platinum01
Full Access Member
Good One
That was a good one. Almost looked professional. LOL
Still nice.
That was a good one. Almost looked professional. LOL Still nice.
What is a jake brake?
- Thread starter bling821
- Start date
CHPMustang
Senior Member
My 2001 DT466 came with a Jacobs medium duty engine brake which I usually left on most of the time,just a tap of the service brake and it'd stay at the posted truck speed going down the I-5 Grapevine or Donner Summit 
A must on B & A trucks!
A must on B & A trucks!
Scot
;()
Michigan trucks really need the brake even without steep grades.
Michigan permits trucks up to
164,000 pounds on the system. However, different than other states, Michigan requires a lower weight per axle which more evenly distributes the load and reduces wear and tear on roads. MDOT engineers have thoroughly studied this issue and the result of this research is that heavier trucks do not cause a disproportionate amount of damage as long as the weight is evenly distributed over an appropriate number of axles. Additionally, trucks over 80,000 pounds make up only less than 5% of all trucks operating on our roads. If Michigan were to reduce it's truck weight laws to 80,000 pounds, more damage to the system may occur because of the need to put more trucks on the road. More trucks on the road raise serious questions concerning safety and traffic congestion. Several other states are currently looking at Michigan's axle weight laws and are considering adopting similar laws.
"this is a Cut and Paste"
Michigan permits trucks up to
164,000 pounds on the system. However, different than other states, Michigan requires a lower weight per axle which more evenly distributes the load and reduces wear and tear on roads. MDOT engineers have thoroughly studied this issue and the result of this research is that heavier trucks do not cause a disproportionate amount of damage as long as the weight is evenly distributed over an appropriate number of axles. Additionally, trucks over 80,000 pounds make up only less than 5% of all trucks operating on our roads. If Michigan were to reduce it's truck weight laws to 80,000 pounds, more damage to the system may occur because of the need to put more trucks on the road. More trucks on the road raise serious questions concerning safety and traffic congestion. Several other states are currently looking at Michigan's axle weight laws and are considering adopting similar laws."this is a Cut and Paste"
Scot
;()
Michigan trucks really need the brake even without steep grades.
Michigan permits trucks up to 164,000 pounds on the system. However, different than other states, Michigan requires a lower weight per axle which more evenly distributes the load and reduces wear and tear on roads. MDOT engineers have thoroughly studied this issue and the result of this research is that heavier trucks do not cause a disproportionate amount of damage as long as the weight is evenly distributed over an appropriate number of axles. Additionally, trucks over 80,000 pounds make up only less than 5% of all trucks operating on our roads. If Michigan were to reduce it's truck weight laws to 80,000 pounds, more damage to the system may occur because of the need to put more trucks on the road. More trucks on the road raise serious questions concerning safety and traffic congestion. Several other states are currently looking at Michigan's axle weight laws and are considering adopting similar laws.
"this is a Cut and Paste"
Michigan permits trucks up to
164,000 pounds on the system. However, different than other states, Michigan requires a lower weight per axle which more evenly distributes the load and reduces wear and tear on roads. MDOT engineers have thoroughly studied this issue and the result of this research is that heavier trucks do not cause a disproportionate amount of damage as long as the weight is evenly distributed over an appropriate number of axles. Additionally, trucks over 80,000 pounds make up only less than 5% of all trucks operating on our roads. If Michigan were to reduce it's truck weight laws to 80,000 pounds, more damage to the system may occur because of the need to put more trucks on the road. More trucks on the road raise serious questions concerning safety and traffic congestion. Several other states are currently looking at Michigan's axle weight laws and are considering adopting similar laws."this is a Cut and Paste"
cut and paste or not it was an educational reminder even
to us that were some what familar w/ 'em.
ok so jake brakes hold the exhaust valve open (and shut off the
fuel)...now for more details (cut and paste if you can find it i dont
care in a mechanical (injection) diesel how do they shut the fuel
off. (from what i read on the JACOBS site, i dont see any mention
of the fuel being shut off...infact i think thats the problem, where
all the noise comes from...it looks like the open the valve "prematurely"
reducing the "power" on the compression stroke)
and i didnt realize that there are more than one setting for the
jake brakes (whats the difference between the settings...do they
open the exhaust valve more ?)
look here for more details and pictures (i like pictures on how
the different "engine" brakes work... JACOBS Vehicle Systems
to us that were some what familar w/ 'em.
