Tim-n-Deb
Lancaster, CA
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Joined: 03/29/2006
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From previous post I submitted:
Quote:Just brought home our new motorhome and I have a couple questions (1st DP): 1. MH's with engine/exhaust brakes, do all of them turn on brake lights when they are activated? My wife followed me home and she was concerned that I was riding the brakes on a long downhill (which I wasn't, only using the retarder). 2. Was told by dealer that the engine will only output 40% power in 1st gear. Is this to help on the wear and tear of the tranny? My MH does move a little slow off the line, but picks up in 2nd. Do all MH's limit power in 1st gear? Thanks for your replies.
Since my motorhome limits power in 1st gear and into 2nd, will there be any difference in mpg from a "floor-it takeoff" to a moderate one? Is the transmission electronics controlling the engine electronics?
Thanks, Tim
2008 Fleetwood Expedition
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KOG
Winterville GA
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The limit in lower gears is to avoid exceeding the torque capacity of the transmission in those gears. The transmission computer tells the engine computer which gear it's in and the engine computer limits torque as programmed. Basically no effect on fuel consumption. Just put the pedal down and wait for it to get up to speed.
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YC 1
Yuba City Calif.
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As for the brake lights coming on mine do not. However I have read on this forum of others that do so it sounds like Mfgr preference. Yes your computer will protect your transmission. I can't put mine in gear if above an idle.
H/R Endeavor 2008
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Mandalay Parr
Phoenix, AZ
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I was told that by law, the brake lights are on when the exhaust/engine brake is activated to let others know that you are slowing down.
Jerry Parr
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2005 Mandalay 40B
Cat C7 350, 4 Slides
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BigRigRVing
formerly CA
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My brake lights come on as well on coach and jeep we tow behind.
Gary & Cheryl and our chocolate lab named Caddy
2005 Newmar Mountain Aire 4304 w/ Blue-Ox Sports Lift
2006 Jeep Rubicon
HD 2006 Softtail Deluxe
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mscamping
any place, USA
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The engine has it's own computer, and so does the transmission.. They are connected and communicate as to what each need to do.. Yes it does affect mileage and wear and tear on all drive line parts when you put the pedal to the floor and hold it.. You're putting the maximum allowed when you could put less on by giving it less pedal therefore not using as much fuel.. Why would this be any different than anything else?? No our brake lights do not come on with the exhaust brake.. Do you have a retarder or exhaust brake?? Yes I would say that nearly all are limited until they get in the higher gears and/or the converter locks up.. I wouldn't believe a thing that a dealer tells me.. I would ask the people that make the equipment, Allison or Cummins.. Hope this helps..
Mike..
2003 Holiday Rambler Neptune 36 PBD 38' - ISB 300 Cummins w/Allison MH2000 5 speed
2009 HHR w/Blue Ox Aventa II & SMI Stay-n-Play Duo
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Mike & Sharon
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Deen
Vancouver, WA
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Tim-n-Deb wrote:From previous post I submitted:
Quote:Just brought home our new motorhome and I have a couple questions (1st DP): 1. MH's with engine/exhaust brakes, do all of them turn on brake lights when they are activated? My wife followed me home and she was concerned that I was riding the brakes on a long downhill (which I wasn't, only using the retarder). 2. Was told by dealer that the engine will only output 40% power in 1st gear. Is this to help on the wear and tear of the tranny? My MH does move a little slow off the line, but picks up in 2nd. Do all MH's limit power in 1st gear? Thanks for your replies.
Since my motorhome limits power in 1st gear and into 2nd, will there be any difference in mpg from a "floor-it takeoff" to a moderate one? Is the transmission electronics controlling the engine electronics?
Thanks, Tim You don't have a "retarder" you have an exhaust brake or a engine (Jake) brake. The only one that uses a retarder is Foretravel.
Only the center light illuminates on our DSDP when the exhaust brake is on.
I know the Cummins are limited in at least 1st gear and maybe 2nd.
Deen - Vancouver, WA
'02 Dutch Star 4090 (41+', triple slide)
435/1200 ISC Cummins/Banks PowerPak
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ShapeShifter
Buffalo, NY
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YC 1 wrote:As for the brake lights coming on mine do not. However I have read on this forum of others that do so it sounds like Mfgr preference.
Are you sure you don't have something wrong with yours? Mine does turn on the brake lights when the exhaust brake is active, as do most that I have seen or heard about. Seems to me that it would be unusual for the manufacturer to change their preference from one model year to the next. Double check your owner manual, I seem to recall that mine specifically states the brake lights do come on with the exhaust brake. Maybe you have a blown fuse or bad relay?
In my case, I can point the rear vision camera all the way down, and just catch the center mounted brake light at the bottom of the monitor screen and see what it's doing. I was able to determine that the light comes on the instant I fully lift from the accelerator, even though the brake doesn't take effect for a second or two. I assumed that the light had the same delay, but that's not the case, at least for me.
2007 Holiday Rambler Endeavor 40PDQ
400 ISL Cummins/Allison
2002 Chevy Avalanche toad
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Sully2
Cincinnati
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ShapeShifter wrote:YC 1 wrote:As for the brake lights coming on mine do not. However I have read on this forum of others that do so it sounds like Mfgr preference.
Are you sure you don't have something wrong with yours? Mine does turn on the brake lights when the exhaust brake is active, as do most that I have seen or heard about. Seems to me that it would be unusual for the manufacturer to change their preference from one model year to the next. Double check your owner manual, I seem to recall that mine specifically states the brake lights do come on with the exhaust brake. Maybe you have a blown fuse or bad relay?
The exhaust brake / brake light thingy depends on the YEAR OF MANUFACTURE! My coach is a 2000 model and its lights DONT come on but about..??..2003-2004...they typically DO come on with the exhaust brake
2000 Country Coach Allure; Cummins ISC 330 HP; 71/2 - 8 MPG regardless
2002 Jeep Liberty
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YC 1
Yuba City Calif.
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ShapeShifter wrote:YC 1 wrote:As for the brake lights coming on mine do not. However I have read on this forum of others that do so it sounds like Mfgr preference.
Are you sure you don't have something wrong with yours? Mine does turn on the brake lights when the exhaust brake is active, as do most that I have seen or heard about. Seems to me that it would be unusual for the manufacturer to change their preference from one model year to the next. Double check your owner manual, I seem to recall that mine specifically states the brake lights do come on with the exhaust brake. Maybe you have a blown fuse or bad relay?
In my case, I can point the rear vision camera all the way down, and just catch the center mounted brake light at the bottom of the monitor screen and see what it's doing. I was able to determine that the light comes on the instant I fully lift from the accelerator, even though the brake doesn't take effect for a second or two. I assumed that the light had the same delay, but that's not the case, at least for me.
I will check the manual but don't recall ever seeing that. I have had my wife following me with a radio to specifically tell me if they come on because I was curious.
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