Stablizer cylinder locked Cat TH-63

[U8u812]

I was using my TH-63 today, and one of the stabilizers locked in down position and won't lift. The cylinder is about 75% extended, and will not raise or lower more. Seems like the lock valve is set. I can move the machine if I tilt it all the way over, lifting the stabilizer foot so it barely touches ground. Another bit of info, I just replaced the 4 long lines from stabilizer control valve to junction just before the stabilizer assembally. I did cycle them a couple times, but is it possible it locked due ot air in system? The manual says to bleed it by cycleing, which I did, but maybe not enough.

Any idea what is best way to unlock lock valve, can I loosen a line? One of the lines is very stiff and seems to be under pressure. With machine tilted, & foot off ground, there should be no pressure on cylinder other due to lock valve. There is no access to lock valve release nut without removeing the whole cylinder.

 

[U8u812]

Well, I guess I jumed the gun on lock valve diagnosis. I switched the electcal terminals at control valve, and I got the lowered stabilizer up. So it is probably switch or control. I assumed it was air in the lock valve because I had just replaced those line.