ENGINE BRAKING | How Semi Trucks Slow Down Without Brakes | SCIENCE GARAGE

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When you let off the clutch in a manual- you can feel your car slow down. It’s called engine braking! It gives you more control over your car, but how does it work? Is it friction? And how is that different from the loud rumple of a diesel Jake Brake? We get into the differences between the two, and let you know if engine braking is good or bad for your engine!
Bart teaches us how cars work by blowing stuff up and cutting things in half. It’s a science show for the car lover who’s easily bored. Join Bart as he explains the science behind everything automotive. This is cars down to the atom. This is Science Garage.
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[@jacobg5122]

Science has shown that a Jake Brake is significantly quieter than an out of control truck crashing into your house.

[@thespeechboss]

Bruh

[@jacobg5122]

@@thespeechboss Do I be wrong though

[@SunnyG33]

True

[@froxxi668]

Depends on your house, dont think you hear much if it is just a standard american house

[@jmars]

😂

[@9Epicman]

We miss you Bart and science garage :(

[@dmuj3469]

We need science garage

[@waynegrape]

Science Garage! WHERE ARE YOU????

[@thewannabeweeb]

@@waynegrape he took a break because he had a child, he said this in a video about rolling coal, they deleted it though..

[@seddikibelgacem2393]

he is playing hide and seek

[@Gunnvulcan]

@@thewannabeweeb Why would they delete the video?

[@sharp640SR]

I miss science garage!!!! Definitely one of my favorites!

[@italengro197]

What happened? Why do I no longer see those type of videos? Did the actor leave donut?

[@josephgambino8306]

@@italengro197 I think so, if I recall correctly the host, Bart, had a child and is focusing on that. Don't know if he'll be back however.

[@Hakiri27]

I respect his decision, i hope he comes back though!

[@josephgambino8306]

@@Hakiri27 agreed

[@AC-vc5qp]

@@josephgambino8306 well actually he said if it was up to him he would still be there

[@Ricky-1]

Fact: every engine can get up to 15000 rpm at least once Edit: people are taking this joke to serious calm down

[@Ricky-1]

@@Ray-kg4dh I dont think you understand the joke so instead of saying r/woosh I will explain it every engine can get to 15000 rpm at least once because it will brake it

[@Ray-kg4dh]

Sorry for my stupidity, I get you now

[@user-xb2ig8yk4p]

Only once...maybe some break before reaching 15000rpm

[@jessemano9880]

@@user-xb2ig8yk4p not if its fast enough

[@sethmcclain255]

Mmm if the engine gets there before throwing a rod into space

[@EngineeringExplained]

KZbin is broken. My video released same time and also has no views, not visible in videos. Awesome KZbin!

[@JavierHernandez-fq4hu]

No u reeeeeeee

[@connorjohnson3098]

Engineering Explained have you taken it down I can’t see your video?

[@1970HondaCL100]

EE, I'm subscribed to you too and your video isn't showing up in my sub feed yet.

[@ladrepickens310]

ill watch it man. once it shows up of course.

[@devOnTheGo]

And was cursing my service provider

[@maz5miata269]

Holy hell. This dude can explain things so well. He's better than all of the teachers I've ever had.

[@SamHasACat]

I'd say something similar but nobody beats mr. Summa

[@LTV746]

Check out all of science garage . They’re amazing and funny

[@maz5miata269]

@@LTV746 Don't worry I have lol. Gonna be cool when Bart's back

[@patrickrusso4821]

My shop teacher just put science garage on half the time

[@rahulbiswas2993]

@@maz5miata269 he didn't 🥲

[@robm9772]

It is now June of 2021 and Bart with Science Garage was still the best show Donut did. Hope Bart is doing well over at Motor Trend but I miss him.

[@broodaiamdewey622]

Prob too manly for the donut crew

[@masterofjustice1984]

Coming up to a tunnel? It's Jake Brake O'clock.

[@Redbikemaster]

Dang straight

[@davecrupel2817]

😂 BRBRBRBRBRBRRBRBRBRBRBRBRBBRbrbrbbrbrbrbbr......

[@Ghilliebandits]

I hate how most of the new trucks have Jake brake noise dampeners so you can barely hear them

[@ant0n0vich]

A straight-piped Cat C15 has beautiful rumble! I always bring the thunder going through a tunnel.

[@Crayon3aterGaming]

@@ant0n0vich the C12 as well. The C7 is one of those engines with the noise reduction.

