Cleveland Brake O-Ring replacement?

[JoeyC]

Hello, so in the summer every 2 months my right brake would become really soft and lose pressure. No visible leaks and have bled and refilled it. Now that its gotten colder it really loses pressure quickly. I looked on Aircraft Spruce but can’t figure out what O rings to order (assuming that’s even the issue). Can anyone help with part #

 

[jimrice]

 

[bob turner]

 

[JoeyC]

 

[lycominglou]

 

[Jeff J]

 

[ralter]

 

[Jeff J]

 

[Jeff J]

 

[melnickj]