Mercedes and Brembo say that they still don’t know what caused Lewis Hamilton’s front brake disc failure in Hockenheim – but the two companies say that investigations are ongoing.
In an unusual joint PR statement they said: “There is currently no clear evidence of a single cause of failure and our continuing rigorous analysis will take into account multiple factors which could have contributed to the incident.
“The results of this technical analysis will be communicated as soon as they are available. Formula One is a domain of advanced development where technologies are pushed to their limits and in which strong partnerships are crucially important.”
The companies say that they “remain committed to a close working relationship in the future.”
Adam Cooper's F1 Blog 
Then both Mercedes cars will be withdrawn on safety grounds till cause and remedy are found?
No they can use use another supplier