Harry in Ky
Member
- Location
- Central Kentucky
I guess this must another "old man's confusion moment" but here we are. I'm working on this 6640 12 X 12 open station tractor. Just installed two new hydraulic pumps today and I'm evaluating the results. The hydraulics are (as expected) greatly improved. Loader speed and operation are back to normal, it lifts the front end off the ground again, steering, PTO all doing fine.
Problem is this. I have a gauge hooked into the (deluxe) remote valve pressure line. Not in a coupler, but the pressure line itself between the priority valve pack and the remote valve. (Maybe that's a problem?) It's only reading a max pressure of 1700 PSI or so when the relief valve opens. Should be more like 2550 I believe. So I gave up for the day, come home, get the book out, and start studying, looking for possibilities for why would the pressure be that low. The tandem pump has it's own relief, (again supposed to be 2550 according to the book) new pump with new relief. I'm reading in the section on testing the engine mounted pump and it says to flow test through one of the remote couplers, and basically says it should produce like 6. something GPM at 2550 PSI. Says if this pressure is low overhaul priority valve pack before investigating further with the engine driven pump. Go back to the section on the priority valve pack and can find nothing concerning any relief valve in there. Looking at the parts breakdown I see nothing there either that's identified as any part of a relief valve. Has anyone ever been down down this road, and if so what was the end result? This is the only page I saw that covered the parts I think I'm looking at.
www.mycnhstore.com
Problem is this. I have a gauge hooked into the (deluxe) remote valve pressure line. Not in a coupler, but the pressure line itself between the priority valve pack and the remote valve. (Maybe that's a problem?) It's only reading a max pressure of 1700 PSI or so when the relief valve opens. Should be more like 2550 I believe. So I gave up for the day, come home, get the book out, and start studying, looking for possibilities for why would the pressure be that low. The tandem pump has it's own relief, (again supposed to be 2550 according to the book) new pump with new relief. I'm reading in the section on testing the engine mounted pump and it says to flow test through one of the remote couplers, and basically says it should produce like 6. something GPM at 2550 PSI. Says if this pressure is low overhaul priority valve pack before investigating further with the engine driven pump. Go back to the section on the priority valve pack and can find nothing concerning any relief valve in there. Looking at the parts breakdown I see nothing there either that's identified as any part of a relief valve. Has anyone ever been down down this road, and if so what was the end result? This is the only page I saw that covered the parts I think I'm looking at.
Valve, Hydraulic Lift Unload, L/ccls Pump | New Holland Agriculture | MyCNH US Store
Find schematics, manuals, specifications and diagrams for VALVE, HYDRAULIC LIFT UNLOAD, L/CCLS PUMP. Find genuine OEM parts for your needs.
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