Chevrolet 10 Series 1968, Service Manual

Page: 423 / 713

AIR INJECTOR REACTOR SYSTEM 6T-4
F ig . 7 -ln sta llin g Centrifugal Filter
• Check all tube and hose routing. Interference may
cause wear.
• If leak is suspected on the pressure side of the sys­
tem or any tubes and/or hoses have been discon­
nected on the pressure side, the connections should
be checked for leaks with a soapy water solution.
With the pump running, bubbles will form if a leak
exists.
Replacement
• To replace any hose and/or tube, note routing then
remove hose(s) and/or tube(s) as required.
CA U TIO N : The 1/4" pipe threads at the cylin­
der head (In Line) or exhaust manifold (V 8 ) are
a straight pipe thread. Do not use a 1/4" ta­
pered pipe tap. The hoses of the A.I.R. System
are a special material to withstand high tem­
perature. No other type hose should be substi­
tuted.
• Install new hose(s) and/or tube(s), routing them as
when removed.
• Tighten all connections.
NOTE:
Use anti seize compound on threads of
the air manifold to exhaust manifold or cylinder
head connections.
CHECK VALVE
Inspection
• The check valve should be inspected whenever the
hose is disconnected from the check valve or when­
ever check valve failure is suspected. (A pump that
had become inoperative and had shown indications
of having exhaust gases in the pump would indicate
check valve failure.)
• Orally blow through the check valve (toward air
manifold) then attempt to suck back through check
valve. Flow should only be in one direction (toward
the air manifold).
Replacement
• Disconnect pump outlet hose at check valve. Remove
check valve from air manifold, being careful not to
bend or twist air manifold.
DIVERTER VALVE
Inspection
• Check condition and routing of all lines especially
the signal line. All lines must be secure, without
crimps and not leaking.
• Disconnect signal line at valve. A vacuum signal
must be available with engine running.
• With engine stabilized at idle speed, no air should
be escaping through the muffler. Manually open and
quickly close the throttle, a momentary blast of air
should discharge through muffler for at least one
second.
• Defective valves should be replaced.
C A U TIO N :
Diverter valves although some­
times similar in appearance are designed to
meet
particular requirements of various en-
gines, therefore, be sure to install the correct
valve.
Replacem ent
• Disconnect vacuum signal line. Disconnect valve
exhaust hose(s).
• Remove diverter valve from pump. Remove muffler
from valve assembly noting angle of attachment.
• Install muffler to new valve at angle previously noted.
• Install diverter valve to pump or bracket with new
gasket. Torque valve attaching screws to 85 in. lbs.
• Install outlet and vacuum signal lines and check sys­
tem for leaks.
A IR IN JE C T IO N TUBE
Inspection (Fig. 5)
• There is no periodic service or inspection for the
air injection tubes, yet on In Line engines whenever
the cylinder head is removed or on V
8
engines when­
ever the exhaust manifolds are removed, inspect the
air injection tubes for carbon build up and warped or
burnt tubes.
• Remove any carbon build up with a wire brush.
• Warped or burnt tubes must be replaced.
Replacem ent
• On In Line engines remove carbon from tubes and
using penetrating oil, work tubes out of cylinder
head.
• On V 8 engines clamp exhaust manifold in a vise, re­
move carbon from tubes and using penetrating oil,
work tubes out of manifold.
• Install new tubes in cylinder head or manifold.
CHEVROLET TRUCK SERVICE MANUAL