My dad has a 1998 Ford Expedition with a 4.6-liter Triton V-8 engine that produces 215 horsepower and 290 foot-pounds of torque. It's a nice truck, built on the extended-wheelbase version of Ford's "U" platform. He discovered, though, that all the horsepower and torque don't help one little bit when the engine overheated. It was time to replace the thermostat.
If the truck had been four-wheel drive, dad could have used the front crossmember as a jacking point, but since it is rear-wheel drive, he placed the floor jack under a bracket welded to the frame and put jack stands under the frame on each side. To get to the thermostat housing, dad had to remove the power steering reservoir support bracket. It was just a couple of bolts and the bracket came off, clearing the way to the thermostat housing.
On reassembly, he made sure the jiggle valve in the thermostat was installed at the 3 o'clock position, and he tightened the housing bolts to a range of 15 to 22 foot-pounds. To refill the system, dad used a good quality ethylene glycol-based coolant mixed in a 50 percent solution with water. According to Ford, he could have used any aluminum-compatible antifreeze.
