When it gets hot it is likely to blow the fluid out the filler tube and push out any seals, than maybe a pump and other internal valves etc. Best thing is go buy a plastic fluid hand pumper and 8 ft of clear flex hose from the local parts place & slowly suck out a quart into a clean container.Measure it. That is easier than pulling the pan .
92 F150 XLT
93 Aerostar AWD
89 Bronco II