Need help on fuel line on old Deere 2020

aaluck

Active member

Equipment
L4400HST
Oct 9, 2019
214
73
28
Montgomery, AL
I know that this is a Kubota forum, but I guy I share hunting land with needs some help and cannot seem to find it anywhere else. I thought maybe someone here could help. Anyway, the tractor is a Deere 2020 made in around 1968.

He had a leak on his fuel line. The tip of the line was damaged through age not accident and fuel was leaking at the engine, not pump. When the fuel leak started the tractor would lose power and run rough. Prior to this he didn't have a single problem with the tractor. After he was finally able to secure a new line we began the process of putting the new line back on--with the help of the old farmer we lease the land from, who actually has one of these tractors as well (and several others) and is very familiar with this machine.

We put a very small washer on each side of the male banjo bolt where it contacts the female side (although he only remembers there being one on there when he took it apart--Deere guy told him he needed two--one on each side) and got it back in successfully. Now, where this line connects to the pump is nearly impossible to access, in fact we had to bend a wrench just to get to the banjo bolt head (see photos below).

Finished, started up like a champ and ran fine for a day. After that its hit or miss. Sometimes it will run fine, for a hour or so and then struggle with low RPMs and running rough. When it struggles if he loosens or tightens the bolt slightly (back and forth each time) seems to run fine for a while and then the same problem. Now, we were told that the "holes" of the banjo bolt do not need to line up as the fuel actually fills in a gap in between.

If anyone has any suggestions or ideas it would be appreciated.
 

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hagrid

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BX23S
Jun 11, 2018
115
12
18
Pittsburgh
The fitting is probably not tight enough to crush the sealing washers and you're sucking air.

Your buddy is correct about the banjo ports... they dont need to line up.
 
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D2Cat

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Mar 27, 2014
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Yes, the sealing washers would typically be copper. It looks like the bolt has something other then copper on it, like a neoprene flat washer, and maybe that is why the owner only remember one being on the banjo fitting.

Does the IP look like the one in this video? These pumps have a check valve in the line coming out of the IP for the return line going up to the injectors and to the fuel tank. They can get some material in there and it will allow the engine to run for short periods of time and then run out of fuel. Eventually it becomes plugged enough the engine won't stay running. Have to take the fitting off and clean the debris out.
 

aaluck

Active member

Equipment
L4400HST
Oct 9, 2019
214
73
28
Montgomery, AL
Yes, the sealing washers would typically be copper. It looks like the bolt has something other then copper on it, like a neoprene flat washer, and maybe that is why the owner only remember one being on the banjo fitting.

Does the IP look like the one in this video? These pumps have a check valve in the line coming out of the IP for the return line going up to the injectors and to the fuel tank. They can get some material in there and it will allow the engine to run for short periods of time and then run out of fuel. Eventually it becomes plugged enough the engine won't stay running. Have to take the fitting off and clean the debris out.
Which video?
 

D2Cat

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Sorry about that.

He shows the relief valve towards the beginning. It has a small glass ball about the size of a "BB" that needs to be free.
 
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aaluck

Active member

Equipment
L4400HST
Oct 9, 2019
214
73
28
Montgomery, AL
Does the IP look like the one in this video?
I'm going to check. Thanks for the info.

Do you think this would explain loosening and tightening the banjo bolt causing it to work for a while? Or, do you think that has to do with the washers?
 

D2Cat

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L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
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40 miles south of Kansas City
The banjo bolt should be installed, with the proper sealing washers, tightened and left alone. It should not need any thing. When the line is opened air is allowed to enter the fuel system and it causes fueling problems.

It seems like you have two issues. I'd suggest leaving the banjo bolt alone once properly in place.

You could remove the fuel return line at the IP and at the fuel tank. Put a rag over the end by the tank and blow some air through the line (5-10 PSI is plenty) to be sure the line is open. If the line is open I'd remove the 90 deg. fitting at the IP and get it clean, so you can see the glass ball, it rattles, and no filth in the fitting. Reinstall, and see what happens.
 

aaluck

Active member

Equipment
L4400HST
Oct 9, 2019
214
73
28
Montgomery, AL
The banjo bolt should be installed, with the proper sealing washers, tightened and left alone. It should not need any thing. When the line is opened air is allowed to enter the fuel system and it causes fueling problems.

It seems like you have two issues. I'd suggest leaving the banjo bolt alone once properly in place.

You could remove the fuel return line at the IP and at the fuel tank. Put a rag over the end by the tank and blow some air through the line (5-10 PSI is plenty) to be sure the line is open. If the line is open I'd remove the 90 deg. fitting at the IP and get it clean, so you can see the glass ball, it rattles, and no filth in the fitting. Reinstall, and see what happens.
Thank you very much. We will try this this weekend and report back.
 

D2Cat

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L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
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40 miles south of Kansas City
If you get to the fitting with the check valve, spray it with carb cleaner and blow on it, or pick some of the crud out and keep repeating until it's clean and the ball freely moves. Then reattach the fuel line at the tank and the IP, and see if it starts and runs.