2011 F250 diesels have vacuum assist brakes-I have one. They have a vacuum pump driven by the engine to create the necessary vacuum for the brake system and 4x4 axle. Most if not all diesels have a vacuum pump as something on the truck is vacuum powered. It is a change that Ford made for 2011-F250 diesels have vacuum brakes. Previous to 2011, diesels got hydro and gassers got vacuum.
As for the rear spring pack, Ford made another change there as well. The F250 got the 3-leaf pack to make the unloaded ride better. If the 250 has the camper package, they have the same springs as the 350.
Don't know why they made these changes. The springs I can see for ride quality. Brake system-who knows. I don't feel any difference in the brake assist or stopping power with mine vs. a 350 with hydro-boost. Drove both, got the 250 because the 350 won't fit in the garage.
Dave and Amy
5 kids...2 with 2 legs, 3 with 4 legs
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