While traveling through Fredonia, Arizona earlier this month, I
saw a sign stating "NO JAKE BRAKES ALLOWED IN TOWN". None of
us in the vehicle could guess, so… what is a "jake brake"?
-Dan
–
Dan Romanenko Voice: (602) 581-4663 AG Communication Systems
Quality Engineering Fax: (602) 582-7111 P.O. Box 52179
UUCP: ….!{ncar!noao!enuucp | att}!gtephx!romanenkod Phoenix, AZ 85072-2179
Internet: gtephx!romanen…@enuucp.eas.asu.edu
I’ve been puzzled for some time by the signs that say "Use of
compression brake illegal within XXX city limits." I even asked a
trucker and he didn’t know. So what is a compression brake?
)_ _ ——————————————-
/ ) ) _ / Mark Baldwin – m…@sparky.nwra.com
/ / / / / /\_ /_/ Northwest Research Associates, Bellevue, WA
/ / /_(_/_/ (_/ \__ ——————————————-
In article <1992Aug20.164527.24…@gtephx.UUCP> romanen…@gtephx.UUCP (Dan Romanenko) writes:
>While traveling through Fredonia, Arizona earlier this month, I
>saw a sign stating "NO JAKE BRAKES ALLOWED IN TOWN". None of
>us in the vehicle could guess, so… what is a "jake brake"?
you should ask this on rec.autos.tech.
a jake brake, as i recall, is a compression brake. it’s used on
diesel engines, which have very high compression ratios (like 20:1).
thus, the engine compression acts to slow the vehicle.
there was a big war on rec.autos.tech about how this worked.
(somebody argued that compressing air was like compressing
a spring… the energy would be returned on the downstroke of
the piston. i don’t remember what the net consensus was, but it
seemed to me that some of that energy would be lost as heat.)
-teddy
romanen…@gtephx.UUCP (Dan Romanenko) writes:
>While traveling through Fredonia, Arizona earlier this month, I
>saw a sign stating "NO JAKE BRAKES ALLOWED IN TOWN". None of
>us in the vehicle could guess, so… what is a "jake brake"?
You ever hear a sound coming from a truck that sounds like a real
loud exhaust except the truck is slowing down instead of accelerating?
That’s a Jake Brake at work. It’s a compression release mechanism
that turns the engine into a very effective brake that does not
overheat and fade.
John
–
John De Armond, WD4OQC |Interested in high performance mobility?
Performance Engineering Magazine (TM) |
Marietta, Ga |Interested in high tech and computers?
j…@dixie.com |Write me about PE Magazine
Need Usenet public Access in Atlanta? Write Me for info on Dixie.com.
>In article <1992Aug20.164527.24…@gtephx.UUCP> romanen…@gtephx.UUCP (Dan Romanenko) writes:
>>While traveling through Fredonia, Arizona earlier this month, I
>>saw a sign stating "NO JAKE BRAKES ALLOWED IN TOWN". None of
>>us in the vehicle could guess, so… what is a "jake brake"?
I believe the reason they don’t want them used in town is because they’re
very loud. If you’ve ever spent any time around highways or interstates
you may have noticed a sudden loud noise that sounds like a Diamond Reo just
lost it’s muffler.
In article <1992Aug21.023606.11…@leland.Stanford.EDU> tedeb…@leland.Stanford.EDU (Theodore Chen) writes:
>In article <1992Aug20.164527.24…@gtephx.UUCP> romanen…@gtephx.UUCP (Dan Romanenko) writes:
>>While traveling through Fredonia, Arizona earlier this month, I
>>saw a sign stating "NO JAKE BRAKES ALLOWED IN TOWN". None of
>>us in the vehicle could guess, so… what is a "jake brake"?
>you should ask this on rec.autos.tech.
>a jake brake, as i recall, is a compression brake. it’s used on
>diesel engines, which have very high compression ratios (like 20:1).
>thus, the engine compression acts to slow the vehicle.
>there was a big war on rec.autos.tech about how this worked.
>(somebody argued that compressing air was like compressing
>a spring… the energy would be returned on the downstroke of
>the piston.
