I thought these systems were self bleeding? they come with some fluid from the factory and they instruct you to cycle it a few times to purge any air in the system. Than you top off the fluid. Am I missing something here? I know I saw an air bubble in my one hose but after a few cycles it was gone. With that said I only have 2 hours of experience on these machines.
It is an open system so just cycling it after filling the tank will take care of any air bubbles after a bit. Kero. to flush tank is fine or diesel fuel or fuel oil any of those will work.
Yes, its open in that the hydraulic tank is vented but air can still get trapped and can be difficult to remove. Its not a system that runs a hydraulic motor where the fluid circulates. Fluid flow to a cylinder dead ends and does not circulate, it only moves back and forth. If you replace a line and then air inside that line is pumped into the cylinder than air may get trapped in the upper portion (higher above ground level) of the cylinder because the fitting enters the cylinder at the side rather than the top. If it were me, I'd loosen the fitting on the cylinder and use the direction valve to pump hydraulic fluid towards that fitting via the new hose. That way any air would exit at the loosened fitting rather than entering the cylinder. Once only fluid exits at the loose fitting (no sputtering) tighten down the fitting. Maybe overkill but it can be real tough sometimes to purge air from a hydraulic system. You'll know when you have air in the lines because there will be a springiness to the cylinder action. Air compresses, hydraulic fluid not so much. I've got a man lift with an "open system" that's been plagued with air in one circuit to a cylinder for a while. No amount of cycling has removed that air.
I would not have thought of flushing the system with kerosene because I'd want to be sure I got it all out. I would think that there's a major difference in viscosity between kerosene and the hyd fluid. It should not harm the seals though. We've only had ours a few years, but haven't seen anything in the tank or filter that would prompt me to flush the system.
Update. I went to local Napa...took the old hoses and they made up new ones on the spot in less than 10 minutes. Very good service and fair price. Got home from work and got to work, drained old fluid (looked pretty good actually), changed filter, put on new hoses. Started it up (first pull), then ran a few short cycles, waited and then ran a few long cycles then turned it off. I checked the fluid level and it was where it should be since I filled it a little high since the lines were dry. Started it up and and cycled it some more, stopped and checked level again...all good. Split about 2o chunks of black cherry, it went fine...although mentally it seemed slower. Gave all my connections a once over and snugged everything up. I believe this has been a successful project. Thank you to all for your help.
usually just acts herky-jerky until it bleeds out . It's not a closed system like the brakes on your car.
How not? In both cases the fluid dead heads at a piston and then return to the fluid reservoir by the same line it came in. The only difference I see is that that the splitter is vented to the atmosphere through the reservoir fill cap and the fluid in the master cylinder is isolated from the atmosphere by an expanding reservoir seal. I don't mean to come off as argumentative and would really like to know if I'm mistaken.
