The 155TS2’s valve assembly functions on a dual cartridge system, using a Sequence and Counter Balance Valve. When engaged, this allows the Apron to open fully prior to the Pushoff moving forward to eject material. Once the ejector wall (Pushoff) has thrust the payload forward, the operator can reverse the control lever in the cab, allowing the ejector wall to retract while the Apron remains open. This system gives the operator the ability to begin loading the scraper immediately. Once the ejector wall is fully retracted to the rear of the Bowl, the sequencing cartridge will divert oil to the Apron — at that point, the Apron will close fully.
If you’d prefer to control your scraper’s Apron independently from the ejector, there is a three circuit option for greater control.