…unless you decided to open the exhaust value at about TDC, thus
releasing the pressurized air before it can force the piston back down.
NOTE: I’m not saying this is how it really works, since I’ve never heard
of a jake brake either.
In article <1992Aug20.164527.24…@gtephx.UUCP>, romanen…@gtephx.UUCP (Dan Romanenko) writes:
|> While traveling through Fredonia, Arizona earlier this month, I
|> saw a sign stating "NO JAKE BRAKES ALLOWED IN TOWN". None of
|> us in the vehicle could guess, so… what is a "jake brake"?
|>
|> -Dan
A "jake brake" is an engine braking system built by the Jacobs Brake Co, and
used on some diesel engines as a means of relieving the wheel brakes of some
of their work. Basically, it works on the valve train of the engine, allowing
the engine to act as a brake. When used, they can be quite loud, which is
why they are regulated in some municipalities.
This gets back to the discussion earlier this summer about engine braking in diesel
engines and shows that diesels, indeed, are poor brakes on their own. For
engine braking, diesels use either a jake brake, or some other valving done in
the exhaust circuit of the engine. Without these systems all braking must be
done by the brakes on the wheels, which can overheat quickly in loaded situations.
–
Alan Hepburn "An ignorant person is one who doesn’t know
National Semiconductor what you have just found out."
Santa Clara, Ca
a…@berlioz.nsc.com Will Rogers
The Jake brake intrigues me, could someone Email me more info on exactly how
it works?
Thanks!
________________________________________________________________________
Steven M. Knapp@ Iowa State University; Ames, IA
skn…@iastate.edu Computer Engineering Student
KA9…@N0AN.IA President Cyclone Amateur Radio Club
In article <1992Aug20.224946.29…@nwra.com> m…@nwra.com (Mark) writes:
>I’ve been puzzled for some time by the signs that say "Use of
>compression brake illegal within XXX city limits." I even asked a
>trucker and he didn’t know. So what is a compression brake?
I think by compression brake they mean downshifting and letting the engine
compression do the braking. Truckers almost always brake using this method and regular brakes. As for a Jake brake, I have no idea…
Mike
In article <1992Aug20.164527.24…@gtephx.UUCP> romanen…@gtephx.UUCP (Dan Romanenko) writes:
>While traveling through Fredonia, Arizona earlier this month, I
>saw a sign stating "NO JAKE BRAKES ALLOWED IN TOWN". None of
>us in the vehicle could guess, so… what is a "jake brake"?
They should outlaw those damn things EVERYWHERE…
Jake brakes are devices typically used (by my observation) by large
dump trucks (and others of that size, like cement trucks.)
I’m not sure exactly, but I believe they use the engine compression
to assist in slowing down the vehicle. Unfortunately, when engaged,
the things make an obnoxious zillion-decibel truck type sound.
I think the truckers think they’re "cool" or something. Where I live
in Maryland, it seems like they ALL have them, and they try to hop
up their trucks by adding chrome and painting stupid things on the
back like: "Flights of Fancy", "U N V Me", and the like. (Not kidding.)
Never fails to elicit tons of laughter when I see a new slogan.
–
j…@access.digex.com | (Cage) 1998 323se (ZCP-710) | Comus Road
Merry Land (MD) U.S.A. | (Bike) 1986 GSXR750 (sold) | ClarksBURG
——————————————————————————
But of course, I have three eyes. I have clairvoyant paranoia. -King Missile
Since the definition of a jake break has already been offered (good
definition, by the way), I just wanted to add a point in favor of them.
Sure, some drivers may use them and try to seem cool, but as a driver, I
have to say that without them, you would see far more instances of run away
trucks from overheated wheel brakes. Jakes work either alone or combined
with the air brakes on the trailor and tractor, and have saved many
situations, especially in the west where we have real mountains.
It is a brake which uses engine compression to decelerate. It has the
characteristically loud sound associated with trucks going down hill.
(It sounds somewhat like removing the muffler). This is just one of
several braking systems on a truck. Using the jake brake saves the
brake pads from overheating.
