........leaky brakes in cold temps ATthe o-ring?

Setup is Tam F-16 wheels and brakes (Ibelieve the gear is Cermark because the retract frames are red? but the wheels are the white painted ones)

Of course the BVbrakes on my Bobcat do not leak at same temp but obviously the tolerances are tighter.

Ican confirm the cause because Ican heat the assembly with a hairdryer and it all but goes away.