Hello roadrat
Your problem is the check valve take it out end problem is gone.
There are many problems with it
Normally there staying 0.3 Bar on systeem buth when you start its gone and the brakes release and you drive normal.
But when the valve not good work he has 0.3 and the brake wil stay on and your pedal is hard.
Thake the valve out and you will feel the difference.
Regards.
John.
Netherlands
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