The system is designed to reduce the toxicity of exhaust gases

It functions in all engine operating modes, with the exception of idling and full throttle opening mode, and is also blocked when the engine temperature is below 40 ° C.

The system consists of a recirculation valve with a diaphragm, a thermal vacuum switch and two hoses.

Exhaust Gas Recirculation Schematic

The thermal vacuum switch valve is closed when the engine is cold.

The switch is connected by one hose to the carburetor over-throttle space, and when the engine is running, a vacuum is created in the hose.

Another hose goes to the switch from the recirculation valve.

When the engine warms up, the thermal vacuum switch valve opens and passes vacuum to the recirculation valve, opening it.

Part of the exhaust gases through the bypass hole is sucked into the intake manifold and burns out in the engine cylinders, which reduces the toxicity of the exhaust gases.

Removing the thermal vacuum switch and recirculation valve

Drain part of the liquid from the cooling system.

Exhaust gas recirculation ZMZ-402

Remove two hoses from the thermal vacuum switch.

Exhaust gas recirculation ZMZ-402

Using a "27" key (preferably a ring key), we unscrew the switch from the cylinder head.

Exhaust gas recirculation ZMZ-402

Remove the hose from the recirculation valve fitting and unscrew the two nuts with the “13” key

Exhaust gas recirculation ZMZ-402

Remove the recirculation valve from the exhaust manifold

Exhaust gas recirculation ZMZ-402

Use the "8" key to unscrew the three bolts

Exhaust gas recirculation ZMZ-402

Remove the valve from the body.

We assemble and install the valve and switch in the reverse order