[@SonicBuxx]

i learn more from this than school thx sensei-donut for teaching me -life- about -cars- semi trucks

[@matthewtalafous2004]

I learned about this literally be hearing the truck

[@MostlyPennyCat]

That's funny. We were taught all this in middle school. That's ages 9 through 12. Four strokes, how a carburettor 4 cylinders engine works. Just as part of the countrywide standard curriculum. So everybody who was there but taught it as well. What did they teach you in America?

[@baerschuman111]

@@MostlyPennyCat mitochondria and shit

[@MostlyPennyCat]

@@baerschuman111 Fascinating aren't they? The evolution of prokaryotes into eukaryotes. One of our best hypotheses speculates that a mutant predator prokaryote ate a mutant prokaryote and formed a symbiotic relationship from their predator and prey relationship. The probability scale on which this was built is mind crushing. Billions of years and giga-trillions of interactions and we're decended from a handful of interactions that have a cell an advantage. Along cane photosynthesis, multicellular organisms and sexual reproduction. Primitive evergreens populated the pangean super continent along with the terrestrial animals and giant arthropods. Almost all of the coal we dig up was layed down during this 60 million year period at the end of the Devonian to the start of the Permian. I love me some megahistory. A lot of the history I learnt after I left school, what we see on TV and KZbin now were bleeding edge when you and I were at school.

[@minjaijung]

It’s Donut-sensei not sensei-Donut

[@NateTheNailer]

4 strokes of an engine: Suck Squeeze Bang Blow

[@doodskie999]

Just like my ex gf

[@mrpineapples4752]

EHEHEHEHE 😏😉

[@trent7736]

So can you tell us something we dont already know?

[@732JOK3R]

💦💦💦engines💦💦💦

[@nando03012009]

Dave Micolichek because the ex one was the freak. The “new one” AKA wife doesn’t do those things.

[@Jazoolee]

Can proudly say I binge watched all 49 videos in this playlist in a week or so...and learned a ton of stuff along the way... Thank you so much guys This playlist is a great way to get into the basics, loved it

[@djmaxxsaint]

Town Sound Ordinance: Keep quiet after 9 pm. Jake Brake: Hold my decibels.

[@RCFiddyOne]

Jacobs Brake - Pissing off city council members and HOAs one neighborhood as a time...

[@mitchanderegg5699]

RCFiddyOne 😂 you speak the truth

[@kalebbenson3528]

They banned it In small towns but it's good for the car.

[@thedegemeister3116]

the old jake

[@Neely26tv]

If they don't like it they can pack up and move

[@davecrupel2817]

And building one of the beat radial engines of alltime. The Jacobs R770.

[@Gleone58]

I was taught in transmission school that automatics even older style ones also have kindof an engine/trans brake. If youre going downhill and your brakes fade you can slam the trans from OD or D into L2 or L1 and it will actually apply extra bands and clutch packs and the engine will rev up to a certain rpm. But will not go further because the throttle is closed. Thats when the torque converter will compensate and slow the vehicle. The atf is cooled right after it leaves the converter to the trans cooler. You will not damage it. Ive tried that even on the poor 700r4 gm. It grabs the rear end and you slow down quick. So many people have died losing brakes going down a mountain and not knowing this engineered function of an automatic

[@simon-the-bar5657]

This is what the Chevy Volt does to recharge the battery. It's a technique by hybrid drivers to shift into Low to recharge the battery and slow the engine, very similar to engine braking in a manual

[@TheKaiTetley]

Thanks. I was wondering why I would use engine braking on my little Toyota Yaris.

[@BaconGod.]

​@@simon-the-bar5657I use that when I'm speeding and see a cop ahead to slow down quicker without applying the brake

[@samuelacheson5979]

I love how he explains it as if I'm a 5 year old. He really cares, it's like he genuinely wants people to know this information.

[@mikemartin6678]

I’m a truck driver and I love the new trucks jake brake, not the aerodynamic look, but the muffler is under the trucks so you can use your jake anywhere even where there are no engine brake signs because they don’t pop like stacks do (the exhaust pipes that go up and stick out over the truck) also the jake really has saved countless lives when it comes to steep mountains like West Virginia and PA

[@doctorstruts]

Ok who did the animations? The exhaust valve going up 😂👌

[@MyChevySonic]

As is the intake valve. Whoever did it doesn't understand engines.

[@doctorstruts]

@@MyChevySonic lol did not even notice that the intake did the same thing... But yeah probably should do some more reserch and checking before hand, i mean explaining hos stuff works and showing it wrong :')

[@z33tanner]

@@MyChevySonic Can you refer to an engine that pulls the valves up to open? That doesn't seem logical.

