On 04/12/2015 07:33 AM, Ed Pawlowski wrote:
Brake retarder is also known as an engine brake or "Jake Brake" as it
was developed by the Jacobs Engineering company.

Some communities forbid their use because they think it is more
important to be quiet than safe. The brake works by changing the valve
opening and closing during deceleration and it makes for a noisy
exhaust.Using the engine brakes saves the regular brakes and keeps them
from fading on a long hill. I've seen more and more of those signs
popping up nd I guess it will continue until there is a bad accident
from a truck losing its brakes.

The company I worked for had the real Jacobs setup on the newer trucks
and Blue Ox, which was just a plate restricting the exhaust on the older
trucks. The actuating cylinder on my truck failed. The shop mechanic
asked which way I was going and I said 'East.' "You won't need it back
East so we'll fix it when you get back." That's when I found some of
the grades in West Virginia are like driving off a cliff. They may not
be long, but they're steep and I missed the Ox.

Some of the big fleets save money by not installing the jakes. I17 from
Flagstaff to Camp Verde is a long grade and a guy was starting to lose
his brakes. I talked him down it, advising him to save what he had left
for some of the sharper curves. The road is straight north of Camp Verde
so I told him to just let it roll. The road goes back uphill after the
town so while you might be doing 90 at the bottom you'll be back down to
25 before you get to the summit.

I80 coming down the west side of Donner has a number of advisory signs
that are similar, when to gear down, when you're coming to a flat so you
can let it roll and so forth.

But they are noisy and the sleeping townies don't like 'Duh-dh-duh-duh'
at 3AM. Truthfully, there are few populated areas where you really need
the assist and it's just a courtesy to flip the switch off.