HELP 300 loader on 790 quit... lift, bucket curl

[spruce Deere]

O.k discovered Loader works fine when 3 point is lifting... soon as the 3 point is done lifting, fel is done working bucket curl up, boom up.

 

[beenthere]

Don't miss the "re-setting the quick couplers" as that has been a problem before. Just disconnect and re-connect them.. sometimes they apparently do not seat.. Hope it is an easy fix as that.

 

[texasranger556]

O.k discovered Loader works fine when 3 point is lifting... soon as the 3 point is done lifting, fel is done working bucket curl up, boom up.

How long have you had the loader installed? That sounds like the loader was plumbed wrong.

 

[spruce Deere]

Found the issue or issues hopefully, There is two o-rings on the load relief. Deere part numbers ch10568 which is actually called 'packing' and ch14634 o-ring. Both were half gone. Getting the o-rings out of the relief was fine but getting the 'packing' o-ring back in correctly is being rather challenging. I might just cave and call the dealer......

The loader has been on the tractor since new and has always worked very well till now.

 

[spruce Deere]

Good news, upon taking off the "valve" that is also the 3 point cylinder head, out fell a threaded plug out of the valve.... Odd I thought till I looked straight into the valve from the 'out' port from the 3 point valve to the loader valve and could see threads in a port where this plug had come from. It must be some plug to divide the flow for other hyd. implements requiring another valve of some sort.

Even more odd is that the hex was 1/4 inch on a metric tractor, metric hexes were not a good fit at all. So I carefully put the plug back in, tightened it down back in the valve. After I installed the valve and the got hydraulic lines back on the loader came alive again.

Proof the parts diagrams do not always show items or how or where they belong. The o-ring locations were misleading come to find out also. Diagrams are very helpful, but be mindful of whats where on disassembly It will help greatly with re-assembly.

On a side note, I finally ordered a deere tech manual for the 790, a real number matching DEERE tech manual. Should have done it 10 years ago when I bought the tractor.....

 

[beenthere]

:thumbsup: :thumbsup:

 

[texasranger556]

I have seen that configuration before. I think it was a Massey Ferguson 1500 series. When you install the loader valve, a plug gets installed to divert the oil to the loader valve rather than allow it to all bypass to the 3 point. If you forget the plug, the symptoms match what you were describing.

Nice job finding the plug and getting it back in!

 

[spruce Deere]

Yep, something like a divert plug you would think would be in the valve parts diagram, its probably in the hyd. lines section or radiator section something elts