FARMALL 656 HYDRAULICS which pump does what?

I have a 656 which the 3pt will not lift over 500 lbs. I rebuilt the control valve,replaced o-ring on piston,relief valve is ok. Still no lift.
I have read on here that the rear pump feeds the 3pt and the front pump feeds remotes and steering.A mechanic at the local IH dealer tells me front pump feeds 3pt and remotes and rear pump feeds steering and lubrication.I am lost who is right?

a 656 does not have a front and back pump it has a piggyback pump on the big pump that only supplys the steering the big pump feeds your 3 point and remotes

If your remotes work ok then it is not your pump if in doubt just take a pressure gauge for at least 2000 psi and plug in a coupler on the remotes and pull lever it should go to around 1500 or a little more you will have to run the engine at rated pto speed or nearly that to get the psi reading to even be close to the 1500 or more. The pressure could be more than that. My 806 will only go to about 1500-1800 psi but there are a lot of things to affect that worn valves and springs in them.

656 is a small frame tractor.

Therefore, the front pump handles everything EXCEPT the hitch; it supplies oil for steering, remotes and lube. Rear (piggyback) pump handles the hitch only under normal operation. That's why it is called the hitch pump. :>)

However, under full system demand, and IF the hitch isn't being used (or has arrived at the end of the hitch piston's travel), the rear pump can/will assist the front pump in it's duties.

But, not the other way around.

So, if yer hitch isn't working right, (everything else is okay) suspect the rear pump. Especially so, since we're talking a tractor that old.

Allan

Your 806 uses a totally different system. That is a large frame tractor.

Allan

I know everybody means well, but i'm still getting different answers. I have already bought a new front pump that didn't help me. I want to be sure before i buy another pump. I went from a 12 to a 17 gpm pump and it made no difference in the 3pt,but there was a big difference in the way the steering and remotes reacted,remotes went from being good to extremely fast.
I thank you all but i still need help.
Which pump does what?

Pretty much what Allen said but if your looking for something formal the following is straight from the [color=blue:a0c8b146d0]IH Blue Ribbon Service Manual #GSS-1383 Chassis 656 Series Tractor....[/color:a0c8b146d0]

[size=18:a0c8b146d0]HYDRAULIC AND LUBRICATION SYSTEM[/size:a0c8b146d0]

There are two pumps located in the clutch housing and one in the IPTO housing. All use a common fluid supply which furnishes fluid and lubrication for the power steering, transmission and final drive, IPTO and the auxiliary valves.

[size=18:a0c8b146d0]Power Steering and Auxiliary Valve Supply[/size:a0c8b146d0]

The pump output, regulated at 1,600 psi goes to the flow-divider and 3.5 gpm at priority is diverted to the power steering valve. When power steering is not in use this flow goes through the valve to the cooler and from the cooler to the tee located in the left side of the clutch housing. A small amount goes down into the clutch housing through an orifice. This orifice dumps below fluid level at all times and is for the sole purpose of supplying make-up fluid during manual steering.

The balance goes to the lower port on the load control junction block and lubricates the differential and bull pinion bearings. There is a check valve in this block for the purpose of closing off the suction during manual steering.

During power steering the flow goes to one side of the cylinder and the return fluid out of the other side of the cylinder goes back through the power steering valve and follows the route described above.

There is an oil cooler by-pass relief valve (90 psi) in the right side of the clutch housing which goes back to dump. This valve is to by-pass the cooler for a quick warm-up of fluid and to provide relief if the cooler becomes restricted. The remaining flow from this pump goes to the junction block on the right hand side of the load control. When no demand is present, this flow goes through the open center valves to the suction pipe in the frame sump. When the auxiliary valves are placed on demand, the flow goes through the open center valve to the cylinder in use.

[size=18:a0c8b146d0]Hitch and Supplemental Auxiliary Valve Supply[/size:a0c8b146d0]

The hitch pump flow goes back to the top port on the junction block on the load control and to the load control valve. When neither the hitch nor the auxilary valves are on demand, the fluid goes [color=red:a0c8b146d0]through[/color:a0c8b146d0] the check valve in the junction block through the open center valves back to the suction line to the sump.

When the hitch alone is activated to raise, the flow goes through the control valve to the cylinder. When the hitch is activated to lower, the fluid from the pump goes as described above.

The fluid from the cylinder goes through the action control valve to the load control housing, the overflow pipe returns it to the sump. This flow going to the hitch is available for the auxiliary valves if not required for the hitch.

When the hitch and the auxiliary valves are placed on demand the hitch will move independently of demand of auxiliary valve system. This means that the flow from both pumps would be available for the auxiliary valves after the hitch demand is satisfied. The flow for the auxiliary valves is not available to the hitch because of a check valve in the junction block.

Auxiliary pump 1550-1600 psi
Hitch pump - 1950-2000 psi
Hitch relief valve opening pressure 1700-2000 psi

End quote, begin comment...

I think a new piggy back pump is getting close to $500? You can get a wear plate kit and gaskets from CIH for about $83. I don't have any 3 point implements of that size so I don't know how effective the $83 kit was. I just did it because I had opened up the piggy back pump while putting in a new 17 GPM main pump. Don't forget to order the miscellaneous o-rings and pump body gasket if you go this route. Not all of them are in the kit.

Thanks for all the help. I"ll order a new piggyback pump tomorrow. Seems that TX656 and Allen know there stuff.