Engine maintenance

[dzimbric]

My '08 LMM just passed 300K and I wondered what other maintenance it needs. I just replaced the upper and lower ball joints, front wheel bearings, sway bar bushings, u-joints, shocks, front brake calipers and had the t-case and tranny serviced. What else should I do?
Mods 4 inch lift, cold air kit, DPF delete, 4 inch exhaust and tune from Diesel Domination. Mileage after the tune and mods was as high as 22 if I ran 70 on the interstate but seems to have dropped in the last year. Is there any specific engine maintenance that I should do or may cause mpg reduction? It has the original stock injectors.

 

[Ron Nielson]

Complete change of your brake fluid and power steering fluid. Diff fluid, trans fluid, coolant changeout.

 

[dzimbric]

Yeah, I did the brake thing when that pesky white tail ran out in front of me last year. Stomped the brake hard enough to lock the ABS and blow a brake line. It got new a new master cylinder and brake lines after that incident. Also replaced all of the fuel lines and e-brake cables. I bough the truck new in '08 but lived in the Michigan for a couple years. Fuel lines and brake cables got corrrded and had to be replaced after I moved to a warmer climate, Never the touched the coolant, I'll add that the list. Tranny, t-case and pumpkins get serviced per factory recommendations. I'm really looking to restore my fuel mileage to where it used to be.