In article <1992Aug22.170200.11…@access.digex.com>, j…@access.digex.com (Jim Brooking) writes:
|>
|>
|> They should outlaw those damn things EVERYWHERE…
|>
|> Jake brakes are devices typically used (by my observation) by large
|> dump trucks (and others of that size, like cement trucks.)
|>
|>
…and when a cement truck hauling 10 yards of wet cement rolls over your
little putt-putt at the bottom of a loooooooong 6 1/2% down grade because
his wheel brakes have overheated and faded you’ll be saying "why didn’t you
use your Jake brake?". I would not drive a truck without a Jake brake, or
some other type of compression braking, because I know that the wheel brakes
are not enough when you’re trying to keep a large vehicle under control.
My F350 pickup has a compression brake on it because I tow a fifth wheel and
the combined weight of truck and trailer is 16,000 lb. If I were to rely on
my wheel brakes to control my speed on down grades I’d be at the bottom of
the grade a lot faster than I’d like, unless the brakes caught fire.
–
Alan Hepburn "An ignorant person is one who doesn’t know
National Semiconductor what you have just found out."
Santa Clara, Ca
a…@berlioz.nsc.com Will Rogers
From article <l98ddqINN…@jethro.Corp.Sun.COM>, by geo…@purplehaze.Corp.Sun.COM (Geoff Miller):
- Hide quoted text — Show quoted text -
> In article <1992Aug20.164527.24…@gtephx.UUCP> romanen…@gtephx.UUCP
> (Dan Romanenko) writes:
>>While traveling through Fredonia, Arizona earlier this month, I
>>saw a sign stating "NO JAKE BRAKES ALLOWED IN TOWN". None of
>>us in the vehicle could guess, so… what is a "jake brake"?
> It’s a feature on large diesel trucks that creates engine braking power
> by (I believe) shutting off fuel and turning the engine into an air pump;
> they’re very noisy, hence the prohibition you cite. You might recall
> having heard a loud burst of noise from a semi going downhill, sort of a
> BRRRRRRRRRRRRRRRRT! sound. That’s a jake brake in action. Don’t know
> where the name comes from, though.
The name comes from Jacob’s Brake. I think this the Company that first
started making them.
robert
—
Best regards Robert.
__________________________________________________________________________
Robert Krohn (M.S 16-320) robe…@nsc.nsc.com
In article <1992Aug26.144306.28…@berlioz.nsc.com> a…@lancaster.nsc.com (The Hepburn) writes:
>In article <1992Aug22.170200.11…@access.digex.com>, j…@access.digex.com (Jim Brooking) writes:
>|>
>|>
>|> They should outlaw those damn things EVERYWHERE…
>|>
>|> Jake brakes are devices typically used (by my observation) by large
>|> dump trucks (and others of that size, like cement trucks.)
>|>
>|>
>…and when a cement truck hauling 10 yards of wet cement rolls over your
>little putt-putt at the bottom of a loooooooong 6 1/2% down grade because
>his wheel brakes have overheated and faded you’ll be saying "why didn’t you
>use your Jake brake?".
No… I’d say, "Why don’t you get a good lawyer, ’cause you’re gonna need
one." (Assuming I survived) I’m sick & tired of seeing idiot
truck drivers hauling ass with a full load and driving like general
morons… Every couple of months around here one of those
dump-truck-driving Mario Andretti wannabes gets into a (usually) fatal
rear-end collision with a 4 wheeler. Not bright.
My problem with jake brakes is purely the fact that they can be heard for
several miles. I don’t believe noise is necessary for good braking…
–
j…@access.digex.com | (Cage) 1991 323se ZCP-710 | Comus Road
Merry Land (MD) U.S.A. | (Bike) 1986 GSXR750 (sold) | ClarksBURG
——————————————————————————
But of course, I have three eyes. I have clairvoyant paranoia. -King Missile
In article <1992Aug26.170906.23…@access.digex.com> j…@access.digex.com (Jim Brooking) writes:
>>…and when a cement truck hauling 10 yards of wet cement rolls over your
>>little putt-putt at the bottom of a loooooooong 6 1/2% down grade because
>>his wheel brakes have overheated and faded you’ll be saying "why didn’t you
>>use your Jake brake?".