[@crazyeyez1502]

Or the diesel with a throttle body....

[@z33tanner]

@@crazyeyez1502 Another commentor pointed out modern diesel trucks sometimes do have a "throttle body" type device that creates more vacuum at specific loads for better emissions. Doesn't act as a throttle body more like an air brake. This one could slide but the valves... oh lord.

[@gener7MCpro]

i wish the diagrams were more accurate. for example the valves are opening the wrong way and even though it was stated that diesel engines dont have throttle bodies there was a throttle body on the diesel engine diagram. i hope no one gets confused by that kinda stuff

[@radualexandru6120]

not to mention the addition of a spark plug in a diesel engine ( 8:00)

[@z33tanner]

Same here the rpm gauge stayed the same as the speedo dropped arrrggg. Would have been nice to mention the torque converter separating the engine and trans hence why autos hardly engine brake.

[@igorchmielewski9152]

@@radualexandru6120 That's not a big deal, because there you have fuel injection. Looks quite the same ;-)

[@nicks6606]

@@radualexandru6120 no they say ignited by the heat, not by spark plug

[@MAXSOL69]

Radu Alexandru , that’s not a spark plug, it just an explanation produced by heat as it gets compressed

[@JamesBond-xx1lv]

How to slow down without hitting the brakes: Step 1: let off the gas.

[@EddieDaOnly1]

Diesel*

[@damirock98]

Won't work if you're going downhill

[@PlannedMayhem]

@@damirock98 low gears and it will.

[@eman7579]

PlannedMayhem not really. It will a little bit but diesels don’t have throttles so it’s going to suck air into the cylinders easy as could be

[@jacobg5122]

@@eman7579 That kind of braking is actually pretty hard on an automatic transmission because low rpms don't generate enough pressure to fully apply the clutches, meaning you'll have some engagement but still run the risk of slipping your clutches. Especially since the ones used for 1st gear are generally pretty small.

[@FCT8306onTwoWheels]

we miss Bart!

[@RonHaslam2001]

I never seen an engine valve open in this way 🤣🤣🤣🤣

[@BrandonPrentice]

I've been trying to wrap my head around jake braking for years..I'm used to doing it, but I never understood what it does to the engine. Thanks for the clear explanation!

[@seank5323]

Miss this series and this guy. A+ series

[@wickid13juggalo]

I miss Bart and the Science Garage. Seeing this again years later brought back many memories.

[@kevineldracher9422]

These were the best.

[@ItsMikeArre]

A colab between science garage and engendering explained is needed now!!!

[@brokkrep]

Engineering Explained?

[@thekenmatax18]

@@brokkrep No, engendering explained!

[@ye7170]

_colab_ _engendering_

[@tylerh629]

I think we all need this engendering explained

[@chrisi7127]

Ah yes, the politically correct series

[@benjamingomez7155]

Can we get some more videos on semis. Like DEF systems, air brakes, and axle weighs

[@ke8wlw]

Def "cleans" our exhaust, airbrakes rely on Chambers and axle weights for being legal is 12000 on the steers, 34k lbs on the drive tires and 34k lbs trailer tandems.

[@alextepozteco3681]

Both of these guys are wrong, DEF is made of synthetic urea, ammonia, and water that is sprayed via doser valve after the DPF(diesel particulate filter)into the SCR( Selective catalytic reduction) in order to bring down N0x levels for legal standards. They're extremely problematic since the beginning of their use. air brakes are for the most part are simple it's just a lot of valves that go into it, you're better off looking up some bendix or wabco air brake videos or doing some reading on how they work because theres too much detail to explain properly

[@karangill2945]

DEF system cleans our pockets too

[@johncurryb]

Karan Gill you got that right

[@killerrf]

Plus when burning off it consumes way more fuel than when it’s not burning off.

[@elgsquilliam]

This was the last episode of Science Garage! Crazy! It's been over a year and a half. In these last few episodes he definitely seems less energized.

[@ricardo_sarmiento]

maybe he knew that this was his last episode :(

[@DarioDAversa]

I’ve always used engine braking with my S4 and Stinger, and the later is even smoother because of the 8 speeds. Very often I slow down to the speed I want without even using my brake pedal. Nothing crazy, i.e. when getting out of the highway. Gives those brake pads more life!

[@bigqwertycat]

Brake pads are cheap. Engine/transmission parts are not.

