New hydraulics for the 8N

After many years of service then hydraulics on the ’51 8N needed some help. When the lift arms are raised and the PTO is then disengaged, the arms drop slowly. Since using an auger that is PTO driven is made very difficult due to the inability of the lift arms to stay up without the PTO engaged, some thing would have to be done. Rebuilding the lift assembly and pump were in order. So with rebuild kits in hand, disassembly commenced. The lift cover is quite a heavy piece, so an engine hoist was used to lift the cover to protect the arm from being damaged. It was also discovered that water had been introduced to the oil, which had turned a nice milky color since the last service. Investigation showed that the gaskets were not seal properly by whomever last serviced the unit. Also, the gaskets that should have been between the cylider and the lift cover were missing causing some leakage. It was also noted that the pump was leaking from multiple locations, including the safety valve. There was a large layer of goop at the bottom of the pump/PTO space which took some time to clean out by hand. I could have used a vacuum, but it was so thick that it would have taken some time to clean with that method. The scoop by hand method worked out well, then a bit of mineral spirits and some shop towels did the trick.
While at the parts store getting another batch of gakset sealer, a varient designed for gear oil was selected as a test. The downside is that a setting period of 24 hours is required before introducing oil. We will see how well it seals. There was a lot of build-up of dirt and oil (dried) caked on the axel and transmission housing that has to be removed by scraping. Pressure washing removed only the surface of the cake. Hopefully the leaks have been taken care of with new gaskets, although the left side cover was not removed, so that could be a future fix.
Re-assembly was tight as the pump requires precise positioning to get it back into the housing, a little wiggling and a pry bar moved it into the correct position without any damage. The casting of the pump assembly is a work of art, given the time that it was created and cast in aluminum, so care was taken to not damage it during re-assembly. Getting the lift cover back into place was not as easy due to its weight and awkward shape. Additionally the arm can be damaged if you are not careful and it has to be engaged to the pump properly before the cover comes to rest on the housing. Once all is back into place and bolted, adjustments can be made to ensure proper operation. Come to find out that the quadrant was seriously out of alignment, so loosening the four bolts for the adjustment and some nudging with a deadblow hammer got things lined up and moving per the manuals specifications.

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