jd 730 fuel problem

kurt v · Apr 1, 2019

new to me, if I bleed the fuel filters (new) the tractor will run (in my shop) for 20 min at 1000rpn no problem , shut it off in 15 sec it's like fuel is pushed back into tank through the check valve. I've taken the valve apart and the two washers (part no r 21727 r) were missing I have shimmed to about 60 thuo but still get blow by that seems to lose the prime, if tractor is restarted it will run out of fuel. Bleed the filters and will run good again. What is the thickness of the two shims that are supposed to be there? Or what can the problem be?
thanks
kurt

Mike M · Apr 1, 2019

I somehow do not think the check valve in the top of the pump cover would be the problem. I think this because I have a late 720 D that has the return fitting in there going to the tank and it does not have the check valve in it. Also this tractor if I shut off the fuel bowl shut off I still get fuel coming out back feeding from the return in the fitting above the fuel bowl.
I do not have any idea why yours does what it does short of a leak in the fuel filters or transfer pump ? Are you getting any fuel into your engine oil ? I have had a few that the injection pumps delivery valves leaked at their gasket.

kurt v · Apr 1, 2019

(reply to post at 12:44:23 04/01/19)

Mike, no fuel in oil, fuel pressure at no 1 bleeder is 20 psi ( should be between 12 & 24) I just don't know how much pressure the missing org washers are supposed to add to the spring. I can ad more shims but how much is the right amount?
thanks
kurt

kurt v · Apr 1, 2019

Mike I have taken the cover off of the pump , the piston is free BUT I don't know if the check ball Is free with out taking the pump off, don't want to do that if I can avoid it. Everything has been clean so don't think it is stuck.

thanks kurt

jd 730 fuel problem

kurt v

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Mike M

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kurt v

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kurt v

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