TB
5-4220-200-12-1
Table 4-3. TROUBLESHOOTING - UNIT (CONT)
A. AIR DEMAND REGULATOR TROUBLESHOOTING INSTRUCTIONS (CONT)
ITEM
CORRECTIVE ACTION
NO.
MALFUNCTION
PROBABLE CAUSE
2
a. Lever (fig. 4-2) (18) out of ad-
Weak purge flow.
a. Readjust lever (18). Section V.
justment.
b. Lever (fig. 4-2) (18) bent.
b. Replace lever (18). (Section V.
a. Readjust lever (18). (Section V,
3
Hard to breath.
a. Lever (fig. 4-2) (18) out of ad-
justment.
b. First stage regulator intermediate
b. Readjust the first stage
regulator adjusting screw (27).
pressure set too low (fig. 4-1).
(Section V, para 4-13c).
c. First stage regulator filter (fig.
c. Clean or replace first stage
regulator filter (8). (Section Ill.
4
Hissing sound from
a. Lever (fig. 4-2) (18) out of adjust-
a. Readjust lever (18). (Section V.
the second stage
ment.
regulator.
b. First stage regulator intermediate
b. Readjust first stage regulator
pressure set too high (fig. 4-1).
adjusting screw (27).
(Section V, para 4-13c).
c. Disc and Retainer (fig. 4-1), (14)
c. Clean or replace (Section Ill,
and (15) first stage regulator dirty,
damaged or worn.
d. Inlet fitting (fig. 4-2) (12) dirty,
d. Clean or replace (Section Ill.
damaged or worn.
para 4-7 or Section V,
e. Second stage regulator hose as-
e. Remove and replace
sembly O-Ring (fig. 4-2) (28) .
(Section V, para 4-14b).
damaged.
f. Second stage regulator inlet fitting
f. Remove and replace
O-Ring (fig. 4-2) (13) damaged.
(Section V, para 4-14b).
5
High pressure leak
a. First stage regulator disc and re-
a. Clean or replace (Section III.
from the first stage
tainer (fig. 4-l) (14) dirty. damaged.
regulator.
or worn.
b. Verdigris build up on the first stage
b. Clean or replace. (Section III,
regulator disc and retainer (fig. 4-1)
(14) and the regulator body interior
walls (fig. 4-1) (15).
4-4
