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Author Topic: steep hills and no jake break??  (Read 8071 times)
BRUISER
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« on: October 26, 2011, 11:26:23 AM »

I have a '83 MCI-9 5 speed manual with no jake break and I have a trip coming up where I will be going up and then back down a 7% grade or more..

what I am curious to know is if I get bus into 3rd gear on way down will the tranny hold it at a speed or will it try to run away and over rev the engine?

I have had smaller diesels in the past  that even if i had it in a gear, engine would continue to rev to the point I would have to use the breaks to slow it down..

so if tranny will hold the speed do I need to watch other things? will engine heat up doing this etc?

thanks in advance
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iMPAKS.com
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« Reply #1 on: October 26, 2011, 11:51:24 AM »

Slow your arse down.. with your old bus, go up in one gear, go down in one gear lower.

We would rather see you in a lively state than mourn over your cadaver in a casket.
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I'm just an old chunk of coal... but I'm gonna be a diamond someday.
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« Reply #2 on: October 26, 2011, 11:55:36 AM »

well some of you may actually know the hill I am talking about.. it is Black Mountain in NC.

Anyone have experience as to what gear you use when pulling up the mountain? I am curious..
I have no issues going slow at all, that is why they have the slow lane on that mountain Smiley

I figure I will find out pretty quick when I get to it and fell the bus slowing down.. but I am a planner so the more I know before hand the better I feel.
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iMPAKS.com
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« Reply #3 on: October 26, 2011, 12:36:36 PM »

   well some of you may actually know the hill I am talking about.. it is Black Mountain in NC.  (snip)
 

    Yeah, they call that the Old Fort grade on I-40.  I can't help with bus info but I was through there a couple of weeks ago in my car.  To make things worse, they are (were - maybe it's over) doing road construction on the center division and barricade so it's down to two lanes going up and coming down.  My memory is that the real work is about right in the middle of the grade but of course, the closed lanes extend down the hill on the west-bound side and up the hill on the east-bound.   Good luck with this one.
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Bruce H; Wallace (near Wilmington) NC
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« Reply #4 on: October 26, 2011, 01:08:08 PM »

  Do you want to BREAK it  or do you want to BRAKE it.??>>>D
« Last Edit: October 26, 2011, 01:11:14 PM by Utahclaimjumper » Logged

Utahclaimjumper 
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« Reply #5 on: October 26, 2011, 01:18:27 PM »

Yeah, that's an intense little stretch... I know it well.  The runaway truck ramps are a grim reminder of what could happen!

Not to hijack the thread, but I would also wonder what the best strategy would be to climb and descend a grade like that with an automatic (Allison 740) with no jakes...

Marc
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« Reply #6 on: October 26, 2011, 01:21:42 PM »

The old rule of thumb was to go down the hill in the same gear you came up it.  Don't be affraid of using your brakes-just don't stab them hard-long gentle applications work best to not over heat the brakes.  Good Luck, TomC
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« Reply #7 on: October 26, 2011, 01:39:15 PM »

You can always gear up if you start too low but you may not be able to go the other way.  The steepest grades I have run without jakes are on the 97C connector between Kelowna and Merritt.  Officially they are mostly 6% grades but some of them go on for 8 or more miles and I don't know how they measure them but they are the steepest 6% grades I have run into.  Its truly surprising how low you need to go before the engine provides any measurable holding.  Start low.
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R.J.(Bob) Evans
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lostagain
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« Reply #8 on: October 26, 2011, 05:09:45 PM »

I used to drive for Brewster's in the Canadian Rockies in the '70s. We didn't have Jakes then. Go down the hill in the same gear you go up it. Sometimes even lower. Slow with the 4 way flashers on. And like TomC says, light, steady pressure on the brakes. Jakes are nice to have, but not a necessity.

JC
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JC
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« Reply #9 on: October 26, 2011, 05:12:05 PM »

Great thread! we are planning to go to that exact area next year, maybe as early as March. I never thought about planning the roads and knowing the grades, where do you get that info?
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Mike & Rosemarie
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« Reply #10 on: October 26, 2011, 05:40:58 PM »

I go down steep mountains in my 33k# RTS, and do fine without Jakes.  Experts say that stabbing your brakes to slow you down is better than "riding" your brakes-- I apply mine for a few seconds with force then let up wait a few seconds and do it again and it has worked for me.
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Geoff
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« Reply #11 on: October 26, 2011, 05:56:33 PM »

Light, steady brake application puts less heat into the brake drums. If you stab the brakes hard for short times, it puts a lot more heat into the drums. And it takes hours for them to cool off.

We used to shuttle skiers up and down to Sunshine ski area near Banff before the first gondola was built in '79. One winter we had some tests done on brake drum temperatures. The least heat was achieved by light, steady application. And the recovery times to cool off were long. Much longer than the 15 mn dead head back up the hill. I remember them saying how there was still heat in the drums the next morning after sitting all night. We were taught to go down in the same gear as going up, sometimes one gear lower yet, whatever it took, no matter how slow it seemed.

JC
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JC
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Melbo
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« Reply #12 on: October 26, 2011, 06:02:49 PM »

Someone on this board posted that you can go down lots of hills too slow but only one too fast.

That has been my watch words as I drive the mountains here in the west.

HTH

Melbo
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« Reply #13 on: October 26, 2011, 06:19:22 PM »


I bring HUGGY down in 2 gear. "A v730 and 6v92 in a 04"

Just start slow and and i very seldom use the brake.  I have jakes but really don't use them unless I am following a slow Truck.

uncle ned
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« Reply #14 on: October 26, 2011, 06:42:04 PM »

  This is an interesting topic, I was just wondering some of this same very stuff.

  I was always taught to brake down well below speed, then let up to cool and try to hold your speed back with gearing. Now your all saying long and steady. Maybe over the winter I can find some Jakes somewhere, I hate burning up brakes.

  Not that we have any hills over here in the Ozarks y'all would get excited over, but still.

  I dont recall the stretch of 40 your talking about, but getting over the top there are some fairly long grades. My Uncles over near Franklin, and I once made a wrong turn and was headed for Maggie Valley. That is one steep road.

  Curious, are there different grades of brake lining material we can run, metalic, semi metalic, different compounds etc., or is Bus brakes just Bus brakes.
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