I have a 720 diesel with an electric start. The tractor will start easy for 5 or 6 times , and then all of a sudden , it will not start. I found that if I bleed the last bleed plug on the left side of block, I get air bubbles. After getting all the air out, it will start easy again for another 4 o 5 times .
Can someone give me a idea where the air might be getting into the line?