[@Fools_Requiem]

@@bigqwertycat So, you didn't watch the video, I guess...

[@andreanastacio9548]

I`m sorry to be one of those ``ehm actually`` people, but as someone who studies mechanics here in europe, and who drives a (european) turbo diesel manual every day, i will say this much: engine braking DOES very much occur in diesel engines, just maybe not in the same way as in gasoline engines (and said engine braking is VARY noticable in both my car and in the vw transporter vans we have at work, especially in 1st and 2nd gear), and the phenomena that occurs in diesel engines may be known by a different name on your side of the ocean. In diesel engines, the car will slow down when you let off the gas because of the high compression. Basicly the cylinder will fill up with air and the piston will compress said air (high compresstion btw), but, because you dont want to accelerate, little to no diesel will be injected, and with no bang to push down the piston, aside from the compressed air, energy will be lost, rather than produced, and the car will slow down. A turbo helps in this sence because the residual boost will give the piston more air to compress without combustion, and, once boost is lost, there will also be a vacuum which will likely have a similar effect to what a petrol does. Also, from my experience with a 1.5l turbodiesel vs a 2.2l petrol, my diesel slows down my car more violantly than the 2.2l sedan my dad owned until recently. Also, the reason trucks use jake brakes or exaust brakes isn`t so much that the engine isn`t able to slow down the truck at all, but rather that the weight and inertia of the vehicle are to much for compression losses alone to slow it down significantly, and aditional restrictions need to be added to the exaust to further slow down the crankshaft. Again, sorry for being ``that guy`` but (as you could probably tell from my wordy comment) i didn`t agree with alot of what was said in the video, and wanted to share my viewpoint on the situation, since I felt you werent being truly fair to diesel engines in general. Keep up the good work though.

[@imkirbo3094]

You've answered the big question I was left with from this vid, thanks.

[@jakobkerber5357]

I also saw some diesels haveing throttles in the exhaust creating loads of backpreassure and thus slowing it down. of course if used to excessively this can destroy the engine very quickly.

[@andreanastacio9548]

Ok so the subject has been bothering me since i watched the video and wrote my first comment, and after reading the wiki page and a couple of forum posts about engine breaking i came to the following conclusion: diesel compression losses alone seem to not cause as much engine breaking as i had originally thought but while it is true that the compressed air will spring back, some of the energy WILL be lost in the form of heat to the water jackets and such, and if the engine is turbocharged, the turbo will also cause back preassure, making the pistons work harder to get the gases out, which means more breaking, not to mention (as i had originaly stated) an idle turbo will likely cause a slight vacuum on the intake manifold, and you know what that will do if you watched the video. Couple that with the different gearing (which plays a huge role on how the negative torque generated by the engine afects the vehicle) and you have a turbo diesel which, depending on who you ask, will engine break as well as a petrol.

[@andreanastacio9548]

Jakob kerber. Yeah it`s a commonly used system here for heavy trucks, instead of traditional jake breaks, but i doubt its a widespread system on passenger cars. What i do know is that some manufacturers do use something resembling throttle plates, although if is, as far as i understand, used primarily in conjunction with the egr for emissions purposes, but i doubt manufacturers would add a throttle plate and not use it to aid in engine braking. At any rate, even if diesels dont provide much braking on their own, the turbo adds more than enough restrictions to male up for it.

[@bengvideonagy]

Thank you I was about to ask why my 1.9tdi vw's engine brakes the car more than similar petrol engines I tried lol

[@hail2tfreeman]

So you're telling me they don't stop by dropping anchor?? Doubt

[@kleboskjervold-david8549]

Dhaval Bhawani you sir are the first comment to ever actually make me laugh!

[@RainytheNB]

Options; X doubt X doubt

[@Redbikemaster]

Let me tell ya. You leave that Jake on full blast and forget you're empty? It feels like an about drop lol

[@Texas_Cody]

Now explain modern "exaust brakes" in small diesel engines

[@markmann110]

Butterfly valve on the hot side of the turbo. Closes to create preassure in the engine. Kinda like the opposite of a throttle on a gas engine.

[@Redbikemaster]

Think of a throttle body but in your exhaust. Boom. Exhaust brake.