>No… I’d say, "Why don’t you get a good lawyer, ’cause you’re gonna need
>one." (Assuming I survived) I’m sick & tired of seeing idiot
excellent mentality.
>truck drivers hauling ass with a full load and driving like general
>morons… Every couple of months around here one of those
>dump-truck-driving Mario Andretti wannabes gets into a (usually) fatal
>rear-end collision with a 4 wheeler. Not bright.
every thirty seconds a passenger-car-driving wannabee gets into a
(usually) fatal rear-end collision with another 4 wheeler. Not bright.
>2. My problem with jake brakes is purely the fact that they can be heard for
>several miles. 1. I don’t believe noise is necessary for good braking…
Well, 1. You’re wrong and 2. Who cares.
In article <1992Aug28.032657….@tamsun.tamu.edu> mds8…@tamuts.tamu.edu (Michael David Slater ) writes:
>>2. My problem with jake brakes is purely the fact that they can be heard for
>>several miles. 1. I don’t believe noise is necessary for good braking…
>Well, 1. You’re wrong and 2. Who cares.
Wrong? There are lots of heavy vehicles which brake just fine without
disturbing every living being within a 10 mile radius. Loud bad-ass
Jake Brakes are the exception rather than the rule.
Who cares? Obviously several localities care enough to make their use
illegal…
–
j…@access.digex.com | (Cage) 1991 323se ZCP-710 | Comus Road
Merry Land (MD) U.S.A. | (Bike) 1986 GSXR750 (sold) | ClarksBURG
——————————————————————————
But of course, I have three eyes. I have clairvoyant paranoia. -King Missile
- Hide quoted text — Show quoted text -
j…@access.digex.com (Jim Brooking) writes:
> In article <1992Aug26.144306.28…@berlioz.nsc.com> a…@lancaster.nsc.com (T
> >In article <1992Aug22.170200.11…@access.digex.com>, j…@access.digex.com
> >|>
> >|>
> >|> They should outlaw those damn things EVERYWHERE…
> >…and when a cement truck hauling 10 yards of wet cement rolls over your
> >little putt-putt at the bottom of a loooooooong 6 1/2% down grade because
> >his wheel brakes have overheated and faded you’ll be saying "why didn’t you
> >use your Jake brake?".
> No… I’d say, "Why don’t you get a good lawyer, ’cause you’re gonna need
> one." (Assuming I survived) I’m sick & tired of seeing idiot
> truck drivers hauling ass with a full load and driving like general
> morons… Every couple of months around here one of those
> dump-truck-driving Mario Andretti wannabes gets into a (usually) fatal
> rear-end collision with a 4 wheeler. Not bright.
FYI… Most truck drivers, when filling out job applications, will come across
a section like:
Accidents in the past 10 years:
Fatalaties in the past 10 years:
^^^^^^^^^^
For that matter, a truck driver has to go to school for several months, and
to get their CDL they have to actually prove they can handle what they’re
driving. (I mean backup and park, not just motor around the block). Then,
of course, is the mandatory drug testing, the bi-annual physicals…
As far as Mario wannabes, I don’t know how many times I’ve seen a truck
trying to follow a car at a safe distance, only to have car after car
cut into his cushion, forcing him to back off farther.
> My problem with jake brakes is purely the fact that they can be heard for
> several miles. I don’t believe noise is necessary for good braking…
Any engine converts energy from one form to another. A gasoline engine
converts potential energy into motion. A brake system converts motion
into something else… Friction brakes convert motion into heat. Problem is,
after a while you glaze the brake shoes, the friction coefficient goes down,
and they loose effectiveness. A jake brake system uses the diesel engine
as a compressor, converting speed into potential energy as compressed air,
which is then released, converting the energy to noise.
–
Dean Woodward | OK. Last time. This is my machine. This is my
d…@fringe.rain.com | Opinion. This is my opinion on my machine.
Any Questions? -me
d…@fringe.rain.com (Dean Woodward) writes:
Any engine converts energy from one form to another. A gasoline engine
converts potential energy into motion. A brake system converts motion
into something else… Friction brakes convert motion into heat. Problem is,
after a while you glaze the brake shoes, the friction coefficient goes down,
and they loose effectiveness. A jake brake system uses the diesel engine
as a compressor, converting speed into potential energy as compressed air,
which is then released, converting the energy to noise.
