After a cleaning the fuel tank and fitting the fuel tap we managed a short bit of running of around a couple of days until the time came to use the plough again and the hydraulics would not lift.
For a year or so we noticed adjustment may be required for the hydraulic system as operating the main control leaver became less responsive, the upper stop on the quadrant was actually removed to allow the main leaver past to allow the full lift for the implements.
As usual the breakdown was not in the most convenient location being in the middle of a field. After checking the oil level, which was very very low we decided to lift the top cover as something didn't look right. First impressions were not good. The remaining oil was thick and had emulsified in to lumpy mayonnaise, obviously a problem so no new oil was going in there without a good clean down. Our attention then turned to the hydraulic lift cylinder and control mechanism which looked barely serviceable covered in rust and the qualitrol selector leaver was seized. See images below.
A number of months passed and in September 2009 we decided to get the old girl in to the workshop and make some progress. A couple of day were spent spooning out the remains of the oily goo from the transmission and hydraulic pump housing. The PTO shaft was removed to gain access in to the rear diff section as the oil is shared with the hydraulics. The rear hydraulic mechanisms were removed and stripped, cleaned and regreased ready for painting. One of the automatic hitch vertical link rods had been bent years ago so with the help of the sledgehammer and my Grandfathers forge anvil we set the rod true.
The hydraulic control gear gave more of a fight to take apart; all the cotter pins and clevis pins were rusted in solid. The control quadrant was ceased on to the shaft - all problems to overcome.
By the end of September the Hydraulic control components in the top had been stripped cleaned, lubricated and repainted. A repair job was carried out on the main control shaft housing (to lift quadrant) where we had to cut and opening to get the woodruff key from the shaft - removing that woodruff key was the most infuriating thing so far.
The hydraulic lid is back together after sourcing suitable replacements for the destroyed clevis pins. New cotter pins fitted all round along with all new O-rings and a new return oil filter. Both the return and relief pressure valves were stripped, cleaned and reassembled.