I recently had to replace a one inch hydraulic hose on my 20 ton hitachi zx 200 between the main pump and control valve. The hose no longer had any visible ratings on it and I had two options for replacement, 4000 psi rated hose and 6000 psi hose. I wasn’t sure what psi the machine runs at but found the system relief valve pressure spec online of 4980 psi. Knowing that, I went with the gold plated 6000 psi hose. Soon after, the 3/4 hose on return side of dippper cylinder went. It was marked with 4000 psi rating. The 1” dipper supply hose was also in bad shape so I decided to replace it while I was up there and it’s ratings weren’t visible. I replaced both of those hoses with 4000 psi rated hose. Can someone tell me what pressure these machines run at? If I only need 4000psi rated hose, I don’t want to shell out the extra coin for 6000psi hose which costs twice as much. The 4980psi system relief pressure is throwing me off.
Good day I suggest stick with the 6000 p.s.i. rated hose. Kind regards Uffex
Your max normal operating pressure is 4980psi, but when you hit that boost button on top of the joystick (power digging) it gives you 5260 for 10-15 seconds. That is when stalling a function.
Sounds like I’m sticking with the 6000psi rated hose and fittings, thanks for the input.