i have a 743 that runs good, but for awhile now it has been bogging down alot on us. Its always been hard to start when it is cold outside, i hear a clicking sound when i hit the glow plugs, but i don't know if they work or not. Once it starts, fires right up ever time all day, just sounds like its straining. Trying to work and it will bog down, drive to quickly, say, up a small incline, it will bog down, and esp. when i load the truck and try to lower the arms and curl back the bucket at the same time it almost will stall. we have changed the fuel filter, removed and cleaned the fuel tank and line filter, keep the air filter clean, but it still bogs down. someone told us the injector pump may be wearing out, but im not a mechanic. Could a hydro filter cause it to bog down? I'm stumped.