Front Brake Keeps Building Pressure/locking up

[old man roger]

I can't tell you why it happens to some reservoirs and not to others, but yes the fluid can get hot and expand causing the brakes to lock up.

For future reference, almost every city has a store that sells hydraulic hose. They carry every type of banjo bolt known to man for a hell of a lot cheaper than 11 bucks a piece, probably more like 3 bucks a piece.