Hello all, Can some one explaine to me the function of the full load and part load breather...It seems clear the both relieve crankcase presure,but why is one a full and one part load, how do they Interact? where Is the relieved presure exhausted to?..how do they affect performance?..I just had my oil changed and they overfilled by half a Qt...should I suck out the overfill? shop says It fine to leave alone?? Thanks

 

The throttle plate is fully closed, or very nearly so, at idle and only open a small fraction at normal cruising range. Therefore, there is little vacuum on the filter side of the plate at part load. At that time the part load breather tube, connected on the engine side of the plate has a much higher vacuum and sucks crankcase gasses into the intake manifold.

At a more open throttle plate as under full load the vacuum is equalized and the gasses are sucked through the much larger breather tube.

In both cases the gasses are recycled into the cylinders and burned. That eliminates the blue smoking cars of yesteryear.

A half quart too much is not too much.