Transmission having a vacuum ventilation control

摘要

A transmission includes a housing having the interior thereof connected for fluid communication with a vacuum source, such as an engine manifold. A check valve and regulator valve are disposed between the transmission housing and the vacuum source. The check valve prevents fluid flow from the vacuum source to the transmission while the regulator valve limits the maximum vacuum that can be drawn in the transmission housing. The normal transmission fill tube opening has installed therein a filter for restricting fluid flow to the interior of the housing or a cap for preventing fluid flow through the fill tube during normal operation.