TB 1-1520-238-20-126
2. If required, use a soft brush to remove corrosion and evaporation residue.
NOTE
After corrosion has been removed, inspect inside of the valve for pitting,
paying special attention to the ball seats and check ball. If pitting exists
in either area, replace IAW paragraph 9a.
3. After the two way check valve has been cleaned of all corrosion, flush entire valve with
clean water and allow to air dry. Use of compressed air to expedite dry time is permitted.
(f) Inspect the three threaded portions on each valve using a 10X magnifier. If cracks are
noted, correct IAW paragraph 9a.
(g) Following the above inspection steps, if no pitting, corrosion, evaporation residue, or
cracking is noted, install valve IAW paragraph 9b.
(2) Inspect the Fire Bottle Outlet Ports at the next phase number 2 or 4, whichever occurs
next, as follows --
(a) Remove tube assemblies part number 7--311620503 and part number 7--311620504 IAW
paragraph 12.38, TM 1--1520--238--23 for the AH--64A, and the IETM for the AH--64D. Refer to figure
668, items 26 and 27, TM 1--1520--238--23P, for the AH--64A for the location of these tubes on the IETM
for the AH--64D.
(b) Inspect inside the fire bottle cartridge housing vertical outlet ports for evidence of pitting,
corrosion, or evaporation residue.
(c) If pitting or evaporation residue is found, correct IAW paragraph 9c.
(d) If no pitting or residue is noted, correct IAW paragraph 9d.
b. Recurring Inspections -- Clear the write--up for the recurring inspection on the DA Form 2408--18
required IAW AH--64--01--ASAM--06 (TB 1--1520--238--20--119). Enter a new write--up on the DA Form
2408--18 for the recurring inspections. These recurring inspections will be completed until the phase
maintenance inspection checklists have been updated. ULLS--A units will use this message as authority
to use their 800 inspection numbers for these inspections.
(1) Fire Extinguisher Check Valves -- At every phase inspection, complete the inspection for
corrosion of all three check valves as required IAW paragraph 8a(1).
(2) Fire Bottle Outlet Ports -- At each phase inspection numbers 2 and 4, complete the
inspection of the fire bottle outlet ports required IAW paragraph 8a(2).
9.
Correction Procedures.
a. If it has been determined the check valve or check valve ball is unserviceable IAW paragraph
8a(1) of this message --
(1) Dispose of the unserviceable component IAW paragraph 10d.
(2) Reinstall a new check valve IAW paragraph 9b.
b. Check valve reinstallation procedures --
(1) Apply Corrosion Prevention Compound (CPC), MIL--C--81309 Type II, to inside of two way
check valve.
(2) When the entire internal section of the valve has been coated, drain excess fluid from the
valve.
(3) Reinstall the check valve IAW TM 1--1520--238--23, paragraph 12.42 for the AH--64A and
the IETM for the AH--64D.
c.
If pitting or residue is noted on the outlet port --
(1) Clean with cotton swab dipped in corrosion removing fluid.
3