Milton CAT 772 User Manual
Page 13
Pistons. The Caterpillar two-piece piston
design combines the service, secondary,
parking brake and retarding functions in
the same system. The primary piston
hydraulically actuates both service
and retarding functions. The secondary
piston is spring-applied and held in
the disengaged position by hydraulic
pressure. If hydraulic system pressure
drops below a specified level, the
spring-applied secondary piston
automatically applies the brakes.
Parking Brake. The 772 parking brake
function is provided by the spring-applied
function in each of the rear oil-cooled
disc brakes. The 772 parking brake is
capable of holding the machine with a
rated load on grades up to 15 percent.
Automatic Retarder Control (ARC).
Standard ARC electronically controls
braking on grade to maintain engine at
approximately 2,200 rpm (adjustable from
1,950 to 2,200 rpm in increments of 10).
ARC is deactivated when the operator
applies the brakes or throttle.
• Faster Speeds. ARC allows the operator
to maintain optimum engine speeds for
up to 15 percent faster downhill hauls
and greater productivity.
• Superior Control. Automatic brake
modulation offers a smoother ride and
better control in slippery conditions,
allowing the operator to concentrate
on driving.
• Ease of Operation. ARC increases
operating ease, resulting in greater
operator confidence with less fatigue.
• Engine Overspeed Protection.
Automatically activates ARC when
engine speed exceeds factory preset
levels, regardless of operator inputs,
to avoid potentially damaging engine
overspeeds.
Traction Control System (TCS) (Optional).
Electronically monitors and controls rear
wheel slippage for greater traction and
enhanced truck performance in poor
underfoot conditions. If slippage exceeds
a set limit, the oil-cooled disc brakes
engage to slow the spinning wheel.
Torque is then automatically transferred
to the wheel with better traction.
Compression Brake (Optional). Optional
Compression Brake is integrated with
Automatic Retarder Control (ARC)
to provide up to 35 percent higher
downhill travel speed and reduce wear
on brake components.
10
Time (Seconds)
20
30
40
50
60
With Automatic Retarder Control
(average speed, 1,950 rpm)
With Manual Retarder Control
(average speed, 1,730 rpm)
Engine Speed (rpm)
70
0
2,500
1,500
1,000
500
2,000
13
1
2
4
3
5
8
6
6
7
7
TCS
ARC
1 Service Brake Sensor
2 Engine Sensor
3 ARC
4 ARC Switch
5 Brakes
6 Service Brakes
7 Axle Speed Sensor
8 TCS