2155 brake bleed problem

[GR Gold]

A little history on this tractor. I purchased from a local municipality that owned it since new. The nose of the tractor had been pushed back some and cracked the fuel tank. Some disassembly happened and then it was abandoned. I removed the nose, fuel tank, radiator, etc., and replaced several hydraulic hoses up there as well as the fan belt and hyd pump drive rubber cushion, and a good fuel tank. I also had to replace the left brake line that runs by the hydraulic filter as it was bent and ran under the filter and the line cracked when I was trying to bend it out of the way. Fast forward to now. I have replaced the hyd filter and several hoses, and refilled the Hyguard. The hydraulic reservoir and oil cooler were drained when I replaced the hoses. Following the owners manual on bleeding the brakes, it says to run the engine at 2100 rpm for 2 minutes “ Thus making sure the brake reservoir is filled with oil”. I have a clear tube on the bleed screw and the other end has about an 18” piece of copper tubing that is stuck down in the oil through the fill cap. I have cycled the 3 point several times and turned the steering back and forth from lock to lock, so I believe the hyd system is functioning ok. Problem is, I cannot get the brakes to bleed. When I open the bleed screw a bit and cycle the brake pedal up and down, I cannot get all the air out. I get spits of fluid through the hose, but mostly air. I have done this for at least an hour. It looks like the supply source for the brakes is the small line coming off the hyd reservoir and running back to the “y” and down to the brake pedal area. I am not sure what the “brake reservoir” is that the manual is referring to. Is there another thing I should attempt to bleed here? I sure am getting frustrated. Thanks in advance for all your replies!