Hello
Thanks for the info
Grey usually indicates brake fluid.
Since it just happened you may have a hose or check valve on backwards.
When you changed the valve covers did you disconnect the power brake unit vacuum hose? It has a one way check valve in it. Check the vacuum hose (with check valve) from power brake unit. Note installed direction for proper check valve operation (arrow on hose label faces engine).
Let me know
Thursday, December 24th, 2009 AT 11:21 AM