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Exhaust Brake use Tiffin diesel pusher

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New to driving and will be going down steep grade in the mountains can someone advise the process to engage exhaust brake 2011 Tiffin Allegro

Edited by A388666
Added exhaust brake

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Welcome to the forum. Which Tiffin model as some have different engins.

I would drive with it on so you can get a feel for how much it breaks and how it feels before you are on THAT hill. Basically it starts to slow and downshift any time you reduce the throttle. It's goal is to slow you to 2ed gear. Plan on slowing at the top of any steep hill. I have seen places where trucks were required to start down the hill at 30 mph or less. A good saying is "never start down a hill faster than you came up it". 

Let me know if you have any questions.

Bill

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Unless your in some backwater countries, you'll always have a signage that gives the % of incline for the downward grade ahead.  Some coaches have a high engine brake and some have high & low. Last year in a coach with a Cummins 425 HP, I used Low for the first time ever...27% grade down, low is running on 2 cylinders in 2nd gear, then 1st gear!  High is 4 cylinders and you can start in 4th gear...again, as Bill asked, what engine HP or Model Tiffin do you have?

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There is no substitute for miles driven. What WildBilloffers is very true and correct but in addition it is likely not to hold a given speed particularly a steep downgrade. Momentum will build necessitating use of your brakes. There is a particular manner in which to use them and it is not constant use. It is a generally accepted practice to allow 5 or 10 miles and hour build in speed and then hard brake the speed back to what you are comfortable with or that 30 MPH suggested for truckers hauling a load. This affords time for the brake pads and rotor to cool for the next application. Practice makes it easy.  

Carl has made another point, the one about high and low. This unfortunately does not apply to you as he references features included with a JAKE brake which is only found in larger displacement engines CAT or Cummins. Smaller unit like yours utilize the PAC brake or exhaust brake.       

Welcome to the forum there are no dumb questions except the one you failed to ask...         

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1 hour ago, RSBILLEDWARDS said:

Momentum will build necessitating use of your brakes. There is a particular manner in which to use them and it is not constant use. It is a generally accepted practice to allow 5 or 10 miles and hour build in speed and then hard brake the speed back to what you are comfortable with or that 30 MPH suggested for truckers hauling a load. This affords time for the brake pads and rotor to cool for the next application. Practice makes it easy.  

This is true however I found if I slowed enough to get down to 4th it would hold speed pretty good on most hills. if it didn't and kept picking up speed I could slow to where it dropped into 3ed gear and then I bet I could go down a 35 degree slope without picking up speed.

A388666, Still my advice is to drive with it on and get a feel for how it reacts to different  situations. 

Bill

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A388666.

Just out of curiosity, why not change the A# for a F#, now that you have a coach? :rolleyes:

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Mr. Bill I do not believe that leaving it on all the time is a good practice for the long haul. Dave Atherton has commented on issues caused by this practice. Ok for the period of time learning how it reacts. I can tell you in the mountains of Colorado there are passes where it will pick up speed, hence my input.

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Rolling wheels, weight and inertia, makes for some interesting moments on Steep down grades!  I have pulled over in the truck brake check area on more than a couple of times!  Safety First.

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Learning by personal experience is vital before it really counts. There is a quirk about exhaust brakes you should know. The engine and transmission computer controls (ECM and TCM) will automatically protect the engine from over-revving damage, you have no input.

When the ECM and TCM sense the engine RPM is too high(this is in your owners manual) the ECM will command the TCM  to upshift the transmission the the next higher gear. At that point your only recourse is to slow your speed with your service brakes enough for the transmission to  downshift when engine RPM's are low enough to prevent engine damage.

The bottom line is; always begin your descent of steep grades slowly with exhaust brake on, using service brakes as necessary to maintain a safe speed and control engine RPM.

I agree with the suggestion to drive with the exhaust brake on  to get the feel of what it does and how it affects forward motion. Once that is learned you can leave it off until needed.

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A388666, Welcome to the Fmca Forum !

