What are these "retarders" and how do

Engine retarders, engine brakes, jake brakes, and compression brakes are all terms used for the same device. Basically, they slow the engine down without applying braking directly on the wheels. By slowing down the engine, you will be indirectly slowing down the rest of the drivetrain and your vehicle will slow down as a result of it.

On slippery conditions they can slow things down to the point where your wheels lose traction and can lock up!!! (just as if you had slammed on your brakes).

Some jake brakes have multiple settings. On dry pavement I'm usually on the highest setting. On slippery pavement (wet/snow/ice), I'm either on the lowest setting or I have them turned off completely.

Your drive axles are the back axles on your tractor. A rear wheel drive car/truck has the back axle being the drive axle. A front wheel drive car has the front axle as being the drive axle. It's the axle that drives the vehicle.

 

Hell, I always thought the retarders were the guys/gals who worked dispatch, aka driver managers!


Oh wait, those are not retarders, they are just re tards...

 

Yeah, but she's talkin about engine retarders. I think that actually might be confused with a mechanic in a Werner maintentance garage.

 

Yeah that is a jake brake. The guy who invented them was named jacobson I believe or close to that anyway. He has a patent on them and they are called jakes for short, but it is a engine retarder that helps the truck descend on mountains and saves the braking system. Even the Army had them on the 9-15's semis in the 1980's.

 

I don't use the engine brake except doing down grades. I really don't see a need for it and I did alot of city driving. I'd much rather time the lights and just cruise through. Besides, most times I would end up at the same place and the same time as the truck racer. Some towns and cities will allow engine brakes and some don't. Some won't allow them when you really need them but that's the law.

When you get out on the road you'll start learning downhill operations. This is where you'll want the engine brake so you'll have plenty of friction brakes to stop in an emergency. The ideal situation is to go down the hill and tapping the foot brakes only a couple of times. It's easy to do but you have to pay attention on what's going on around you. You'll also learn that driving a truck using all your senses so you'll use sight, smell, sound, and feel especially going down the mountains.

 

Jake Brake Theory of Operation:
http://www.jakebrake.com/products/how-the-jake-brake-works.php

 

they arent legal everywhere cuz there so #### loud

 

I try to use the Jacobson ("jake") brake (engine retarder) all the way down and add a little trailer brakes if necessary. Then the tractor brakes are always cool. If I have to apply the tractor brakes more than a few times, I slow down with my still-cool brakes, then drop a gear so the engine can pull the speed down better, just as it is more efficient going uphill in a lower gear.
BTW - The way I understand it, the engine retarder changes how the valves open and close. So, instead of the engine using compression/explosion to produce power, it uses compression/release to the atmosphere (with attendant noise) to "use up" the energy created by the truck going downhill.
Hard to believe that it is still allowed (by any company or by the government, which knows best ), to go down a big hill without an engine retarder. Coming east out of San Diego, there is a hill on I-8 from about 4200 feet. Not that bad, 6 or 8 miles at 6% I guess, but the speed limit is 35 for trucks. If you are grossed out w/ no engine retarder, you have to go 12 mph in 4th gear at 2000 rpm w/ some trailer brakes applied, if you want to save the tractor brakes. Did this with 9000 gallons of gasoline - dispatch, all wrapped around "don't go over 55 ever, don't stop to eat or for any other reason while loaded, lock your doors when loading/unloading," etc., etc., never worried about sending a truck "over the hill" w/o an engine retarder.