Cash in the account feels like freedom until the job site drains it. A lot of operators who could finance a truck instead write a check for it, then spend the next eight months scrambling for fuel money, payroll, and the next set of tires. The truck is paid off but the business is cash-poor, and cash-poor businesses lose bids they should win.
Equipment financing and working capital are not competing products. They solve different problems, and mixing them up is one of the more expensive mistakes in this industry. This page lays out when each one belongs in the deal and how to think about the trade-off on a water truck purchase specifically.

