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Discussion Starter #1
What is the normal operating procedure for the foot-activated exhaust brake ?

Let's say you are going down a hill and you need to slow down/brake the truck, do you stab that knob and hold it or you give it a couple spaced shots ?
 

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'91 427.110 '02 405.230
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You stab it and hold it.
Once you try it, you will know how it works.
The higher the rpms the more of the braking effect you get.
 

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mogless, except for my friends MB4-94. And a bunch of other diesel junk.
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Is it loud like a "jacob" brake system ?

I sure hope so !
Why is that so?
In most of the cities you're not allowed to use them, so it is good they're quiet.
This way you can still use them and save your brakes.Plus it works pretty good on slippery surface too.I wish my Mog had ABS.
 

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Vehicle: 1397 Portative Organ Normally Aspirated....U411, U2450,463 300GD
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Don't mess with 'em too much...unless you have a nice fence or garage for the mog; tires are expensive. I think you will find the exhaust brake quite quiet, nothing like a jake. I also found out if you are in "Georgia Overdrive" ie. rolling down a hill in neutral and you hit the exhaust brake the engine will shut off-duh. You could always get a locomotive horn.
 

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'88 U-1300L, '70 406, '78 406, '78 416 project, '82 406, '57 404, '65 404, '70 404, '68 Haflinger.
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...chop.... I also found out if you are in "Georgia Overdrive" ie. rolling down a hill in neutral and you hit the exhaust brake the engine will shut off-duh. You could always get a locomotive horn.
Exhaust brakes are wonderful on the big mogs. Should make the brakes last 3 or 4 times longer.

If you are engine braking going down hill, shift, and the Claas overdrive misses a gear and drops into neutral, the next press of the exhaust brake will also kill the engine. Not fun at 60 mph, LOL. Little lessons best thought about ahead of time.

I added a Packbrake to my Dodge/Cummins mog hauler....best upgrade I ever did. I can cross the Rockies and never have to use the brakes, as long as I keep it in a reasonably low gear.

(added) Always listen to the brake open again. Sometimes my exhaust brake sticks closed until engine speed drops to near idle. Gotta be sure it opens up before applying throttle or exhaust temps really go up!

Bob
 

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Vehicle: 1397 Portative Organ Normally Aspirated....U411, U2450,463 300GD
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Hah...If the pic is not a photoshop someone is having fun with horns!
It is a technique (exhaust braking) I will have to practice. I am used to just flipping the 1, 2, or 3 on a jake (great for the fantastic stop and go traffic we get here) so now it is something to keep my clutch foot busy.
 

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BenzWorld UNIMOG statesman
Unimog 404.1 Diesel (sold :( )1995 LMTV 1078
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Hah...If the pic is not a photoshop someone is having fun with horns!...
full size pick (just click on it)looks to be real. All the weld and bolt on racks that hold it up are visible.

He must have one hell of a compressor stuffed in their somewhere too.
 

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U1600Ag
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Discussion Starter #12
exhaust brake got stuck

My exhaust brake got stuck on the ''on'' position while riding on the highway, again. The first time it happened, it was -20c, so I thought that it was just frozen. This time, I cannot explain why it got stuck.

Is there a way to lubricate/clean that foot switch so it doesn`t happen again ?

How do you get it unstuck safely while still rolling ?

I read that you should`t floor the gas pedal, because the exhaust temp could run pretty high.

I didn`t thought about looking at my EGT gauge while it was happening, because I was freaking out a bit, I was in a tunnel, at 90kph, in heavy traffic. I kept stabbing that switch and it released after a while.
 

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'88 U-1300L, '70 406, '78 406, '78 416 project, '82 406, '57 404, '65 404, '70 404, '68 Haflinger.
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It's probably not the switch/valve itself, it's probably the butterfly valve in the pipe getting stuck closed. My 1300 does that occasionally (hot, cold, doesn't seem to matter). I have lubed the shafts with some graphite lube and it seemed to get better. When mine sticks the engine speed has to drop to 1000 rpm or so (reducing exhaust flow) and the brake opens. Try hitting the clutch next time it happens.

