Loader Valve / Curl function diagnosis

[GPintheMitten]

Yah, I plan on tearing into for curiosity sake. In theory, you can replace the spools but they are such close tolerances, my concern is that the casting could be scratched or cracked.

 

[J_J]

The problem with your valve is almost inconceivable.

The grooves in the spool are cut to allow a flow path from the pump side through the valve in neutral.

When you move the lever, you are moving the spool to match with another port.

In the no regen position, the flow from the pump goes into the spool groove and to one of the work ports, and opens another grove for the cyl fluid to escape.

Even if the port was blocked, the flow would pass over the relief valve.

So, since the problem started, you have not seen any flow from the one work port.

It could be that a piece of the valve has broken off inside the valve.

When you remove the spool, and if it is complete, then the problem is internal and you might never see why.things are not working correctly.

Are you also saying that after you dumped the bucket, it never curl back up, or you curled up and it never did dump after that.?

 

[Leejohn]

I don't see a relief valve. Is there one before the valve on the tractor?

 

[GPintheMitten]

I curl it up but can not dump. Sometimes I notice that it has gradually dropped (dumped) a small amount. I can curl it back up but I can not dump it.

This condition started after I accidentally abused it. I had the bucket dumped and was grading forward in the evening when it was getting dark and hit a farm gate at the hinge side where it is bolted to a cemented in 6x6.

At the time, the dump function slowed and eventually stopped altogether.

So while it may be unusual, the system did take a big hit

And to answer your other question, since it failed I believe there is no flow at all to the dump function. That is, I can not dump the bucket.

 

[GPintheMitten]

I don't see a relief valve. Is there one before the valve on the tractor?

I'm told that there is a relief valve internal in the control valve.

 

[LD1]

That shock load might have cracked an internal casting. Although I would thin there should still be enough flow to allow gravity to dump the bucket.

 

[J_J]

I'm told that there is a relief valve internal in the control valve.

Yes, there is a relief valve in the valve.

Item #60 in the parts manual.

It uses shims to adjust the pressure.

It is under a hex plug on the valve.

 

[J_J]

It is maybe to late now, but you could have coupled in a new valve in place of the old valve using compression fittings. Cut off the banjo fittings and use compression fittings

New valve from Surplus would be about $250.

 

[Leejohn]

I don't recall anyone telling you to check the load checks in the curl and dump. It might got broken up and got pushed into the galley of the dump.

 

[GPintheMitten]

I don't recall anyone telling you to check the load checks in the curl and dump. It might got broken up and got pushed into the galley of the dump.

When I took the valve into the hydraulic shop, he looked at both poppet (load check) valves and he said they were ok.