Chevrolet 10 Series 1968, Service Manual, Page: 421 / 713

AIR INJECTOR REACTOR SYSTEM 6T-2
EXHAUST TUBE
F ig . 2 - A ir Injection Pump
speeds the excess air is dumped through the pressure
relief valve which is part of the air pump.
The check valve(s) prevent exhaust gases from entering
and damaging the air injection pump, as back flow can
occur even under normal operating conditions.
When properly installed and maintained, the A.I.R.
System will effectively reduce exhaust emissions. How­
ever, if any A.I.R. component or any engine component
that operates in conjunction with the A.I.R. System should
malfunction, the exhaust emissions might be increased.
Because of the relationship between ’’Engine Tune Up”
and "Unburned Exhaust Gases", the condition of the En-
MAINTENANCE
DRIVE BELT
Inspection
• Inspect drive belt for wear, cracks or deterioration
and replace if required.
• Inspect belt tension and adjust if below 50 lbs. using
a strand tension gauge.
Adjustment
• Loosen pump mounting bolt and pump adjustment
bracket bolt.
• Move pump until belt is tight (55 ± 5 lb. used belt or
75 ± 5 lb. new belt using a strand tension gauge) then
tighten adjustment bracket bolt and mounting bolt.
C A U TIO N : Do not pry on the pump housing.
Distortion of the housing will result in extensive
damage to the Air Injection Pump.
Replacement
• Loosen pump mounting bolt and pump adjustment
VALVE IN OPEN POSITION
F ig . 3 -D ive rte r V a lv e (T yp ical)
gine Tune Up should be checked whenever the A.I.R.
System seems to be malfunctioning. Particular care
should be taken in checking items that affect fuel-air
ratio such as the crankcase ventilation system, the car­
buretor and the carburetor air cleaner.
Because of the similarity of many parts, typical illus­
trations and procedures are used except where specific
illustrations or procedures are necessary to clarify the
operation.
PROCEDURES
bracket bolt then swing pump until drive belt may be
removed.
• Install a new drive belt and adjust as outlined above.
DRIVE PULLEY
Replacement
• Remove drive belt as outlined above then replace
drive pulley.
• Install and adjust drive belt as outlined above.
PUMP PULLEY
Replacement
• Hold pump pulley from turning by compressing drive
belt then loosen pump pulley bolts.
• Remove drive belt as outlined above then remove
pump pulley.
• Install pump pulley with retaining bolts hand tight.
• Install and adjust drive belt as outlined above.
CHEVROLET TRUCK SERVICE MANUAL