[@colinmatlock2164]

In applications where the engine has a VGT or variable geometry turbo the exhaust braking is controlled by the internal vanes of the turbo. Basically it closes the vanes as much as it can cause a large increase in drive pressure or back pressure in the exhaust manifold aiding in engine braking

[@stonedmountainunicorn9532]

Was wondering the same, my diesel car slows down a lot more then any gas car i ever drove, when i release the gas

[@davidaraujo2049]

Not just in small engines, actually here in Europe at least, the type of Jake brake he explains is less and less used, modern truck (what you call "rigs" in the USA) all use exhaust brakes witch go by many names like "retarder" or "mountain break". They are more efficient at breaking, therefore more safe

[@Kimmiesman24]

I have drove a truck for 8 years. Started watching your vids to learn about racing because i think that may be my next step. Cool that you covered this as well 😁

[@sv_russu]

Small correction, in gasoline engine the fuel will be completely cut off if you are above certain RPM (like 1500), so no “idling fuel air mixture happens, just air. Also, instead of the power stroke you just compress air which will not cause the power stroke, which also helps the braking. So, vacuum and pressure slows it down, not just vacuum.

[@nukeclears]

Actually no, the energy used compressing the air is spend on the downstroke. Only vacuum is slowing.

[@DROGOC0P]

​@@nukeclearsnot all of it. compression heat losses definetely help with braking

[@Fr4ncM]

*You:* _Jake brake_ *Me, as a 10yo intellectual:* _Look dad, truck farts! LOL_

[@davecrupel2817]

Oh my god 😂😂😂😂

[@nancyledesma7465]

You:Jake brake Me still 12:LOOK DAD A PETERBILT is snoring. It must be tired. No I’m just kidding.im actually 12 right now I’m with my dad going to drop of a load in Modesto

[@RubyXIII]

Nancy Jaime nice

[@Tonedog707]

Dude you been on KZbin for 13 years goddam

[@paytyler]

I did NOT just fart, I'm just running my jake brake.

[@digitalbilly]

This is so sad that Science garage is gone this was my favourite show... now I'm stuck watching reruns to get by in life.

[@user-oq9wt1us3v]

You guys should bring Bart back for a special episode. He’s the reason I fell in love with donut in the first place. He kinda taught me everything I understand about cars, he’s amazing

[@asinglelemon]

"that's a lot of Faygo" Michigan showing our reach

[@ryanwolfe911]

Modern diesels DO have throttle bodies, but they are primarily for emissions/ EGR functions. They still don't control throttle. The ECU by means of electrical motor or solenoid controlled vacuum line can control the actuation of the butterfly valve in the throttle body to restrict the amount of fresh air (from turbo charger) into the intake manifold under low engine load situations. This helps create a pressure differential and thus helps the EGR system to feed more exhaust into the intake manifold.

[@z33tanner]

Learn something new every day, interesting. Almost as functioning as a vacuum increasing butterfly, This plus variable geometry turbochargers is changing the game for all engines.

[@karlporath8904]

Which in reality the EGR still doesn't work properly. Like in my Freightliner. It has to have the carbon pushed out of the holes every 9-12 months. And let's not get started on the DEF system that drops my trucks mpg from 6.5 to 5.5 as soon as the temperature drops below 35f.

[@UncleDon226]

@@karlporath8904 the DEF shouldn't have an effect on fuel economy since it is all taking place downstream in the exhaust. Probably just seeing the effects of an engine running cooler than it's used to

[@CLardPercussion]

I love this. I've learned so much from your channel. Two years ago I was mechanicaly illiterate. Now I work on my own car and even shade tree for friends on simple things. Thank you KZbin University. And thank you donut team.

[@LonewolfeE5]

I love watching videos on things I already know about. I get more than just book knowledge about it and I get to hear different explanations of the same thing. It increases my knowledge a bit more every time. This video is well made and I'm glad it was recommended to me.

[@farmer8957]

Jake brake is the mating call of my people

[@evansorensen]

John Lutz all the semis are mating on the highway behind my house that means lol

[@brentmajor7784]

Word buddy

[@MaxSpeedMike]

Whoa, a late upload 👀 One of the best things about a manual transmission is engine braking. For daily driving, it's perfect

[@avalanche450]

I see you on every car related channel 😂 what a legend.

[@MaxSpeedMike]

@@avalanche450 lmaoo thanks bro!

[@basithph8958]

Good channel bro!

[@MaxSpeedMike]

@@basithph8958 thank you!! I got a hold of some badass cars recently. Reviews coming soon 👀

[@lydellthompson831]

Fucks with your channel bro.

