See full version: Question: How To Bleed A Diesel Tractor
To purge air from the low-pressure side of the fuel system, open fuel – line unions and bleed ports downstream of the pump, one at a time, beginning with those closest to the pump, and continue pumping until fuel, and not air, runs out.
Where is the bleed screw on a diesel engine? There may be more than one, depending on the size of the motor. You can find them on top of the fuel filters fitted to the engine. Start by loosening the screw on the first filter by a half turn.
Well, what you should not do is try and start the engine without fuel, as injectors and other parts could be damaged due to lack of lubrication. As you know, diesel engines operate under extremely high fuel pressure. When fuel runs dry, air gets sucked into the system, and it must be vented (bled) out. more
Modern diesels are much more even tempered but can still require bleeding and you may well end up with a flat battery before it will fire up again. more
Re: Bleeding My Yanmar 3gm30f The only way to bleed the injectors is to loosen the nut at each high pressure connection at each injector. From personal experience, after rebuilding an engine it took 45 minutes of messing with the engine.
There is a bleed screw on top. Put a bag under it and open the screw and bleed fuel out of it. If you are replacing the fuel filter, pull the hose off it and run fuel into the new filter before you attach it. After bleeding it go to the injector bleed screw located just foward of the air filter.
When you change a diesel fuel filter, run out of fuel or disturb the fuel system, air is trapped. When you try to start the engine this air acts as a lock, preventing the normal supply of fuel into the cylinder. Here are the steps to take in bleeding air from a diesel fuel system: Turn off fuel valve.
The fuel system loses pressure with the truck off. Unless you have a cracked filter cap or bad line, the fuel system to the upper filter will purge when the truck gets turned on, and the fuel pump runs. You’d have a noticeable fuel leak. It’s probably a leak in your HPO system, or crack in your HPO reservoir.
How to Start a Diesel When it Runs Out of Fuel here
When you change a diesel fuel filter, run out of fuel or disturb the fuel system, air is trapped. When you try to start the engine this air acts as a lock, preventing the normal supply of fuel into the cylinder. Here are the steps to take in bleeding air from a diesel fuel system: Turn off fuel valve. here
Of all of the issues that cause a diesel engine not to start, this one seems to top the list. Remove your fuel filter and examine it. If it is dirty, it may be fully clogged, and not allowing fuel to get through to the engine.
A diesel engine is an internal combustion engine. That means that it creates a force by igniting fuel internally. The diesel fuel of a diesel engine actually lights on fire inside the engine to create the energy needed to propel your tractor.
Still, if you want to see what rebuilding one of these looks like, this YouTube video is very informative: here
Bleed the air out of the fuel filter with the bleeder on top of the canister or at the injection pump. This is just a gravity operation. When fuel shows up re-tighten the bolt. Next crack the fuel injection nuts on the fuel lines. Open them about 1/3 turn. Push the throttle to full and crank the engine. The fuel will not run steady, it will pulse. Crank for a bit and look for fuel instead of air. Then re-tighten the injector line nuts, start it and reduce the throttle setting. here
You said it would not "crank" This means it will not turn because of a dead battery or bad starter. I think you meant it would turn but not start. [links]
Be sure the fuel filter is full. On some diesels, it's pretty big and takes a very long time to fill up again. Then loosen the injector lines until you get a steady amout of fuel coming out of the lines without any bubbles. [links]
The spin, crack, & bleed method will work with a little time & patience. On your tractor, there is a more simple method. With the fuel flow established, unscrew the hand primer plunger and simply pump the primer until you feel it getting more firm (you may even hear fuel flowing back into the fuel tank through the return line). At this point push the primer back down one last time and screw it back in place. Should be ready to run. Hope this helps.
Scott @ Artec
Some guys pour fuel into the spin on filter before installing it, but that might not be the best way because of possible contamination. I've also seen guys pour in transmission fluid when they didn't have diesel available.