Agreed except that you do not have to make noise. All you need is a good
muffler. The muffler for normal driving is designed for deriving condition
and is not good enough for breaking. I guess when "jake brake" is banned by
enough localities you will see better mufflers.
In article <1992Aug26.170906.23…@access.digex.com>, j…@access.digex.com (Jim Brooking) writes:
|> In article <1992Aug26.144306.28…@berlioz.nsc.com> a…@lancaster.nsc.com (The Hepburn) writes:
|> >
|> >…and when a cement truck hauling 10 yards of wet cement rolls over your
|> >little putt-putt at the bottom of a loooooooong 6 1/2% down grade because
|> >his wheel brakes have overheated and faded you’ll be saying "why didn’t you
|> >use your Jake brake?".
|>
|> No… I’d say, "Why don’t you get a good lawyer, ’cause you’re gonna need
|> one." (Assuming I survived) I’m sick & tired of seeing idiot
|> truck drivers hauling ass with a full load and driving like general
|> morons… Every couple of months around here one of those
|> dump-truck-driving Mario Andretti wannabes gets into a (usually) fatal
|> rear-end collision with a 4 wheeler. Not bright.
It’s been my experience that a lot of those type of accidents are, in fact,
caused by the wannabees in the roller skates who decide at the last possible
moment that they want to occupy the space in front of the truck. I’ve driven
many, many miles and have had some real winners try some really interesting
manoeuvres in my vicinity. I’m not saying it’s all the car driver’s fault; I
agree taht you will find drivers of all types of vehicles that manage to find
the driver’s license window at the local Salvation Army. But what a lot of
drivers don’t think about is the stopping distance required by a fully-loaded
truck. Government de-regulation has’t helped either. In the past it took a
lot to get a job driving. Now everybody with the down payment can go out and
buy a truck and start driving. The overall experience level has dropped
alarmingly, and with it a rise in accidents has been seen. But to blame the
truck driver for all rear-end type accidents is simplistic, at best.
|>
|> My problem with jake brakes is purely the fact that they can be heard for
|> several miles. I don’t believe noise is necessary for good braking…
|>
Yes, they are loud. But that energy has to be converted to something.
Converting to heat is what the wheel brakes do, and you can only dissipate
so much heat. And I would rather hear a jake brake doing its job than a
motorcycle wound out to 12 grand on a city street.
–
Alan Hepburn "An ignorant person is one who doesn’t know
National Semiconductor what you have just found out."
Santa Clara, Ca
a…@berlioz.nsc.com Will Rogers
In article <29aaqB4w1…@fringe.rain.com>, d…@fringe.rain.com (Dean Woodward) writes:
|> j…@access.digex.com (Jim Brooking) writes:
|>
|> FYI… Most truck drivers, when filling out job applications, will come across
|> a section like:
|>
|> Accidents in the past 10 years:
|> Fatalaties in the past 10 years:
|> ^^^^^^^^^^
|>
|> For that matter, a truck driver has to go to school for several months, and
|> to get their CDL they have to actually prove they can handle what they’re
|> driving. (I mean backup and park, not just motor around the block). Then,
|> of course, is the mandatory drug testing, the bi-annual physicals…
For those who haven’t tried for a CDL (Class A in Calif) there are 2 written
tests, and a road test that takes over an hour. You make an appointment to
take the written tests. You bring with you a medical form signed by your
doctor, after he has given you a complete physical. If you pass both written
tests you can make an appointment for the road test. For the road test you
must show up in the type of vehicle you want to be licensed for: ie if you
want to haul duals you better have both trailers with you. The first step in
the road test is to convince the examiner that you know how to safety check
your vehicle. The examiner will follow you as you check all tires, brakes,
cables, chains, etc. Then you start driving. The first thing you must do is
to pull forward to a line drawn on the roadway. You lose 1 point for every 6
inches that your front bumper is short of, or over, that line. Then you must
back up between 2 rows of cones, without touching a cone, for a distance of
50 feet. Then you hit the road. You are observed on city streets, highways,
in all types of traffic conditions.