This issue came up before and someone pointed out there is a precise method of adjusting the idle speed of the engine, and the setting of the hand throttle, that effects the engine brake dropout. Can't remember where that info was discussed. The adjustment procedure is in the manual.

Bob

My exhaust brake got stuck on the ''on'' position while riding on the highway, again. The first time it happened, it was -20c, so I thought that it was just frozen. This time, I cannot explain why it got stuck.

Is there a way to lubricate/clean that foot switch so it doesn`t happen again ?

How do you get it unstuck safely while still rolling ?

I read that you should`t floor the gas pedal, because the exhaust temp could run pretty high.

I didn`t thought about looking at my EGT gauge while it was happening, because I was freaking out a bit, I was in a tunnel, at 90kph, in heavy traffic. I kept stabbing that switch and it released after a while.
 

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Discussion Starter #14
It's probably not the switch/valve itself, it's probably the butterfly valve in the pipe getting stuck closed. My 1300 does that occasionally (hot, cold, doesn't seem to matter). I have lubed the shafts with some graphite lube and it seemed to get better. When mine sticks the engine speed has to drop to 1000 rpm or so (reducing exhaust flow) and the brake opens. Try hitting the clutch next time it happens.

This issue came up before and someone pointed out there is a precise method of adjusting the idle speed of the engine, and the setting of the hand throttle, that effects the engine brake dropout. Can't remember where that info was discussed. The adjustment procedure is in the manual.

Bob
I think it was B101UK that was speaking about the idle adjustment in relation with the spud brake.

Is there any pics around of that lube point ?
 

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I don't have a photo but it's easy to find. Just look for the air cylinder that actuates the air brake butterfly valve, and lube the valve shaft where it enters the exhaust housing (part of the cast manifold on my truck). There's a pivot point on the backside too, danged hard to see, and I got to it only with a screwdriver shaft, letting the lube run down the shaft.

BTW, when you lift your left foot off the brake actuator, you should hear air escape. That should retract the spring loaded air cylinder. You can also hear if the brake opens or not. After thinking about this, the sticking point could be the air cylinder piston. I think I'll try to lube mine by injecting a little of the graphite there too.

There was an earlier question about how to use the brake, to hold it on or to apply it in spurts. Either way is the answer...whatever is needed. I have held my brake on for miles, like coming out of the Rockies. Obviously the injector pump should not be injecting at this time (there's a control cylinder to make it throttle back). I usually check the pyrometer occasionally to be sure temps are low. Exhaust temp will really drop under those conditions.

Bob

..chop...
Is there any pics around of that lube point ?
 

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Discussion Starter #16
I don't have a photo but it's easy to find. Just look for the air cylinder that actuates the air brake butterfly valve, and lube the valve shaft where it enters the exhaust housing (part of the cast manifold on my truck). There's a pivot point on the backside too, danged hard to see, and I got to it only with a screwdriver shaft, letting the lube run down the shaft.

BTW, when you lift your left foot off the brake actuator, you should hear air escape. That should retract the spring loaded air cylinder. You can also hear if the brake opens or not. After thinking about this, the sticking point could be the air cylinder piston. I think I'll try to lube mine by injecting a little of the graphite there too.

There was an earlier question about how to use the brake, to hold it on or to apply it in spurts. Either way is the answer...whatever is needed. I have held my brake on for miles, like coming out of the Rockies. Obviously the injector pump should not be injecting at this time (there's a control cylinder to make it throttle back). I usually check the pyrometer occasionally to be sure temps are low. Exhaust temp will really drop under those conditions.

Bob
Good info ! Thanks !


Should heavy grease be used ? Or spray-on type would be ok (Fluid Film ?)
 

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There is also a pivot point for the linkage near the throttle, mine was seised there when I got my truck.
 

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Considering you are lubing something that will approach 1200 degrees F, I recommend the graphite lube made for locks, in the light fluid carrier. The fluid evaporates quickly leaving the graphite which handles the temp just fine.

Should heavy grease be used ? Or spray-on type would be ok (Fluid Film ?)
 
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