Specifications

STARTING AND OPERATING THE VEHICLE VEHICLE RECOVERY AND SPRING BRAKES
Medium Duty
(R05/09) Y53-6008A – 139 –
2. Into the inter-axle differential, add 2 pints (.94 liter) of
approved lubricant.
• See “Recommended Lubrication Types,” Page
136
.
3. After adding the specified type and amount of lubri-
cant, drive the vehicle. It should be unloaded. Drive 1
to 2 miles (1.5 to 3 km) at a speed lower than 25 mph
(40 km/h). This will thoroughly circulate the lubricant
through the assembly.
Spring Brakes — Manual Release
In order to tow a vehicle, if there is insufficient air to
release the parking brake, the spring brakes can be man-
ually released.
WARNING! Do not drive vehicle with malfunc-
tioning brakes. If one of the brake circuits
should become inoperative, braking dis-
tances will increase substantially and han-
dling characteristics while braking will be
affected. You could lose control of your vehi-
cle, be severely injured, or cause an accident.
Have it towed to the nearest dealer or quali-
fied workshop for repair.
You may sometimes have to release your vehicle's spring
brakes by hand. This could happen if the system air pres-
sure does not reach operating pressure because your
engine or compressor is not working properly. You will
have to release the spring brakes at the spring brake
chambers.
WARNING! Do not disassemble a spring brake
chamber. These chambers contain a powerful
spring that is compressed. Sudden release of
this spring can cause you to be severely
injured.
• Do not operate a vehicle when the spring
brakes have been manually released. Driv-
ing a vehicle after its spring brakes are
manually released is extremely dangerous.
You will probably have no brakes at all. You
could have a serious or fatal accident.
• Releasing the spring brakes on an unse-
cured vehicle could lead to an accident. The
vehicle could roll, causing severe injury.
Always secure the vehicle with wheel
chocks, chains, or other safe means to pre-
vent rolling before manually releasing the
spring brakes.