Worked on Hartle HBC750. Just FYI who doesn’t know: the adjustment on controls is not pressure relief but flow regulator. That one had blown counterbalance O-ring. Those metric but odd “half” size: 27.5x2.5 mm and 25.5x2.5 mm Motors case drain port adapter is: metric port/DKO. I suggest ordering O-rings and have them in spares because I think they get blown if someone screws up and forgets to open return shut off on excavator.
Sorry, that was Hartl, not Hurtl!
Fixed the typo.
Thanks!
Another thing I want to share: the first stage relief valve ( I’ll post a picture when I will figure out how to do it on this forum) small poppet valve looking thing with agjustment, has four small holes on its body radially. One of those have to be ligned up with a single hole in the control block body! There’s no groove. In the block, because those small holes used as fixed orifice flow restrictors. But if you don’t ligne on of them up than you will block the passage.
Well it’s just dawned on me that I might have missing crush washer, I’ll update you when I will find out for sure!
Yeah I just looked up what that thing is I have 0 experience on them I don't even know how they operate sorry I wish I could have been more helpful
I finally was able to communicate with the manufacturer of these things from Austria over Facebook messenger, but he said he needs to talk to his engineer tomorrow! Their website is down for three days in the row and he didn’t even know that.