PC10-7 S/N 26009 If the machine isn't level, it will self rotate to the low side It's gotten worse, now the swing spool valve doesn't rotate the platform at all. There's a simple valve body powered by its own 1/3 section of the stacked pumps. One function is the blade, works great even at idle. No response from swing spool right beside it. Removed valve took to hydraulic repair shop It tested perfectly I'm leaning towards the swing motor is bad. Especially since it floats freely I don't have schematics but you can view the entire system with floorboards removed Here's the mystery: swinging the boom using the auxiliary foot pedal rotates the platform!!!! Maybe only 90 degrees. If the motor circuit is open, somehow the oil is backfeeding to generate this strange phenomenon!!??!!!???
You might have to post of photo of your machine. I've never seen a PC10.
Left hand joystick is swing and stick functions, the aux foot pedal to the right side swings the boom only. Next pic is main valve body. Last shows swing motor and 2 hoses connect to the dedicated valve for swing and blade only. Very simple design.
Now I know what you have. It's all manual linkages. The linkage for the swing should be manual and has rods that go down the pedestal the level is mounted to. At the bottom of that pedestal there is another set of linkages that work the left side aux pedal and the swing. I have a customer with a PC30 that looks the same as your PC10. It is a bugger to see under there but the four possibilities are the main pivot bolt for the linkage is partially out, a pin is out on the clevis that attaches the swing lever to the that linkage, one of the clevis joints are frozen or a reach rod is bent.
None of those items apply in this case. Thank you for your time.
I simply removed the swing motor, as it's very simple to unbolt, even tho it makes no sense because the aux boom swing function was able to make it turn, and the splines on the swing/Slew motor are broken. It's being repaired to see if anything internally is worth saving or if we need to replace the entire motor. I'll try to update soon. And whether there's still another fluke problem. Truth is often stranger than fiction. Right?