RE: Re: Wrecker Filter Question
First and foremost, let me say that I have no idea as to what the actual recommended fluid in this application is, just experience with hydraulic systems both new and old. Ten weight sounds like a likely choice given the vintage and the type of system, but I'd bet that there's ten or more fluids that would provide exemplary service in said tank, and dozens and dozens more that could actually cause or simply fail to prevent damage in the short or long term. You're right to question the use of the term, because it can be taken more than one way. One can't assume that hydraulic systems need fluid from a bucket labeled "hydraulic oil or "hydraulic fluid". Hydraulic describes how the system works, not the type of fluid. Hydraulic (oversimplified) means that the system is operated by non-compressable fluid in a confined space. 10 wt oil would be a hydraulic fluid if used in this application. 10w-30 is more commonly used now in simple systems that would have called for 10 weight. Brake fluid is a highly specialized and typically non-petrolium based hydraulic fluid, then there's automatic transmission fluid, power steering fluid... The water plant in town switches most of their valves at the plant with pressurized water, which once (and while) it's in the control circuits for the rams that run these big valves, it as well properly becomes a hydraulic fluid. Where the questioning of the term comes in is that you'll find many products that really have no other (signifigant) application that are called "hydraulic fluid". So, the first thing you must know is if the speaker (or writer) had in mind that "hydraulic fluid" would mean the product added to the resivoir or the job of the product added to the resivoir.