Jergens Pre-Fill Boosters offer many more advantages than conventional boosters while maintaining the same basic simplicity. Our Pre-Fill Boosters have (2) automatic cycles. The first cycle pre-fills the work circuit using low pressure with a large reservoir to provide volume. The second cycle then automatically provides high pressure as needed. These units also provide automatic bleeding of the work circuit. This self-bleeding feature negates the need to “bleed the lines” after it is set up.