Jake Brakes......

My trainer had me go down a mountain without the jake. All i had to do was choose a gear that was a lot lower than i would have with using the jake. The engine wouldnt go above 1600 rpm, i stayed at a steady speed. If i picked up speed then i was to brake until i came down to my "target speed".

Is this how you train? Im just curious.

 

I am glad that there are still people out there that haven't lost their minds and teaching the correct way of doing things. However, sadly there are drivers out there that aren't being taught correctly. I think we all know the TV show Ice Road Truckers is mostly editor driven fake tension but I did watch the 1st season they were in Alaska and one of the "rookie" drivers they rode with actually said when coming off one of those hills on the Dalton in a snow storm "his jake was causing his wheels to lock up so he had to turn it off", his words. They showed him fiddling with the 3 position selector switch and it was all the way up. Using all 6 cylinders on an unpaved road in the middle of a winter storm? I wouldn't feel great about using 2 or 4.

As far as coming down a hill w/o a jake, I have heard of two methods, the one I never tried (because I am not suicidal) came from a safety trainer from the company we leased our trucks from and involved keeping "constant light pressure" to not allow oxygen to get between the brake pad and drum. Wanting to live, I followed option 2, using the same gear to go down that you would use coming up, allowing for the engine to do most of the braking. I would cheat by using the air application guage, if I needed to use more than 25psi to maintain your speed with "periodic" braking, it was time to get a lower gear.

In regards to not having jakes and coming off a mountain slow and steady, you are preaching to the choir. I didn't get a truck with a jake until I had been driving for 10 years, pulling oversized utility poles from LR, AR to Joplin, MO over the old Hwy 71. We were running Cummins 350 big cam's with an operating range of 1800-2100rpm's and I think running those higher rpm's gave the "C brake" much better stopping power than on the low rpm engines of today. Back then when grossing closest as possible to 80k there was more than a couple of hills that you actually got down to the low side of the transmission, I would enjoy running that old road with a 500 plus HP engines of today.

 

Sign me up for that ride....

"Jake brake" has become a generic term... and it's the same as "engine brake".

Whether it's a genuine Jake Brake from Jacobs or a "C-Brake" from Cummins or a "Pac-Brake" they all operate on the same principal... they shut off the fuel and open the exhaust valves just before ignition to effectively make the engine an air compressor.... and help slow the vehicle.

"Exhaust" brakes, like those used on Mercedes and other engines, are a different design. Just like the old Williams "Blue OX" exhaust brakes they use a gate valve or guillotine valve to shut off the exhaust to control engine rpm's and slow the truck.

So, if you have a Jake, C-Brake or Pac-Brake you have an engine brake. If you have a Mercedes, Volvo or other Euro engine you have a "exhaust" brake...

BTW...my '96 FLD with a Detroit had an aftermarket "exhaust" brake....

 

That's a problem between management and the shop. If it's just your truck you should write it up on your inspection report. If it's a problem with other trucks then it should be talked about at your next safety meeting.

 

Krooser, you know when you try to edit something and b/c you know what you are trying to say, it makes sense in your head but is confusing to others. I used the term" C brake" because that was one of the 1st year models, 1987, that engine manufacturers began using their own designs as engine brakes. I heard but never went out of my way to confirm that this was when Jacob's patent was expiring. Running 2100rpm's even though entirely stock, it sounded like a 20mm Vulcan cannon and felt much more effective than an engine with 150 more Horsepower running in the 1500-1800rpm range.

I ran across the following legal oppinion while researching the subject; http://www.cga.ct.gov/2004/rpt/2004-R-0741.htm

The law in Springdale, AR actually makes me cringe to think about it, "Springdale, Arkansas, prohibits as a nuisance engine brake noise emission, except when such devices are used as a safety device (Springdale County Code § 42-52(13)." Because of irresponsible use, it sounds like the decision of where it is proper to use has been taken out of the hands of the driver and turned over the police and judical system.

One type of retarder I have read about but have never seen is the electro magnetic driveline retarder.* Trains have been using them for a while. I have only read about them being used in road applications like fire trucks but with manufacturers marketing hybrid tractors (Wal-Mart has tested Pete 386 hybrids**) this technology is going to become more and more popular. The firetrucks had magnets mounted on the driveshaft, that are surrounded by magnets in a stator. when current is applied the magnets become polar opposites creating a force that causes the driveshaft rpm to decrease. The retarder easily mounts to axles as well and becuase it charges itself going down the road, their use is not limited to powered axles. Which means it's braking power is not limited to the drive axle, they can go on ther steer and trailer axles, all providing braking power (charging themselves in normal driving) with no wear and tear on the engine, brakes, or tires.

* http://www.industrialbrake.com.au/driveline_retarders.htm#general
** [ame]http://www.youtube.com/watch?v=E_FrmlVG_Mw[/ame]

 

The magnetic retarders have ben used in Europe... not sure if they still are used. They are very heavy...IIRC about 1500#'s so I would seriously doubt they will ever be popular here but I could see their valid use in some heavy haul applications....

Don't forget Cat's "Brakesaver" retarder...

And remember that "retarders" are different than re-tards!!!