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Discussion Starter · #1 ·
Worked on the B7100HST I bought a while back with a cracked block. Started to check it out today and try going with a good crack sealer. Drained the old fuel out as it has sat for 2 years. Filter cleaned and back on. Fresh fuel in and started the bleeding process. Opened the one bleed screw at the filter and got rid of the air. Went to the Injector Pump and could not get any fuel out the air bleed. Had the screw out about 3 turns and got a couple bubbles but no fuel. The operators manual talks about the filter bleed screw at the filter in the singular, but later I noticed there are two pointers pointing to two different screws. They are side by side but one is closer to the engine. Anyone had any experience with bleeding this system? It is my first diesel so have a lot to learn. Engine is D750A 3 cyl. Do I need to bleed both of the screws at the filter? What sequence if any?
 

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Does it have a manual pump on the side of the fuel pump or fuel filter housing? Pump it until you get fuel at the pump bleed screw. Then pump it some more until it starts getting hard. Heat the glowplug for 30 seconds and crank keep the throttle set just above and idle until it runs smooth.
 
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Does it have a manual pump on the side of the fuel pump or fuel filter housing? Pump it until you get fuel at the pump bleed screw. Then pump it some more until it starts getting hard. Heat the glowplug for 30 seconds and crank keep the throttle set just above and idle until it runs smooth.
Our old diesel air compressor had one of these pumps along the side of the fuel pump. Didn't look like a pump, all it had was a little lever that moved up and down. Got real familiar with the bleed procedure on that machine. Had it serviced at place of purchase. The pump actually had a little screen on the bottom. Well, they had cleaned this screen and reassembled the pump. The gasket didn't seal. No fuel leaked out, but air would leak in. Machine would run for about an hour; then needed to be bled. Took a few days to figure out what was going on.
 

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Does it have a manual pump on the side of the fuel pump or fuel filter housing? Pump it until you get fuel at the pump bleed screw. Then pump it some more until it starts getting hard. Heat the glowplug for 30 seconds and crank keep the throttle set just above and idle until it runs smooth.
I was wondering about that pump too. A lot of times it just looks like a plastic cap and you unscrew it a 1/4 turn and it springs up as a plunger pump. If you can't get fuel to the bleeder, then you need to go backwards and find the problem. Sometimes putting a clear hose at different places in the system you can see a leak by the bubbles.
 

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I wonder if you loosened one of the lines going to the injector, crank the engine over and see if any air or fuel comes out. I have only worked on one diesel tractor, so I don't know any thing. Just a thought, just like an oil furnace if it runs out of oil, have to get air out, and have fuel coming out so it will fire. I am sure you already know this. Hope fully it gets going and works for you.

Noel
 
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Discussion Starter · #7 ·
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Discussion Starter · #8 ·
Does it have a manual pump on the side of the fuel pump or fuel filter housing? Pump it until you get fuel at the pump bleed screw. Then pump it some more until it starts getting hard. Heat the glowplug for 30 seconds and crank keep the throttle set just above and idle until it runs smooth.
I could not find anything that looked like a pump lever. Many, many years ago i ran JD dozer out of fuel and had to bleed it out. Real pain with dual filters, etc. Owners manual says to crank the engine over to pump fuel.
 

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Will start at the fuel filter again and bleed both of the screws the manual points to. Then move to the injector pump and on to the injectors.
The glow plugs have power to them but haven't pulled them to check if they are actually working. Since it was used as a mowing unit I doubt if they were really used much if at all. Know they weren't in the last 2 years. I better check them too.

As I mentioned I bought this tractor and the PO siad it had a crack in the block. I drained antifreeze out the oil drain before oil came out. Plan is to try and stop that leak with some good quality stop leak. Left the drain plug out and filled the radiator with antifreeze. Let it sit for about 3 hours. Nothing coming out the oil drain and the level held in the radiator. GOOD SIGN. Filled it with fresh oil and now want to get it running for a while to give the crack sealer some time to work. With a lot of luck and persistence I just might save this engine and have a good tractor.
 
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Did you put a new filter in it?Did you Fill the filter with fresh diesel before you installed it?

My uncle had problems after replacing the fuel filter on his Ford 5000 loader tractor this past Thanksgiving.Could not get it to prime the pump.We went down there for Turkey and afterwards I went back to the garage to give him a hand.

