Finally did a piston replacement on my B7100. Its sort of going again but I've noticed that fuel is leaking from the fuel pump connections to the injectors. It wasn't happening before the rebuild. Upon inspection it looks as if the O-rings on the connectors are broken or very hard and need replacing. Does anyone know what size they are in terms of inside diameter and thickness?
B7100 fuel pump outlet valve O-rings
- Thread starter Cryptohorse
- Start date
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
The O-ring are not your leak, the O-ring simply keep water and debris out of the delivery valve threads.
Yes replace them too, but what you need to fix the fuel issue is new delivery valve seals.
O-rings 15331-96760
Delivery gasket seals 15331-51240
Yes replace them too, but what you need to fix the fuel issue is new delivery valve seals.
O-rings 15331-96760
Delivery gasket seals 15331-51240
Thanks for the part number for the O-rings. I have already replaced the seals. Since they have to sit flush with the top of the delivery valve to make a good seal is there any procedure required to ensure that the seal gasket and its delivery valve are perfectly matched? I just replaced the seals thinking that they would just sit on top of the delivery valve and that would be enough to seal properly. That is the only reason i can think of which would create a leak. But strangely in all three injector lines at once?
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Could not find the torque for the delivery valve hosing in the workshop manual so I used the torque for injectors instead. 22 to 36 ft lbs. Think I used 30 ft lbs. Refer fuel system specs page 7-1. Do you have a better reference?
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
The torque spec is 4 to 4.5 kg-m or 29 to 32.5 ft/lbs.
Is the amount of fuel minor?
And are you sure it's not from the line fittings?
Replaced the O-rings and now there is no fuel leak from the delivery valve housings. But I think I have a problem with the governor as I can't easily start without setting the speed control lever to high speed. Once started it runs OK but won't idle very well. I recall having to undo the fuel limit apparatus assembly when taking out the adjacent banjo bolt holding the hydraulic pipe that runs under the fuel pump. Impossible to get at the banjo bolt otherwise.
I suppose the only solution is to undo everything and take the fuel pump out and try and adjust the fuel limit assembly. Or can it be adjusted externally by rotating the "nut" it slots into? Any suggestions on what to look for would be welcome.
I suppose the only solution is to undo everything and take the fuel pump out and try and adjust the fuel limit assembly. Or can it be adjusted externally by rotating the "nut" it slots into? Any suggestions on what to look for would be welcome.
Russell King
Well-known member
Lifetime Member
Equipment
L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Look at the Kubota illustrated parts list in Australia for a similar diagram as this.
looks adjustable from the exterior if this is what you’re referring to
looks adjustable from the exterior if this is what you’re referring to
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Did it work properly before your O-ring fix?
I've worked on quite a few B7100's, D650's, D750's, D850's, D950's and not a single one required messing with the idle adjustment.
There is a reason that that has a anti tamper cover over it.
If you set the throttle so that it moves the lever on the speed plate just the slightest it should idle no matter what the idle adjustment is set at.
If it won't then you have a either a fuel injection pump issue, which sounds very likely.
Or you have a spring issue, there are three springs on the throttle and governor.
Thanks for the advice and those drawings. Very helpful. I'm now able to use the tractor for moving hay bales around which was my major task. The guy who did my injector clean and repair said that they had a lot of junk/moisture in them and expected that the injector pump would be equally dirty. I get that tampering with the "tamper proof" adjustment screw was not a good idea but I seem to have gotten away with it for now. Its almost impossible to get a spanner on it without removing it. Not idling perfectly and has some issues instantly coping with increased load so I suspect I will need to get the fuel pump recalibrated at some stage.