To start with - I bent a hydraulic cylinder on my 4690 and posted awhile back trying to fix it: http://www.orangetractortalks.com/forums/showthread.php?t=27176. I ended up getting a shop to fix it for me (new induction hardened rod and new cast iron gland) and reinstalled it.
I got to thinking about the relief valves and when I switched the hydraulics between the 'dipper' and the 'lift' in order to get to the SAE style for the controls, I didn't switch any of the relief valves based on info I had read. However, it appears that the dipper and lift have the relief valves on the opposite sides of the stroke plus they're different pressure ratings.
*in the original location for the dipper there is a plug on the top of the control valve and a 2700 psi relief valve on the bottom.
*in the original location for the lift there is a 2000 psi relief valve on the top of the control valve and a plug on the bottom.
See below for pages from the backhoe manual...
Do you agree that I need to switch the relief valves and plugs to go along with my hydraulic line changes for the controls?
And do these relief valves go bad? If I've got to touch them anyways I might as well replace them.
View attachment BL4690A_backhoe hydraulic change.pdf
I got to thinking about the relief valves and when I switched the hydraulics between the 'dipper' and the 'lift' in order to get to the SAE style for the controls, I didn't switch any of the relief valves based on info I had read. However, it appears that the dipper and lift have the relief valves on the opposite sides of the stroke plus they're different pressure ratings.
*in the original location for the dipper there is a plug on the top of the control valve and a 2700 psi relief valve on the bottom.
*in the original location for the lift there is a 2000 psi relief valve on the top of the control valve and a plug on the bottom.
See below for pages from the backhoe manual...
Do you agree that I need to switch the relief valves and plugs to go along with my hydraulic line changes for the controls?
And do these relief valves go bad? If I've got to touch them anyways I might as well replace them.
View attachment BL4690A_backhoe hydraulic change.pdf