pt. 1: Traced and tested everything i could- with out a Guage set. Machine suddenly wouldnt lift boom or tilt (up) bucket while driving- machine would stop and make a groaning whining sound similar to trying to move on very low throttle or accidently moving the control sticks when parking brake is engaged. Machine required full throttle (2800-3050 rpm) for any movement, despite seemingly normal boom and bucket function when parked. Replaced parking brake solenoid, electrical components, ran the old solenoid plugged into harness with new solenoid direct to battery w/ toggle, etc. Checked for hydro leaks and loose fittings & clamps, fluid level, etc. Unless you're a heavy equipment mechanic or research the living hell (like i did) out of documents and the net, you won't find this part mentioned, listed or showing up on Deere schematics or in their trouble shooting process- which states 'replace pump' if charge pressure is low. I'll replace this whole manifold soon, because i suspect the piston/cylinder clearance is excessive which caused the piston to cock in the bore and constantly bleed off 'charge' pressure; which not only releases the parking brake, but assists in brake application while the machine is running and also replenishes the drive motors. This valve is only mentioned in one manual on a diagram, but shows no exploded view. It is ONLY available already assembled in the hydraulic filter manifold assemble which i was quoted at $560 for. PT 2 shows the temporary fix.
