What is the primary action involved in push loading with a crawler tractor?

The primary action involved in push loading with a crawler tractor focuses on centering the blade on the push block of the scraper. This action is crucial because it ensures that the tractor effectively and efficiently transfers material to the scraper. By centering the blade, the operator maximizes the amount of material that can be pushed onto the scraper while maintaining control and stability throughout the loading process. This is particularly important in achieving a balanced load, preventing spills, and enhancing the overall efficiency of material handling.

The other options, while related to operations that might occur around and with a crawler tractor, do not accurately capture the essence of push loading. For instance, pushing material downhill to a designated area describes a clearing or grading action rather than the specific mechanics of loading. Borrowing material from the edges of a site refers to excavating practices rather than the precise technique of loading material into a scraper. Similarly, loading material onto a transport vehicle pertains more to transportation operations than to the core action of push loading with a crawler tractor.