Volkswagen Air-Cooled 1970-1981 Repair Guide

Crankcase Ventilation System

Print

See Figures 1, 2, 3 and 4

Click image to see an enlarged view

Fig. Fig. 1: Crankcase ventilation system-1970-74 Type 1 and 2/1600 models



Click image to see an enlarged view

Fig. Fig. 2: Crankcase ventilation system-1972-74 Type 2/1700 and 2/1800 models



Click image to see an enlarged view

Fig. Fig. 3: Crankcase ventilation system-Type 3 and 4 models



Click image to see an enlarged view

Fig. Fig. 4: Emission control system-1975-81 Type 1 and 2 models

All models are equipped with a crankcase ventilation system. The purpose of the crankcase ventilation system is twofold. It keeps harmful vapors from escaping into the atmosphere and prevents the buildup of crankcase pressure. Prior to the 1960's, most cars employed a vented oil filler cap and road draft tube to dispose of crankcase vapor. The crankcase ventilation systems now in use are an improvement over the old method and, when functioning properly, will not reduce engine efficiency.

Type 1 and 2 carbureted engine crankcase vapors are recirculated from the oil breather through a rubber hose to the air cleaner. The vapors then join the air/fuel mixture and are burned in the engine. Fuel injected cars mix crankcase vapors into the air/fuel mixture to be burned in the combustion chambers. Fresh air is forced through the engine to evacuate vapors and recirculate them into the oil breather, intake air distributor, and then to be burned.

SERVICING



The only maintenance required on the crankcase ventilation system is a periodic check. At every tune-up, examine the hoses for clogging or deterioration. Clean or replace the hoses as required.

 
label.common.footer.alt.autozoneLogo