Peterbilt 579 Operator's Manual page 205

Driving Bobtail or with an Unloaded
Trailer
We recommend that you do not use
your engine retarder to slow down
when you are bobtailing or pulling an
empty trailer.
WARNING!
Using an engine retarder can cause a
wheel lockup. The trailer is not load-
ing the tires enough to give the traction
you may need. When you are bobtail
or unloaded, you can have a serious
accident if your wheels lock suddenly
during braking. You could be killed or
injured. Don't use your retarder when
you are driving bobtail or with an un-
loaded trailer.
(04/13)
Transmission Retarder
If you have this option, it will act
like a brake to slow your vehicle
without using the brakes. Take your
foot off the throttle and operate the
retarder switch. When you do not
need full retarder effect, you can
apply it intermittently (off and on)
to cause gradual or partial slowing.
Continuous application of your retarder
will cause your hydraulic fluid to get
hotter. Intermittent application will help
prevent overheating.
Y53-6047–2C
OPERATING THE BRAKE SYSTEM
WARNING!
Do not rely on your automatic trans-
mission hydraulic retarder to stop your
vehicle. If your engine shuts down, the
vehicle's retarder will cease to operate
which may lead to an accident involv-
ing death or personal injury. Always
be ready to suddenly apply the service
brakes.
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