use (less than 100 miles on the truck). In the next 5,000 miles, it did over $5,000 damage to the engine before it got repaired.

I worked for the largest parcel delivery company in the US driving 18 wheelers. They routinely purchased new vehicles that came with the Jake Brakes and one of the first things they did was send the truck to the shop to have it disabled. The cost for the repairs and the down time cost was enough for them to do this. I cannot ever think of a time that I felt I missed out on something because it was not available to me.
I now have one on my MH and am glad it is there.