TM 5-3805-262-20
3-7. COOLING SYSTEM TROUBLESHOOTING (CONT)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
3. COOLING SYSTEM NOT PRESSURIZED (Cont).
S t e p 1 . ( C o n t ) .
NOTE
I t m a y b e n e c e s s a r y t o r e i n-
s t a l l r a d i a t o r c a p s e v e r a l
times to ensure tight seal.
O p e r a t e p r e s s u r e t e s t e r
pump and watch meter
r e a d i n g a t i t s h i g h e st
point. Cap release pres-
sure should be 6-1/2 to
7-1/2 pounds, and should
remain steady for at least
30
a .
b.
seconds.
If radiator cap pressure is 6-1/2 to 7-1/2 pounds, and remains
steady for at least 30 seconds before dropping, go to step 2 be-
low.
If radiator cap pressure is not 6-1/2 to 7-1/2 pounds, or if
p r e s s u r e d r o p s r a p i d l y , r e p l a c e r a d i a t o r c a p.
Step 2.
Disconnect cap adapter from pressure tester.
A t t a c h p r e s s u r e t e s t e r t o r a d i a t o r f i l l e r n e c k , w i t h l o c k i n g e a r s in
line with entrance notches of filler neck,
Press down on tester and rotate clockwise until locking ears are
stopped by stop lugs on radiator filler neck.
Clamp radiator inlet and outlet hoses, or block hose flanges.
Operate pressure tester pump until meter indicates 10 pounds
sure, and watch meter.
a .
b.
c.
If pressure drops quickly, radiator has serious leakage.
r a d i a t o r ( p a g e 4 - 8 0 ).
If pressure drops slowly, radiator has seepage or slight
age. Replace radiator (page 4-80).
p r e s -
Replace
l e a k -
If pressure holds steady for two or more minutes, radiator check
is satisfactory. Remove pressure tester from radiator.
3-59
