[Pitrede]

I have a 73 Ford 4000 with an aftermarket front loader. The control valve (single stick) is failing, does anyone have a recommendation for a replacement? Is rebuilding an option? Manual says hyd pump outputs 2500 psi at 5.4 gpm. I assume I need a valve with at least 5.4 gpm capacity but can go higher?

 

[Fedup]

You have a number of options. Replacement valves in eight to ten GPM rating are readily available from numerous sources should you need one. In most cases a valve of that type doesn't often "fail" to the point it needs replacement. What seems to be the problem with yours? I can see from your photo that the basic plumbing could use some improvements that might make it more convenient. Assuming it's currently supplied from a remote valve?

 

[HydroTek]

Looks like a "Cross" valve
what is failing about it ?

not much to fail besides an external leak or the linkage -- but those can be addressed

 

[Pitrede]

The problem is really slow response, almost nonexistent for the bucket after using it for awhile. It has plenty of fluid so that's not the problem. It might be the filter or fluid contamination. I ordered a filter and will replace that and the fluid and flush all the lines before I replace the valve. Any recommendations on doing that would be appreciated. The picture is old, I had all the cylinders rebuilt and replaced the hoses a year ago. It has worked perfectly until the last couple of weeks. Can I change the filter by removing the access cover on the left side or the pump on the right side or do I have to remove the lift cover? If I have to remove the lift cover, I might rebuild the lift cylinder. The plumbing looks weird because the loader is a quick change, I've cleaned it up some since the picture was taken. Thanks for the replies.

 

[Fedup]

Somehow I doubt the valve is the reason for your problem. If the cylinders have recently been gone through, more likely the flow from the pump is suspect. Is the problem with both circuits (lift and bucket) or just one? A pump supply /pressure problem will affect both equally. Does the three point still lift a load as fast as before with warm oil? If not, that also points toward the pump.

The plumbing doesn't "look weird", It's just that it only has two lines for supply and return to the tractor system. That could be done differently and the results could make operation more convenient. That's not part of your current problem, just an aside.

 

[Pitrede]

Thanks Fedup, not sure I've seen multiple supply and return line setup. My hyd adapter only two lines available, I guess I would need a different one if I changed the valve to a multiple supply/return

 

[Fedup]

Thanks Fedup, not sure I've seen multiple supply and return line setup. My hyd adapter only two lines available, I guess I would need a different one if I changed the valve to a multiple supply/return

What adapter are you using?

HV4902 VALVE PLATE KIT

VALVE PLATE KIT

agcrazy.com

Something like this?

 

[Fedup]

If that's what you have and it works for you, great. I prefer to use a power beyond configuration, rather than allow for pressure to build up on the return side. Your valve appears to be capable of power beyond, it would be a matter of locating the right sleeve and adding another hose.

There's nothing wrong with the two port adapter, but they usually have tapered pipe thread ports, which I don't care for. Also I need to find a separate sump return port somewhere on the tractor. Sometimes that's easy, sometimes not.

As for the actual problem. There really is no true filter on the three cylinder 4000. There is a suction screen on the hydraulic pump inlet. It's not exactly easy to get to, but if partially plugged it can certainly affect pump performance. If you're having hydraulic problems that affect both the loader and the three point, then I would be looking in that area before condemning the loader valve.

 

[HydroTek]

Remove the cover from the loader control and check to see that the spools are moving fully to the stops
linkage worn out may the the only problem here

Pictures of the linkage would help

 

[Busted Tractor]

Hydraulics are basically very simple. A pump takes oil from the reservoir and moves it to a control or work device, oil then return to the reservoir---- repeat.
When there is work to do the pump moves oil, the valve moves it in the direction to do work. Oil the forces the load to move.
Ok that is very basic
In a loader tractor the pump moves oil, the valve directs it to a cylinder to lift a load.
Things to remember:
A pump does NOT make pressure it only moves a specific amount oil oil. Usually referred to as Gallons Per Minute. Over time pumps wear and will have reduced flow due to wear causing internal leakage. Pumps are of two classes Positive displacement and variable displacement. Positive displacement usually an open center system MUST flow oil if something stops the flow something is going to break. Variable displacement usually closed center can vary amount of oil thru it. A pump cannot have full output if input flow is restricted.
A valve controls the output of the put it cannot reduce or increase the flow, unless there is damage either internal or external. The operator can "feather" the valve to control the speed the load operates. If the spool is not activated for the full travel speed of operation can be reduced, just as an operator feathering the valve.
A cylinder or motor causes work to be done it is the device that creates the pressure. Once the pressure rises enough to overcome the load movement begins
Things to consider.
1 a pump can appear to have a lot of flow with no pressure/load but may have no or little flow when under pressure. Also needs to have a unrestricted supply oil clean oil
2 a valve only controls the direction and amount of oil passing thru it. Unless it is damaged internally or leaks externally Isn't much can go wrong. Valve must be fully activated to get full flow thru the valve. If there is a control valve after the valve ie loader valve passing oil to a backhoe valve, the first valve needs a power beyond fitting and a separate return line.
3 When trouble shooting a valve especially a two spool valve try reversing the functions change lift to bucket, and bucket to lift. Does the problem remain the same or change to the "other" circuit?
4 A decrease in speed as unit heats up is usually but not always cause by pump internal leakage. As oil heats and gets less viscous and clearance increase due to heat
5 A true test of a hydraulic system requires pressure gauges and a flow meter.

Now with all that out of they way I would suggest doing the following-- of which some has been recommended
Be sure pump has a good supply of clean oil
Pull boot of control and be sure both spools a be fully activated.
No change --- Reverse couplers bucket to lift -- lift to bucket Does the problem follow the change?
Observe bucket and loader frame under load -- do they settle down when left for a period of time?
If using a front crankshaft driven pump is the drive slipping?
If using tractor hydraulic pump do all other functions slow down?

Yeah I know this is long winded but I hope it helps with your issues.

 

[Pitrede]

yes, it came with the tractor and I can't find any part numbers. It has only one pressure and one return. Is there something better you recommend?

Thanks for the troubleshooting plan, I'll try it and let you know what I find. I have a tractor pump in the side of the rear case.

 

[HydroTek]

You pulled that boot up and looked at the linkage yet ? post #9

 

[Pitrede]

Yes, linkage is fine, I'll swap the lines for the bucket and loader frame later today.

 

[Busted Tractor]

Yes, linkage is fine, I'll swap the lines for the bucket and loader frame later today.

Sometimes my forgetter works better than my rememberer.
While you had the boot off did you notice if both spools stick out the same distance and move about the same distance? Sometimes the centering spring on the end of the valve that is retained by a bolt loosens and prevents the spool from moving as far as it should.

 

[Fedup]

Somehow I still doubt your problem is in the valve. The key here is the three point. If that works, lifts a heavy load (not just the bare lift links) as fast as it should when the loader operation is failing, then the loader circuits are suspect. If the loader AND the lift struggle, that brings you back to a pump/supply problem.