Page Issue 01
Chapter - Pneumatic System
11:4
VT551 - Maintenance
AIR FILTRATION AND REGULATOR (FR)
A filter regulator unit, located near the fan case in the right hand side of the body, filters the air for the
sweeper section of the pneumatic system to prolong the life of the components served by it.
Before carrying out any major work on the unit, other than that described in the Routine Maintenance
Section of the Operator’s Guide, it will be necessary to remove it by first draining the vehicle air system,
then disconnecting the supply pipes and releasing the fixing bolts.
PNEUMATIC VALVE ISLAND
The pneumatic valve island is a modular unit comprising various valve segments. Each valve segment
has an indicator light that illuminates when energised (A) and a manual override button (B) for ports 2 or
4 on each segment
The segments are identified by a code and are not all the same - see following tables.
B
3
0
0
N
B
6
U
N
G
6
U
N
B
6
U
N
A
6
U
N
G
6
U
N
B
6
U
N
A
6
U
N
A
6
U
N
G
6
U
N
G
6
U
N
G
6
U
V21
23
V22
24
(H)
(G)
(F)
93MA. 004
VALVE
NUMBERS
OVERRIDE BUTTONS FOR
VALVES V2 - V24
OVERRIDE BUTTONS FOR
VALVES V1 - V23
DUAL SWEEP VALVE
WITH OPTIONS SHOWN
VALVE
NUMBERS
SEGMENT
CODES
(C)
(E)
(A)
(D)
(B)
(B)
12
- LAMPS FOR VALVES V2 - V24
14
- LAMPS FOR VALVES V1 - V23
V2 4 6 8 10 12 14 16 18 20
V1 3 5 7 9 11 13 15 17 19
To replace a valve segment -
1) Remove the 4 fixing screws (C).
2) Remove the 4 socket head screws (D).
3) Remove the valve cover containing the valve operating coils (E).
4) Unscrew (F) each side of the segment to be replaced.
5) Fold open the segment (G) and replace ensuring the rubber gasket (H) is in position.
6) Tighten screws (F).
7) Replace top cover (E).
8) Replace screws (D).
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and rights are the property of Johnston Sweepers
Ltd