Even with this testing it is common for drivers with an attitude to get their
license. And with costs rising almost exponentially, it is very tempting for
younger drivers to try and make ends meet by exceeding their allotted driving
time. But overall, I would rather drive with a pack of truckers than a pack of
yuppie car drivers.
–
Alan Hepburn "An ignorant person is one who doesn’t know
National Semiconductor what you have just found out."
Santa Clara, Ca
a…@berlioz.nsc.com Will Rogers
In <29aaqB4w1…@fringe.rain.com> d…@fringe.rain.com (Dean Woodward) writes:
>j…@access.digex.com (Jim Brooking) writes:
>> In article <1992Aug26.144306.28…@berlioz.nsc.com> a…@lancaster.nsc.com (T
>> >…and when a cement truck hauling 10 yards of wet cement rolls over your
>> >little putt-putt at the bottom of a loooooooong 6 1/2% down grade because
>> >his wheel brakes have overheated and faded you’ll be saying "why didn’t you
>> >use your Jake brake?".
>> No… I’d say, "Why don’t you get a good lawyer, ’cause you’re gonna need
>> one." (Assuming I survived) I’m sick & tired of seeing idiot
>> truck drivers hauling ass with a full load and driving like general
>As far as Mario wannabes, I don’t know how many times I’ve seen a truck
>trying to follow a car at a safe distance, only to have car after car
>cut into his cushion, forcing him to back off farther.
I am constantly amazed at the number of times I see a truck leave
a nice gap in front coming up to traffic lights, only for some moron
in a car change lanes into the truck’s braking area. It would not be
uncommon for a truck to lose 10 or 15 metres of braking area this way.
People don’t seem to realize that all that kinetic energy cannot be
just thrown away. Having a truck license (not often used) I know of
what I speak, and the temptation to ram the car that does it is very
powerful – as in NSW you are almost certain to get away with it.
thos
—
thos cohen |Softway Pty Ltd
The best way to make a Japanese engineer wince|ACSnet: t…@softway.oz
is (when talking about an NSX) to say slowly |UUCP: …!uunet!softway.oz!thos
’but its _not a Ferrari_ is it?’ R.Bulgin, CAR|Internet: t…@softway.oz.au
In article <thos.715317…@suite.sw.oz.au>, t…@suite.sw.oz.au (Thomas Cohen) writes:
|> I am constantly amazed at the number of times I see a truck leave
|> a nice gap in front coming up to traffic lights, only for some moron
|> in a car change lanes into the truck’s braking area.
Trucks and cars on the same road is a poor mixture. In the governments’
typical way of getting things upside down trucks are ofter banned from the left
or "fast" lane of interstate. A real blue ticket ride in the Washington DC area
is to try to get to an exit when the right two lanes are crowded with trucks.
Lets give the left lane to the trucks, especially the thru traffic.
In article <1992Aug26.144306.28…@berlioz.nsc.com> a…@lancaster.nsc.com (The Hepburn) writes:
>…and when a cement truck hauling 10 yards of wet cement rolls over your
>little putt-putt at the bottom of a loooooooong 6 1/2% down grade because
>his wheel brakes have overheated and faded you’ll be saying "why didn’t you
>use your Jake brake?". I would not drive a truck without a Jake brake, or
>some other type of compression braking, because I know that the wheel brakes
>are not enough when you’re trying to keep a large vehicle under control.
Why not put a muffler on the Jake brake? The Jake brake is almost as
load as unmuffled engine exhaust.
Bob Hale …!ucsd!btree!hale
…!btree!h…@ucsd.edu …!ucsd!btree!h…@uunet.uu.net
The Jake brake is a braking system manufactured by the Jacobs Equipment Company.The company manufactures units which attach over the cylinder heads on diesel
engines using cam actuated injectors. When engaged it couples the injector
motion to the exhaust valve opening it at the top of the compression stroke
and releasing the compression pressure in the cylinder. Doing this makes quite
a bit of noise which is why some miunicipalities ban the use of them inside
their limits.
Roger Mitchell
Master Mechanic: Ft. Collins Municipal Railway