[@aesir4330]

ive been watching videos in this channel since 2018, i was grade 8 student, and now im grade 12 graduating student, this gives me inspiration to pursue my course in college, im taking automotive servicing course, i wish you make more of this videos i will rewatch this videos as my reviewer....i learned a lot from this youtube channel, i love you science garage, i love you donut media

[@corvuscolbrand]

really miss this show, we actually watched these videos in my high school auto-shop class to learn the basics of a lot of stuff

[@ypnos1]

Absolutely great show. I wish you'ed been around when I was a kid with ZERO access to any info like this. Thanks dudes!

[@SuperSaiyan32]

BRING BACK BART AND SCIENE GARAGE! ME NEED TO KNOW MORE TO NOT MESS UP MY WHIP

[@mastershake2073]

I love u guys. Been watching y’all since middle school, when I started getting into cars. Now I’m getting ready to go into the navy as an Engineman.

[@tonycruz5450]

how’s it going so far?

[@andeluuledna]

Bart you will be missed, so does science garage :’)

[@timeless_2022]

What happened to Bart and is he the one speaking in the vid

[@andeluuledna]

@@timeless_2022 he left and joined Motor Trend

[@joshburke7176]

Thanks for this video! I have always wanted to know about this!

[@emmanuelopio3282]

Where's this guy now

[@JamesTM]

What an excellent explanation! I never understood why semi trucks made that obnoxious noise to slow down, while my manual car or bike was nice and quiet. Now I do!

[@azizithelethargic9229]

Where science garage? Bro everyone who watches car stuff are nerds/geeks, we need this. We WANT this.

[@MaxFluff]

jake brake is the best sound in the world

[@truckinon1871]

captain_fluff_ I agree especially The Detroit Deisel Series 60 or that 4 and a quarter Kitty Cat

[@THEFIRE360]

So what I got from this is that diesels engine brake by farting

[@sebasitanroberts2378]

I would say so

[@leanin7.3l24]

@@sebasitanroberts2378 Slipknot is bad satanic music.. You need Jesus.

[@sebasitanroberts2378]

@@leanin7.3l24 Your a disgrace to mankind

[@ghostgat4098]

@@sebasitanroberts2378 nice

[@pablomuzzobar8940]

A sexy fart

[@wifightit]

Love that last, uber-succinct line. Very clear. Great video!

[@SPRINCLES6]

Thank you for the video. I have studied this yet people still tell me a gasoline engine slows down from compression! I hope theyll be listening to you guys at least!

[@xwhels]

I feel like i am at physics class... You explain it like a hyped physics teacher

[@germangarciajr4249]

Donut, y’all should do more videos on semi trucks. The people need to be informed!! Also you should teach people how to drive around semi trucks. Its ridiculous the crap that people do. 🙄

[@nicemarmot3902]

Yea... Making a left turn as I start to go through a traffic light that turned green gets old especially since I can get moving quick from stopped. Or better yet someone makes a left as I'm making a right _as I'm entering the intersection_ to get in front of me.

[@germangarciajr4249]

The Wednesday Man for real. It is ridiculous.

[@truckinon1871]

German Garcia Jr Thank You German. I’ve been driving Semi’s for 20 years to the day. People don’t know how to drive around Semi’s and it needs to stop. We catch all the hell of a four wheeler not paying attention, trying to outrun a semi to get in front of the truck to catch an exit. Not knowing Semis have Bigger Blind Spots

[@nicemarmot3902]

@@truckinon1871 Here in PA they ran PSAs about it but it doesn't do anything. They need to make semi training mandatory to have a license renewed.

[@germangarciajr4249]

Truckin On Its not rare to se some of them run across 3 lanes of traffic and cutting you off trying to get the exit. Like why can you just start moving over in a safe manner ahead of time if you know your exit is approaching. 🙄

[@LunchBXcrue]

So basically its creating a vacuum that adds friction to the system thus slowing it down? Man what a time we live in, I literally heard the term "jake brake" 30 seconds ago and within 15 seconds I found an explanation on what it is! What a time to be alive, everything every little bit of info in the world is within arms reach.

[@enolopanr9820]

This video is top quality and has insane clarity 10/10 explanation

[@arez93]

I miss science garage :( it was so fun and interesting

[@genesisyoung141]

*my boy a lumberjack now*

[@thaddeusspendlove7437]

OfficialYoungGenesis the voice doesn’t quite fit

[@tahirriaz74]

thxs I am a CDL driver and I really needed this knowledge

[@asafegous]

My kids will enjoy the visual. Good job explaining Jake brake. You did forget to mention the displaced heat in the Jake process, though. Maybe in another video, then? Subscribing now.

