Reassembly; Low-Buoy System (Coaches Only); Principles Of Operation; Maintenance - PREVOST H3-41 Maintenance Manual

SECTION 16 : SUSPENSION
FIGURE 42: AIR PRESSURE REGULATOR

10.3.4 Reassembly

1. Lubricate O-ring (14 and 16, Figure 42),
valve stem (13), tip of adjusting screw (1),
and the outer circumference and both sides
of the thrust washer (8) with a light coat of
good quality O-ring grease.
2. Assemble the regulator as shown in the
exploded view.
52 PA1621 Maintenance Manual All Series | Section revised October 2018
11 LOW-BUOY SYSTEM (COACHES
ONLY)
The purpose of the low-buoy system is to lower
the whole suspension by about 4" (100 mm) in
order to reduce the overall height for low
clearances. This system can be put into service
during normal vehicle operation.
11.1

PRINCIPLES OF OPERATION

The rear low-buoy is added over the front
kneeling system. The control valve on the left
console panel sends an electric signal from its
pressure switch to control the front suspension
as if kneeling. It also removes air from a relay
valve that exhausts air supply to all leveling
valves and the quick release in the rear section.
Air from the rear suspension can then be
depleted through the check valve-quick release
assembly.
DOWN:
The control valve, on the L.H. control panel, cuts
off air supply, so air is released from air springs.
A relay valve prevents height control valves from
supplying air springs.
UP:
The control valve, on the L.H. control panel,
supplies air to close the passage between both
the delivery and supply ports. A relay valve
opens and provides air springs until the
suspension reaches the normal ride height.
11.2

MAINTENANCE

Refer to the air system schematic diagram
"OPT. FRONT KNEELING WITH REAR LOW-
BUOY COMBINATION".
16035
12

AIR SYSTEM

The basic air system consists of an air
compressor,
interconnecting lines and hoses (refer to Section
12, "Brake and Air System" for complete
information). It provides a means for braking,
operating
suspension.
The air coming from the air dryer is first directed
to the wet air tank, then to the primary (for the
primary brake system), secondary (for the
secondary brake system), and accessory (for the
pneumatic accessories) air tanks (Figure 43).
tanks, valves,
controls and accessories,
filters and
and