1997 Mercury Grand Marquis Owner Guide 1st Printing - Page 223

If you must check the power steering fluid when it is cold, make sure that the fluid reaches the MIN mark on the reservoir. Automatic Transmission Fluid Under normal circumstances, you do not need to check the fluid level of the transmission, since your vehicle does not use up transmission fluid. Refer to the Maintenance Schedule booklet for replacement intervals. However, if the transmission is not working properly - for instance, the transmission may slip or shift slowly, or you may notice some sign of fluid leakage - the fluid level should be checked. Checking the Automatic Transmission Fluid It is preferable to check the transmission fluid level at normal operating temperature 150˚F-170˚F (66˚C-77˚C), after approximately 20 miles (30 km) of driving. However, if necessary, you can check the fluid level without having to drive 20 miles (30 km) to obtain a normal operating temperature if outside temperatures are above 50˚F (10˚C). With the vehicle on a level surface, start the engine and, while fully applying the brake pedal, move the transmission shift selector through all of the gear ranges allowing sufficient time for each position to engage. Securely latch the transmission shift selector in the P (Park) position, fully set the parking brake and leave the engine running. NOTE: Your vehicle should not be driven if the fluid level is below the bottom hole on the dipstick. 224