[TR] Jake Brake: was 'free wheeling'

[Michael Porter]

Randall wrote:
>> This close to being right?
>>     
>
> However, "Jake Brake" is a brand name, and that company offers many newer
> designs that aren't as noisy, so there has been a certain amount of
> controversy on the subject.
>
>   

The water-cooled braking referred to was probably a water-powered 
retarder, which were commonly attached to the third member on early 
trucks, and operated much like a water-powered dynamometer.  Today, with 
electronic diesel injection, Jakes are often external to the engine--a 
strong solenoid actuates a plate that closes off the exhaust, with the 
same signal turning on the solenoid shutting off the injectors.  The 
effect is much the same, and noise, while still considerable, is muffled 
by the air cleaner, since the air entering the engine is shunted back up 
through the intake.


Most auxiliary braking today is done with retarders on the transmission, 
operating somewhat like the old water brakes, but using, instead, ATF 
under pressure as the medium between oppositely rotating sets of vanes 
at the trans output.


Cheers.

-- 


Michael Porter
Roswell, NM


Never let anyone drive you crazy when you know it's within walking distance....