Chevrolet 10 Series 1970 Service Manual page 390

EMISSION CONTROL SYSTEMS 6T-6
F ig . 10—C h e c k in g fo r Leaks
R e p la c e m e n t
• T o rep lace any hose and/or tube, note routing then
rem ove h ose(s) and/or tube(s) as requ ired,
CAUTIO N: The 1/4" pipe threads at the ex ­
haust m anifold (V8) a re a straight pipe thread.
Do not use a 1/4" tapered pipe tap. The hoses
o f the A .I.R . System a re a special m a teria l to
withstand high tem peratu re. No other type hose
should be substituted.
• Install new hose(s) and/or tube(s), routing them as
when rem oved.
• Tighten all connections.
NOTE: Use anti s e ize compound on threads of
the a ir m anifold to exhaust m anifold o r cylin der
head connections.
AIR SHOULD FLOW
IN THIS DIRECTION
ONLY______________
Fig. 11—A ir Flow Through C heck V a lv e
Fig. 12—Removing C heck V a lv e
CHECK VALVE
In s p e ctio n
• The check valve should be inspected whenever the
hose is disconnected from the check va lve or when­
e v e r check valve fa ilu re is suspected. (A pump that
had becom e inoperative and had shown indications
of having exhaust gases in the pump would indicate
check va lve fa ilu re ).
• O ra lly blow through the check va lve
m anifold) then attempt to suck back through check
va lve. Flow should only be in one direction (toward
the a ir m anifold) (fig . 11).
Replacement
• Disconnect pump outlet hose at check va lve. Rem ove
check va lve from a ir m anifold, being careful not to
bend or tw ist a ir m anifold (fig. 12).
F ig . 13—C h e ckin g fo r V acuum S ig n a l a t D iv e rte r V a lv e
(toward a ir
CHEVROLET TRUCK SERVICE MANUAL