I think this is the right section for a TC-40.
Saw my brother today. We talked for awhile and then he asked me if I had ever bleed the fuel system on my TC-24.

Told me that he changed the fuel filter on his TC-40. Not sure if he tried to start it right then or tried to bleed the fuel system first.
The fuel gets all the way to the injector pump inlet. Only he cranked the tractor when he tried to bleed the system at the injector pump inlet. Then he opened one of the injector fittings at the engine, and never got any fuel to come out there.

Today I opened the banjo fitting at the inlet to the injector pump. (engine off). Waited for fuel to come out. (saw just a very little foam/bubbles). Then closed the banjo fitting with the fuel coming out. Then loosened one of the injectors. Brother cranked the tractor while I watched. Cranked for a total of about 30 seconds and nothing.

I guess the question is: Did we purge long enough to expect something? If purge was long enough, what should be the next thing to look at?

On our dodge (not sure of the JD) to prime the injectors it takes about 45 or more seconds for each injector.

My boss who have diesel tractor one time it run out diesel. It not his fault it was his friend who don't check diesel in tank. My boss just fill up it then spray starter fluid for 5 sec then try start again no then again starter fluid on those cap on hood then wait now it run. He don't have glow plugs.

And his 4 big tractor truck he just put diesel in fuel filter in it then close in box then it start with no problem. I think that how he do that so engine won't need crank long time to get diesel go in injector.

Well is his diesel become gel that why he replace fuel filter?

Do those have electric pump do you heard it run when put key in on position?

bubble come out hose sound strange to me.

http://www.messicks.com/Articles/TC-Service.aspx
Scan down till you get to
Bleeding the Fuel System
Bleeding the Injector Lines

and you should find your answers...:D

Thanks Paul, according to the information just keep cranking til fuel comes out.