Air Injection: Service and Repair

AIR FLOW CONTROL VALVE, REPLACE

4-119 Engine

1. Disconnect hoses from valve.
2. Remove bolts securing valve to pump and the valve.
3. Reverse procedure to install.



4-119 Engine

1. Loosen pump mounting bolts and remove drive belt.
2. Disconnect hoses from air control valve.
3. Support engine with a suitable jack, remove engine mount retaining bolts and raise mount.
4. Remove pump mounting bolts and the pump. If pump is being replaced, transfer air control valve to new pump.
5. Reverse procedure to install.

Fig. 9 Air injection manifold. 4-119 engines:

4-119 Engine

1. Disconnect hoses from air manifold and remove components, as needed to gain access to manifold fittings.
2. Apply suitable penetrating oil to fittings securing air manifold to cylinder head, Fig. 9.
3. Loosen flare-type nuts securing air manifold to cylinder head, taking care not to twist manifold tubes.
4. Remove air manifold assembly.
5. Reverse procedure to install.

Fig. 10 Air pump filter fan removal. Except 4-119 engines:

CENTRIFUGAL PUMP FILTER

Removal

1. Remove drive belt, pulley bolts and pulley from air pump.
2. Using a suitable tool, Fig. 10, pry loose outer disc of filter fan. Carefully pry disc to ensure that no dirt fragments enter the air intake hole.



Installation

1. Install filter by drawing it on with the pulley, then evenly and alternately tightening the pulley bolts. Do not attempt to install a filter by hammering it or pressing the filter on.
2. Tighten pulley bolts until filter is properly seated. Ensure outer edge of filter slips into the air pump housing. A slight amount of interference with the air pump housing bore is normal.

CHECK VALVE, REPLACE

1. Disconnect air pump outlet hose from check valve.
2. Remove check valve from air manifold. When removing the check valve, do not bend or twist the air manifold.
3. Reverse procedure to install.

DECEL VALVE, REPLACE

1. Remove vacuum hose from valve, then 2 screws attaching valve to engine bracket.
2. Remove valve from bracket.
3. Reverse procedure to install.

DIVERTER VALVE, REPLACE

Pump Mounted Type

1. Disconnect air hoses and vacuum line from valve.
2. Remove bolts securing valve to pump or adapter, then the valve and gasket.
3. Reverse procedure to install, noting the following:
a. Use new gasket when installing valve.
b. Ensure that valve is properly seated, then torque retaining bolts to 60-70 lb in.

Remote Mounted Type

1. Disconnect air hoses and vacuum line from valve.
2. Remove bolts securing valve to bracket and the valve.
3. Reverse procedure to install.

MIXTURE CONTROL VALVE, REPLACE

1. Remove hoses from mixture control valve.
2. Remove valve attaching screws, then valve from clamp bracket.
3. Reverse procedure to install.