Deere 270 stuck arm

I have a Deere 270LC the arm locks up, when I go to bring the arm in the main hydraulic valve is not letting the oil from the other side of the cylinder return to the tank, If I go and back off the relief valve from arm out side then the arm will come in, If I want to move the arm out then I have to back off the relief valve from the arm in and oil will flow back to tank and let the arm move out. Checked for a broken or stuck spool and found no problems. Machine was brought to me like...

Deere 270 stuck arm

Deere 270 stuck arm