I have installed a new hydraulic pump Takeuchi OEM in my tb135 mini excavator. The pump has 4 outputs: P1, P2, P3, P4. P1 is working correctly. I set relief valve to 2900. I could not get P2 port to come up past 1000 psi. So I swapped the relief valves for P1 and P2. Same result. When I checked P3 relief valve I had about 1000 psi going through it and it would not raise the blade with that low of a pressure so I raised the pressure by adjusting P3 relief valve and it came up to 2k psi but is staying constant 2k psi pressure whether I am activating blade or not. This raised the PSI on the P2 port to about 2400 when it is activated P4 is showing about 400 psi constant which is pretty close to what it should be. As I understand P3 should not be showing constant pressure and P3 and P2 should be able to raise to its won pressure without "help" from P3. I have not attempted to drive or work the machine until I get these pressures where they should be because another pump costs 4k. All filters, and suction filter are new and fluid is new and pump is new. Any ideas?
Post the schematic
Here is the schematic pdf
There are 2 filters called adapter line filter in the top left of the drawing. I an curious where they are on the machine.
I wonder if they're under the arm rest ?, I replaced the joy stick on mine but didn't look under the pilot valve. I haven't seen a filter for the pilot valve lines anywhere else.
I have discovered the hydraulic oil from the p3 port is flowing into the two hoses on the valve block assembly no.7 which is the right side travel. Those hoses got hot with the machine just sitting at idle same as the p3 supply hose from pump. While the hoses for the left side travel were just barely warm. Now I do not know is how the fuild from p3 is flowing over into that section of the block assembly.
I'd block the pilot pressure feed of switch valve and check its operation and the inline filter to it as it sounds like the p3 isn't unloading. When checking p2 pressure how what circuit are you stalling ?
Well after all this. Here is the p3 spool from the valve block. The threaded end had backed off too far and the spool could not return to center
My next wondering is about this lock cylinder that sits under the crawler drive levers. It is supposed to move in and out, but mine is frozen. What does this do? Do I need a new one? Should I try to move it back and forth by hand? It looks like it has not moved in a long time.