The one item I did not see posted in response  to your request is The exhaust brake does not work when the Cruse Control is engaged. As soon as you touch the brakes it is disengaged and you will notice the real time affect of the Exhaust brake. If it is turned on !

Rich.

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Rich, that's one good reason to study, all your toggle switches location and function, before you engage gear and go!  Hunt and peck at 60+ mph is not a good thing!!! 

If you don't have a Owners Manual of Engine, Chassis and Coach, in most cases it's available on line!  

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On 6/29/2020 at 9:29 PM, DickandLois said:

A388666, Welcome to the Fmca Forum !

The one item I did not see posted in response  to your request is The exhaust brake does not work when the Cruse Control is engaged. As soon as you touch the brakes it is disengaged and you will notice the real time affect of the Exhaust brake. If it is turned on !

Rich.

Well, mine does. When I'm in small rolling hills with CC switch on, every small descent triggers the exhaust brake; very annoying, which is why I leave it turned off until actually needed. A388666 needs to drive with the E-brake turned on until he learns by experience how his particular MH reacts.

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On 6/28/2020 at 3:53 PM, A388666 said:

New to driving and will be going down steep grade in the mountains can someone advise the process to engage exhaust brake 2011 Tiffin Allegro

I don’t know what braking system you have for a towed vehicle but be aware on Tiffins, exhaust or engine brake use will also light up the brake lights when activated.

A good thing as mentioned is to not to start any faster going down that going up. When braking, use a firm brake for a short time to slow and the release the brake, do not ride the brake or use excessively.

Edited by campcop

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If the toad brake system is AF! or M&G, it will not activate toad brake lights when using engine or exhaust braking in coach!   

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My system is AF1 but the brake lights are hooked to the umbilical cord and they dome on when the exhaust brake is on.

I have a two stage, is that exhaust of jake?

 

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1 hour ago, wayne77590 said:

My system is AF1 but the brake lights are hooked to the umbilical cord and they dome on when the exhaust brake is on.

I have a two stage, is that exhaust of jake?

 

The sales brochure states "Allison® 3000 MH 6-speed electronic transmission w/2-stage engine compression brake". That is commonly referred-to as a Jake brake.

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Most RV's illuminate the brake lights with the exhaust or engine brake on. Its a changeable setting in the Cummins software if its equipped with a Cummins engine. Most trucks, medium and heavy do not illuminate the brake lights with the exhaust or engine brake on. 

I have read several complaints over the years from consumers utilizing a toad braking system that engages with inertia or via brake lamp illumination. AF1 and M&G both utilize air pressure to engage the toad brakes, not the stop lamp circuit.

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That's why, on long steep downhill runs, with engine brake on, I use my emergency blinkers, at speeds under the posted speed limit, mostly at 50 or less!  For the benefit of cars.

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Anytime I roll into a place that has a sign that says, "No Exhaust Brakes," or "No Jake Brakes," I have to admit that I totally disregard them. The exhaust or Jake brakes are safety issues. They stop my GVWR 45,600 pound MH towing a car a lot faster when I do have to apply the brakes than if they were off.

The ordnance is to placate the people who have complained about the noise. Yes, the 18 wheelers are very noisy compared to my MH. 

On the other hand, if I turn it off and the just downshift - I get basically the same stopping power and the SAME noise.

Edited by wayne77590

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Ya, there's huge difference between your MH and an 80,000# semi with straight-thru exhaust exiting12' in the air. I would do the same as you if I had an compression brake.

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Forget the 80,000#!  My coach is rated 68K#, Prevost is 75K#. Newell is 72K#...not enough difference to worry about.  6" straight pipe's with the Capt. choice wide open does make a little noise!  In TX is mostly gravel trucks!  Last time I was in Montana, it was Cattle (6 trailer's) haulers! :lol:

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I am looking forward to trying the engine break on this coach. I didn't turn it on this last trip to OK. I realey didn't need it in the mountains of north Texas. :D

Bill

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