[@michaelrainerii3547]

I've always loved Jake's. One of my favorite parts of driving a rig with straights. Preferably a Cat motor in a Kenworth W900L

[@ThunderingDiesel]

One of the reasons of why I want to become a trucker cause of that one time I saw a long nose Pete with loud ass jakes, now I’m finally getting my CDL and someday getting my dream pete

[@ineedmoneysp]

You can feel it in automatic cars that have a manual setting or paddle shifted. My car is automatic but I use the button shift sometimes especially if it is snowing out so I can control what gear the car is in better and to use engine braking so I can slow down without hitting the brakes and maybe losing control.

[@YourMom-nl4uw]

Same. My car has a dual clutch transmission, and it helps slow down ther car very well. Heck, sometimes I don't even have to use the brakes. The transmission slows me down enough.

[@naufalhafizhmuttaqin8503]

Bring back science garage The best and fun explanation

[@jmanj9379]

Your back!!!! Yayyyyyyyyy missed seeing you around my guy

[@Jirito0]

The little hand explosion when he hits the table😂😂

[@erroneum]

73000 lbs? Here in Michigan it's legal up to 164000 lbs. Also, some modern diesels actually do have throttles, but I'm pretty sure that's more to do with emissions (especially EGR) than anything. Also, automatics can engine brake Judy as well as a manual, they just need to have a lock-up torque converter

[@HIGHSTAROUTLAW]

Take a look at the highway trucks most of them will have a GVW on the side, so don't and I don't know why. Most of them you will see will be rated to 80,000. But because of having to spread the load out to keep axle weight low, 20,000 per single axle max here in Idaho, most are rarely to max. More than 80,000 and you are starting to get in to tanker/construction, doubles/triples, or the awe inspiring heavy haul.

[@codydonovan7356]

BRING BACK SCIENCE GARAGE!!! I miss this show. The best one on the channel

[@Okie-Tom]

Very good explanation of the jake brake! Thanks!

[@tinmanstavern]

I love that one jake video in that square dash peterbilt long hood Caterpillar is one of the best sounding imo Edit- I realized I commented when this first released 🤣

[@Redbikemaster]

In the original vid the owner says in the comments it's a Detroit

[@midgettiger6389]

Is it just me, or does Bart look buffer with a beard

[@jdm132]

MidgetTiger he does

[@finnkennedy2401]

Yes

[@monsterjambrony]

MidgetTiger Yes. I’m surprised more people didn’t bring this up.

[@ManofSexySteel]

Gettin Swol bruh

[@justdoit2521]

Bart means beard

[@johnmariano47]

A jake brake takes away the power stroke from the diesel engine which is a Compression Ignition type. The ignition or explosion otherwise suppose to happen is not happening because it does not meet the compression required for it to occur. Thus, there is no power coming from the engine even while the pistons are moving due to the kinetic energy of the truck. The pistons become passive and become a load with the whole engine as the tires on the road transmit the rotational force back to it with all the linkages. The popping sound is the external noise generated instead of the internal powerstroke. Thanks for your post. It is very informative and I enjoyed it a lot! Cheers!

[@WankenZeFurious]

Bart, you are the best teacher!

[@thedon7528]

FACT: WE WANT MORE SCIENCE GARAGE

[@StaelTek]

i am glad to see you have slowed down a bit and quit screaming all over the place. because of that, i subbed today.

[@RustyZipper]

“Cocaine, it’s a hell of a drug”

[@jeffunternaehrer8429]

Guys, please bring these back! ❤

[@KentuckyRanger]

That's why I love my 2015 Subaru Outback. The CVT uses virtual gears, so... When I want to slow down, I use the flappy paddles, and down shift to the lower ratios. I have a little over 60k miles on it, and the brakes look almost brand new...

[@sebastiansney4463]

Miss this type of videos

[@duckysingleton4712]

I'm in my Freightliner Cascadia right now looking at snow in Kansas!

[@truckinon1871]

duck duck Don’t feel bad I’m in a Volvo 670 in my own driveway looking at snow in Southeast Michigan.

[@Josedrift626]

Science garage is the best!!!! Keep up the great videos!

[@Young_Blueberry_]

I miss this so much we need this back!

[@microfarmers]

We diesel drivers can engine break without our Jake's, however it is less effective than a gas engine. During winter months when roads are slick we often avoid using our Jake's as they have a tendency to slide out our drives causing a jack knife. I like your analogy on the mechanics of the Jake break.

