a388666 Report post Posted June 28, 2020 (edited) 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 June 28, 2020 by A388666 Added exhaust brake Share this post Link to post Share on other sites
wildebill308 Report post Posted June 28, 2020 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 Share this post Link to post Share on other sites
manholt Report post Posted June 29, 2020 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? Share this post Link to post Share on other sites
rsbilledwards Report post Posted June 29, 2020 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... Share this post Link to post Share on other sites
wildebill308 Report post Posted June 29, 2020 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 Share this post Link to post Share on other sites
manholt Report post Posted June 29, 2020 A388666. Just out of curiosity, why not change the A# for a F#, now that you have a coach? Share this post Link to post Share on other sites
rsbilledwards Report post Posted June 29, 2020 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. Share this post Link to post Share on other sites
manholt Report post Posted June 29, 2020 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. Share this post Link to post Share on other sites
rayin Report post Posted June 29, 2020 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. Share this post Link to post Share on other sites
dickandlois Report post Posted June 30, 2020 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. Share this post Link to post Share on other sites
manholt Report post Posted June 30, 2020 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! Share this post Link to post Share on other sites
rayin Report post Posted July 1, 2020 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. Share this post Link to post Share on other sites
campcop Report post Posted July 5, 2020 (edited) 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 July 5, 2020 by campcop Share this post Link to post Share on other sites
manholt Report post Posted July 5, 2020 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! Share this post Link to post Share on other sites
wayne77590 Report post Posted July 6, 2020 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? Share this post Link to post Share on other sites
rayin Report post Posted July 6, 2020 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. Share this post Link to post Share on other sites
jleamont Report post Posted July 6, 2020 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. Share this post Link to post Share on other sites
manholt Report post Posted July 6, 2020 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. Share this post Link to post Share on other sites
hermanmullins Report post Posted July 6, 2020 Good thought to use your Blinkers, I do the same when merging onto traffic when I am trying to get up to speed with the traffic. Herman Share this post Link to post Share on other sites
wayne77590 Report post Posted July 7, 2020 On 7/5/2020 at 10:09 PM, RayIN said: 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. Thanks Ray. Share this post Link to post Share on other sites
manholt Report post Posted July 7, 2020 We just don't sound like a un muffled 18 wheeler! Share this post Link to post Share on other sites
wayne77590 Report post Posted July 7, 2020 (edited) 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 July 7, 2020 by wayne77590 Share this post Link to post Share on other sites
rayin Report post Posted July 8, 2020 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. Share this post Link to post Share on other sites
manholt Report post Posted July 8, 2020 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! Share this post Link to post Share on other sites
wildebill308 Report post Posted July 8, 2020 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. Bill Share this post Link to post Share on other sites
