I have a problem with my 2005 4520 where the PTO is not working. All of my other hydraulics are working fine, bucket, steering & rear lift, no problems. I replaced my hydraulic pump about 4 months ago. I thought the problem was the PTO solenoid, it was just replaced, and I've confirmed there is power from the PTO switch to the solenoid. I have the technical manual and it recommends checking pressure at 2 places on the PTO valve At front position on the valve it should be 214 psi, it registers "6". The back check point should measure 5.7, it registers "0". A new PTO valve costs over $1800 but I can order internal components. Before I do order the parts I want to see if any forum members have any suggestions?