Posted 8/5/2022 20:26 (#9782410 - in reply to #9782247) Subject: RE: How to disassemble / rebuild this hyd cylinder?
The master on the opposite side may not be bypassing at full extension as it should. In other words, you should be able to hold the raise control after the master cylinder reaches full extension and the slave should extend.
I have a 930 JD head that used to raise both sides of the reel evenly until I had the steel tube across the rear of the header connecting top of master cylinder to bottom of slave on the other side break. I brazed it back and still couldn’t get slave end to raise. Thought I had blocked the tube with the brazing, but when I blew compressed air through it I found it was open.
I have discovered the master cylinder does not bypass at full extension. I have had to fill the hoses and tubing between the cylinders with oil by connecting a hose to the whole circuit and plugging it into a tractor. After extending and bleeding the slave to get rid of all air, I lock the reel up on both ends, disconnect the line from the tractor and reconnect it to the master cylinder. Now it works like it is supposed to.
I’m not certain the master ever bypassed oil or not. Maybe the slave circuit and cylinder was always just full of oil.