A fluid level sensor for determining an amount of first fluid in a system is provided including a first substantially transparent sight glass mounted outside and fluidly coupled to a portion of the system. A level of first fluid in the first sight glass is indicative of the amount of first fluid in the system. A second substantially transparent sight glass has an independent closed loop containing a second fluid. The second sight glass is positioned adjacent outside the system. A plane of the second sight glass is arranged adjacent to a pivot point of the first fluid within the system. A level of second fluid in the second sight glass is indicative of the amount of first fluid corresponding to normal operation of the system. A comparison of the level of first fluid in the first sight glass and the level of second fluid in the second sight glass indicates if the amount of first fluid in the system requires adjustment.