always to the rescue ddgonzal. its the twin master

Yes, if all four wheels lock, it suggests the master cylinder

One cause of locking is the pushrod adjustment. There must be at least 5mm play in the pedal to prevent lockups. See Brake Pedal Adjustment

Do you have a single master or twin master?

Hi guys,

Looking for some advice. My brakes keep binding, i barely made it home today. The pedal goes really hard with no travel, it does ease up over night but then gets crap again. Iv stripped the master cylinder and rebuilt it. It seems really good condition. but still the same thing. All 4 wheels are locking, not just one. so this has to be the masters fault right? It also seems to only happen when its warmer outside( warm for scotland is 15 degrees lol).
Any thoughts/help would be great

Andy