3 years is a bit to soon, but 5-7 years maximum is a good rule to follow. It is often neglected, as the transmission fluid, and rear axle fluid.
Seems they only advertize change your engine oil every 3,000 miles. Yet I also thing that 3,000 miles is to short for the engine oil. That is 33 changes in 100,000 miles. Letting it go to 5,000 miles means 20 changes per 100,000 miles, while 7,500 miles is going to work well with synthetic oil.
But for a hybrid car, I wonder how many miles you should go - as the engine will not be running all those miles, how do you know when you have 5,000 miles in, when the engine might be running only 1/2 of those miles.
Ford sells the highest boiling fluid DOT 3 brake fluid. Once the brake fluid absorbs moisture, such as a open can or installed in your brake lines, then the "Wet" boiling point is certified to be at least 375F on a basic brake fluid brand that will meet the minimum DOT standards. By using Ford brake fluid rated for use in the 24,000 GVWR F-53 chassis, your wet boiling point will be around 425F. And disk brakes can get that hot, then tiny droplets of steam can be formed in the hot disk brake calipers, and steam can be compressed, so that the hydraulic fluid will not transfer all of the brake pressure to the cylinder, until all the steam has been compressed back into water first.
Also check your flexible brake lines. Replace them by the time the vehicle is 15 or 18 years old. Any older, and the inside of the lines can break down, not holding the 2,000+ PSI brake fluid anymore, or worse just expanding when the brakes are applied, instead of transferring that pressure to the brake cylinder.
Fred.