[@ceementality]

Yep cause jakes obly provide resistance to power axles

[@hungrymoose7627]

Trucker here. The reason that brakes can fail on trucks is because most of the trucks on the road in North America are drum brakes. As you apply the brakes the drum expands, and if you heat it up enough the drum will expand beyond the the stroke of the brake shoes and you literally have no brakes. The other failure that can happen is that if you apply constant, hard pressure to the brakes, you can heat them up so quickly that the components inside the brake drum and the wheel hub will catch on fire. Thankfully disk brakes are becoming more popular on class 8 trucks. Disk brakes can't get heat failure because the more the disk heats up the better they work. Of course you can still warp them or set them on fire, but with the better cooling its harder to do. Also runaway lanes work, but they're there to keep other drivers safe, not truckers. If you drive a truck up a runaway lane theres a very, very good chance you'll jackknife or flip.

[@burnoutbram5035]

As a European trucker I can't understand why you guys still run drum brakes. Here in Europe disc brakes is the standard for 20 years now ..

[@beefcakeandgravy]

@@burnoutbram5035 Fewer corners to slow down for.

[@khaliquet1]

@@burnoutbram5035 there are some vicious slopes here in the US Appalachian and Rocky Mountains

[@truckinon1871]

Hungry Moose Also we are getting more ultra shift transmissions (Automatics) as well

[@starwarrior125]

@@burnoutbram5035 Cost mostly. Trucking companies are generally notorious for cheaping out where they can.

[@jetnoise4817]

That was awesome! Always wondered about that… Thanks!

[@mwalker9401]

Thanks for the Bombfell ad! If I ever want shirts with sleeves that are 2" too short I'll check them out!

[@1970HondaCL100]

This video took an hour to show up in my subscription feed.

[@nztrucker1542]

Simple depending on how strong your Jake's pull back,weight and gradient of the hill and select the proper gear say 15% grade on my truck at 50T or 110k lbs I'd sit in 8th with Jake's on stage 3. Should hold at 1900rpm

[@trafficlightsid]

It's a good video for understanding how do engine brake work.. Thank you for the information..

[@Bobbydoesarchery]

How come there’s no new episodes for Science Garage? This is such a great series!

[@supergj7428]

When he said I’ll wait for you to subscribe I was going too but realized I already was, I didn’t know that

[@aldomaresca9994]

But the rpm andd the speed remain proportional always! As long as you keep the same gear ratio

[@aldomaresca9994]

Sorry, im that guy who spots mistakes

[@aldomaresca9994]

Aand i think the first prase should say disengage, not engage

[@thromboid]

I couldn't figure out why the speed and RPM wouldn't stay in proportion - glad to know it was a mistake in the video.

[@mcgrorymachined7596]

@@aldomaresca9994 and the valves move up in the diagrams, and the fact diesels engine brake even without jakes.

[@Bob_Lob_Law]

@Mykel Hardin Actually I think you're the douchebag.

[@treelance3464]

Went to trucking school, they never mentioned the engine/exhaust brake once. Great video!

[@ChuckisNorrish]

man this guy would be dad of the year. i’d let him drive me anywhere and ask so many questions

[@z33tanner]

Rpm gauge didn't move on the animation, in reality it will come down similarly with the rpm gauge not stay the same.

[@CanadianGods]

As a trucker engine braking is my best friend

[@jarrusjenkins]

Damn right it is.....

[@Wassenhoven420]

Mind explaining why? Is it safer, peace of mind type thing? Or are you driving a truck you own, so you are protecting your investment, such as brakes?

[@burnoutbram5035]

@@Wassenhoven420 if you only use the brakes on downhill they will overheat and you'll have a bad time...

[@CanadianGods]

@@Wassenhoven420 well its much safer to use engine brakes + regular brakes(stop sooner) also it's very good for protecting brakes, some times I dont even use the regular brakes at all.

[@burnoutbram5035]

Actually 90% of all breaking is slowing down and not stopping completely. With the modern engine brake technology and with a little bit of anticipation you only need the regular brakes to come to a complete stop or a more serious braking action. When I get out of my truck and get in my car I sometimes instinctly reach for the engine brake handle 🤣

[@air-headedaviator1805]

This video is a year old, but it would have been nice if they also covered automatic overdrive. I think thats the same thing, but I’m not aware of the differences. This is one of the best explanations I’ve seen.

[@Redtooth75]

Not the same, overdrive is just a gear with a ratio of less than 1:1

[@ashwanishahrawat4607]

Very well explained, Thank you very much.