1020 scv issue

I have a early 1020 with the old style scv. When I use the one valve that tilts my loader it wants to keep feeding oil for a half second or so letting the bucket keep tilting. Since I know it does this sometimes, I can reverse the valve lever and bring it back and sometimes it just wants to keep tilting and then stopping. Seems like having a load on the loader makes it act up than without. Its been kind of hairy loading wood like this trying to keep the bucket level. I did put a new hydraulic pump on it last year and that was about when the problem began with having it's normal pressures again. This scv is also a float valve if that makes any difference. The bucket does drift very slowly now since this problem began and never did before. Is there an o ring blown or valve not seating in the scv? How hard are they to rebuild? My manual says about it taking a special plate/tool to adjust them. Thanks for your help!

More than likely one or more of the 4 poppet valves inside the housing is leaking. Those type poppet valves require special knowledge to get properly adjusted. I always thought JD engineers went out of their way to make the valves more complicated than necessary. A simple spool valve will control the frt end loader just fine.

Do the poppet valves just need adjusting , replacing, or new seals? I have instructions on how to set them and a tool # that is needed. I guess I would have to buy the tool from deere?

More than likely the beveled seating area on poppet valve is damaged requiring replacement & adjustment.

(quoted from post at 09:34:12 12/13/18) I have a early 1020 with the old style scv. When I use the one valve that tilts my loader it wants to keep feeding oil for a half second or so letting the bucket keep tilting. Since I know it does this sometimes, I can reverse the valve lever and bring it back and sometimes it just wants to keep tilting and then stopping. Seems like having a load on the loader makes it act up than without. Its been kind of hairy loading wood like this trying to keep the bucket level. I did put a new hydraulic pump on it last year and that was about when the problem began with having it's normal pressures again. This scv is also a float valve if that makes any difference. The bucket does drift very slowly now since this problem began and never did before. Is there an o ring blown or valve not seating in the scv? How hard are they to rebuild? My manual says about it taking a special plate/tool to adjust them. Thanks for your help!

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I am surprised with all the discussions here upgrading Dubuque/Mannheim hydraulic loader connections . That your tractor has not been upgraded to direct supply and ported transmission filter cover oil return .
We have also discussed how many times the front pump has been replaced instead of trouble shooting being done first . Usually the problem is transmission oil screen/filter, transmission oil pump, broken transmissio the oil lines , or blown pto clutch/brake seals .

I would pack up the valves and send to Tim S, he posts on here.

If you were on here last year this time you may have known what all I did to it. I went through EVERYTHING in the tractor last year. Flushed out all cylinders, remotes, power steering unit, etc. I put in a new transmission pump, hydraulic pump, and rebuilt the power steering pump from debris that went through the system. It all came from a brake that failed chewing 1/4 off the rear end housing. This all happened back in the early 70's as near as I can tell. The bottom of the rear housing was 1/4 thick of metal. Reservoir above hydraulic pump was polluted also. I also pulled the brake valve, and axles all apart. The tractor only gets about 20 hours a year mainly plowing snow and moving wood. No it probably wasn't worth it either. I even had the transmission apart because somebody lost the one thrust washer off the one shaft and made a homemade one to put on there. I knew the clutch was about shot too and replaced that while I was in there. It was my grandfather's tractor and I ain't getting rid of it. The hydraulics work way better now than I ever knew they could. I did all of this in about a week....MYSELF. I did ask for some advise from this forum also that helped also.

I have a 301a and power to my loader comes through the filter. Is that correct?

Hyd pressure to loader valve comes from rear of pressure control valve via hyd fitting(keys 13-16) Then after loader control valve oil is returned through ported hyd filter cover.