I finished installing the new hydraulic pressure gauges a couple days ago and have been trying to bleed the air out of the system ever since. I cracked all the fittings at the main cylinders and bled out some strawberry fizz, but there's still air in the system. When I open the dump valve, I can hear the air and fluid mix surging through the lines. I've filled the pump reservoir several times, but the gear still isn't coming up or down solidly. I can only do so many cycles at a time without burning up the pump motor so after two days the action is getting a little better, but not even close to being right. Today I cycled the gear switch down and all three went down, but the pump kept running and the new LP pressure gauge read zero the entire time. Cycling the gear up only moves one of the mains partway up and the pump keeps running again and the HP gauge reads zero.

With one of the mains blocked in the up position with a stick, I could manually push the other main open and closed with the dump valve closed. That certainly doesn't seem right. (The nose gear didn't move during that exercise). I don't remember it being so hard to bleed the hydraulic system the first time I did it.

Or maybe something else is wrong? I guess I could isolate the gear one at a time to make sure a cylinder isn't leaking through at the piston seal, but it would have to be a massive leak, I think. I could also isolate all three gear and see if the pump, pressure switches, and my new pressure gauges are  working. Anybody have any ideas?

Here's a photo of the final installation of the pressure gauges in the center console: