The reservoir is a necessary component when fitting vacuum brakes. The reserve of vacuum (if there is such a thing) makes it possible to create the differential between it and atmospheric pressure to apply a force on the diaphragm, thus applying the brakes.

The vacuum reservoir comes in kit form.

The kit includes two prototypical-moulded ends, a length of plastic tubing and a sturdy purpose made strap and mounting clip.

To assemble simply insert the moulded ends and glue with a suitable adhesive such as araldite.