Where can i purchase hydraulic lines for excavator in US?

[liftmys10]

I received bunch of nuts and bolts as well as various elbow fittings but unfortunately no tube. I did some research and it's PA11 nylon tube. You can also use PA12 nylon tube. Commonly known as nylon 11 or nylon 12.

So when I replace that tube going from the valve to one of the cylinders, the air is bleeded out automatically because it has pressure on both sides of the piston? Do I need to do anything else except make sure the new hose has fluid inside and try my best to not introduce air in the system?