Hi, recently bought a '90 F250 7.3IDI and it has a small oil and fuel leak. Truck and engine has 145K. Oil leak is coming from rear of engine. Fuel leak is dripping from rubber fuel lines connecting injectors and pump and collecting in glow plug galley area. 1.) Any idea what might be leaking oil in rear of engine? It's only a few drips, not much, but I don't want it getting worse. Last owner just switched to synthetic oil and I am switching back to dino. 2.) A Ford dealer checked out the truck and reported something like the fuel return line is wet, but fixing this might cause the IP to leak??? 3.) I'd like to think I can replace rubber fuel line to fix part of the fuel leak, but I have heard that getting air into a diesel fuel system is bad and just don't know if I will get air into the system while replacing these, and if so, what to do??? Please help this new owner. Thank you!