Does anyone has parts diagram for Hartl HBC750? I have a suspicion that I’m missing crush washer under first stage releif valve, need to confirm that. And I been told about some kind timing procedure on this one, does anyone have an idea about it?
Here’s so far what I know: Hartl give no support for the hydraulic side of things, they can’t even provide me with parts diagram of control valve for the motor, I’m still not approved for their web store, but I doubt they have hydraulic parts there ( beside hoses), the only way to communicate with them is through Facebook messenger! The manufacturer of hydraulic control is Italian company called Atlantic Fluid Tech. https://www.atlanticfluidtech.com/pages/product-catalogue/ The setting for 750 is: 350rpm at idle and 40 gpm from excavator. Sets by black plastic double knob on the controll block. Should post more updates as I find more information.
The motor on this thing is looks like Parker F12, but motor is up side down, and my phone can’t focused on the name plate to take a picture.
So the Italians came back: turns out primary relief valve (the small poppet looking valve with adjustment on top of the control block) was seriously over torqued! Be careful guys! The design of that valve is such: if you over torque it, you will damage the cavity inside of the block it self, and your pressure may start leaking to the drain side. It can be remedied by removing the thread on the valve ( bottom side) just a touch, and widening the o-ring groove the same amount ( so the o-ring would not get pinched by valve sitting lower. But I think you can do it only once - there’s not much room there! Other opinions will be re machine the whole cavity or replace the whole block. And I’m not sure which option is more feasible! The max torque on that one is: 27-33 N/m
These guys is AFT representative in the US https://www.flodraulic.com/contact