jzimmer238
New User
The hydraulics on my 1948 8n does not build enough pressure to lift an older, heavy bush hog on its own. If I assist it will raise the bush hog to the top of the cylinder travel. When I shut the tractor off with the bush hog lifted up it will stay in the air for over 2 days.
The tractor has fresh TSC Mineral Gear oil. There was no water in the 80W-90 that the TSC oil replaced. When I pull the inspection cover I notice turbulence in the oil so I plan to replace the pressure relief valve.
When the tractor is started with the inspection cover removed you will see air bubbles start to form on top of the hydraulic oil at the back of the pump. After the tractor runs for a while there is enough air in the oil that the oil level rises and will run out the bottom bolt of the inspection cover. I have searched and have but not found any posts specific to air in 8n hydraulics. What would be a likely cause for the air bubbles? Their is also a pin hole leak from somewhere on the top of the left hand valve assembly. Even with the 80W-90 oil there was not enough pressure built for it to lift the mower into the air on its own so the oil is not the main problem.
I have the top cover off now and the cam has a deep groove and the pin is worn half way through. The lift control lever has an 1.25" bow. I am going to remove the pump and disassemble. What should I be on the lookout for in the pump regarding the air bubbles and the low pressure?
The tractor has fresh TSC Mineral Gear oil. There was no water in the 80W-90 that the TSC oil replaced. When I pull the inspection cover I notice turbulence in the oil so I plan to replace the pressure relief valve.
When the tractor is started with the inspection cover removed you will see air bubbles start to form on top of the hydraulic oil at the back of the pump. After the tractor runs for a while there is enough air in the oil that the oil level rises and will run out the bottom bolt of the inspection cover. I have searched and have but not found any posts specific to air in 8n hydraulics. What would be a likely cause for the air bubbles? Their is also a pin hole leak from somewhere on the top of the left hand valve assembly. Even with the 80W-90 oil there was not enough pressure built for it to lift the mower into the air on its own so the oil is not the main problem.
I have the top cover off now and the cam has a deep groove and the pin is worn half way through. The lift control lever has an 1.25" bow. I am going to remove the pump and disassemble. What should I be on the lookout for in the pump regarding the air bubbles and the low pressure?