He said it ran ok before he pulled the filters.I got to thinking and pulled the filters.It had maybe a couple tablespoons of fuel in it.I filled them and left them soak for a good hour then reinstalled them full of fuel.Yep I had Diesel all over the place.Down my arms,down front of my pants,on the floor you name it.

Fuel would come out of the line from the tank but would not fill the filters without being primed.

After I got cleaned up a bit we gave it a crank and it immediately had fuel at the injectors.We cranked her over a couple more times and she fired and we bled the lines.

Uncle went ahead and cut the filters apart and found them both caked with dirt and rust.He said he's going to be pulling the tank off and having it steam cleaned? and lined by a local radiator repair shop.
 

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Discussion Starter · #11 ·
I did not replace the filter as it had been done mid summer before it was put away. Dropped the cup off to check for water, dirt, etc. Was clean as could be. I did not fill it with fuel before I put it back on. Tank was clean as well when I drained it. Air filter was new also so had been serviced very recently prior to end of its last season. I have fuel at the top of the filter at the left bleeder. That could coming directly from the line too as have no idea how the internal configuration is on that set up.

With all the good advise I think it best if I go back and start over. Drain the tank (about a gallon), put on a new fuel hose, fill the filter and go from there. Want to check the glow plugs too. Should be able to feel if they are getting warm as cold as it is out (4°). Thanks for all the advise. Like I said, I have a lot to learn about this tractor. Having the right owners manual would help some also as the one I have is for the standard transmission and mentions several things that are not present on this tractor, or visa versa.
 
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Tinker Master
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Start @ the tank and work your way to the injectors.. You will need to crank the engine to make the injector pump work.. Take it easy on the starter while you do it.. Look HERE
 

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Discussion Starter · #13 ·
Start @ the tank and work your way to the injectors.. You will need to crank the engine to make the injector pump work.. Take it easy on the starter while you do it.. Look HERE
Thanks, just what I have in mind. Only put about a gallon of fuel in the tank so will fill it - after a new line is installed. Hopefully will have something poistive to report later this evening. Heading after parts now.
 
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Discussion Starter · #14 ·
One item that was not fully covered in the bleeding operation is the position of the throttle control during the bleeding. To stop the engine it says to pull back on the throttle and hold till the engine stops. When released does it return to an idle position? Or does the throttle have to be opened to allow the fuel to pass through the injector pump? Looks like when the throttle is pulled back it shuts off the fuel flow to the pump so the throttle would have to be opened some to allow the fuel to pass?
 

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Maybe I missed it but no one has mentioned that some of these engines require an electric lift pump. If your engine does not have a manual one than an electric should be used if your tank is lower than the injector pump. Even if the tank is higher I would install one to speed up the air purging process.

I was able to purchase a Kubota excavator for scrap price because the electric lift pump wasn't working.
 

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Discussion Starter · #17 ·
The way this one is set up the bottom of the fuel tank is higher than the injector pump. Will sure keep that in mind.
 

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Actually this excavator is set up that way also. It would take forever to get the air out of the system and then it would run. With the electric pump it only took a couple of minutes and it was running.

Another thing is make sure that the return line runs all the way back to the top of the fuel tank and is not teed into the fuel line. I had one set up this way and never could get all the air out of it. Finally got it started and just let it lope until it worked the rest of the air out on it's own.
 

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Most all smaller farm tractors have fuel tanks higher than the injector pump, but still use a mechanical fuel pump. Injection pumps make awesome pressure, but lack the ability to pull fuel. They need a little pressure to function properly. As Chris said, electric is the way to go. Makes the process SO much easier and faster.
 

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Discussion Starter · #20 ·
First this morning I checked the glow plugs. Removed each one and checked with 12V and ground. All OK. Went back to the filter and bleed the lines and filter with both screws. Fuel ran very free from both bleed screws. Went to the air release at the injector pump. Same results there, free flowing fuel. Opened the lines at the injectors and turned the engine over till I had fuel spurting out around the nut with no air bubbles. Tried to start it and would not go.
Went back and bleed everything again. Still would not run and no white smoke from the exhaust. Tomorrow morning I am going to remove the injectors and clean them as I have a feeling that they are restricted and not spraying fuel into the cylinder. Anyone see anything I may have missed?
 
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