Thanks RAY TECH, your comment is the most successful...
The oil and filter are new.
In this model is 7400 DC, the manifold is larger and with more components than 7400 AC.
The 7400AC is the load holding valve, it has a red **** on top.
In the 7400DC The load holding valve is different, dont exist the red **** to lower network manually.
Apparently the problem is the valve, the internal spring is damaged, not strong enough, and oil leak into the tank
Sorry for my little English.
Thank you for your comments and support.
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