ok so jake brakes hold the exhaust valve open (and shut off the
fuel)...now for more details (cut and paste if you can find it i dont
care
in a mechanical (injection) diesel how do they shut the fuel off. (from what i read on the JACOBS site, i dont see any mention
of the fuel being shut off...infact i think thats the problem, where
all the noise comes from...it looks like the open the valve "prematurely"
reducing the "power" on the compression stroke)
and i didnt realize that there are more than one setting for the
jake brakes (whats the difference between the settings...do they
open the exhaust valve more ?)
look here for more details and pictures (i like pictures
on how the different "engine" brakes work... JACOBS Vehicle Systems
BamaSixGun
SDD Super Mod/Staff
bushpilot said:
on our trucks, they have a low, medium, and high setting. depending on traffic conditions you may just keep it on a low or medium setting, and if your goin down steep grades/inclines, you would keep it on high setting.
to make it very simple, all that a jake brake does is allows you to save the brakes on the truck/trailer by assisting with slowing down the engine. it really doesn't matter about the technical aspects of its mechanics, it just helps to slow down 80,000 lbs alot easier.
plus it does sound very cooool if you like loud noises.
BamaSixGun
SDD Super Mod/Staff
bush, from what little i know (without cut & paste) , the piston is still trying to do its job, while the valves are tryin to stay closed, to reduce the power of the engine, from what i understand, thats where the noice comes in.
*****please refer to my cut & paste article above, if what i just said is wrong*****
, the piston is still trying to do its job, while the valves are tryin to stay closed, to reduce the power of the engine, from what i understand, thats where the noice comes in.*****please refer to my cut & paste article above, if what i just said is wrong*****
stephen understand...
the piston travel is REDUCED in its force from the
premature exhaust valve opening...from what i can tell (from
the details on jakebrake.com) the only thing that the
jake brake does is hold the exhaust valve open (i dont read
that fuel is shut off)...
the sight lacks details in the low/med/high settings...i DOUBT
the settings open the valve MORE (danger of piston contact)...
its my own question but it seems more "logical" that the
switch would probably open the exhaust valve EARLIER (during
the compression stroke) in the HIGH setting (compared to low or
medium)
i read about retro fitting the system and all they do is add the
mechanical (exhaust) valve "opener" two switches (one on the clutch
pedal to disable the jake brake) and one on the dash to select
the jake brake (on/off etc)
theres no mention of any "shut off" of the fuel...if they shut off
the fuel (when the jake brake was powered ON) the truck would
basically STALL or at best the exhaust sound would be nothing but
AIR (instead of the pop pop pop...)
im not saying anyones wrong...your post was great...and i was
curious for more detail...
the piston travel is REDUCED in its force from the
premature exhaust valve opening...from what i can tell (from
the details on jakebrake.com) the only thing that the
jake brake does is hold the exhaust valve open (i dont read
that fuel is shut off)...
the sight lacks details in the low/med/high settings...i DOUBT
the settings open the valve MORE (danger of piston contact)...
its my own question but it seems more "logical" that the
switch would probably open the exhaust valve EARLIER (during
the compression stroke) in the HIGH setting (compared to low or
medium)
i read about retro fitting the system and all they do is add the
mechanical (exhaust) valve "opener" two switches (one on the clutch
pedal to disable the jake brake) and one on the dash to select
the jake brake (on/off etc)
theres no mention of any "shut off" of the fuel...if they shut off
the fuel (when the jake brake was powered ON) the truck would
basically STALL or at best the exhaust sound would be nothing but
AIR (instead of the pop pop pop...)
im not saying anyones wrong...your post was great...and i was
curious for more detail...
BamaSixGun
SDD Super Mod/Staff
i believe lee, AKA MUDWHISTLE, who is a CAT tech out in OR or WA could help us out on this some.
as far as the techincal terms, you are way over my head bush. as fas as the exacts of what is happening in the engine/jake brake dept., it really doesn't matter, its overall design is to slow the engine down, thus, slowing the vehicle down, thus saving your brakes.
sometimes we can get to caught up in the particulars, na mean ?
as far as the techincal terms, you are way over my head bush. as fas as the exacts of what is happening in the engine/jake brake dept., it really doesn't matter, its overall design is to slow the engine down, thus, slowing the vehicle down, thus saving your brakes.
sometimes we can get to caught up in the particulars, na mean ?
