launch delay is manifest

Lab testing after reviewing Endeavour's problem with the gas pressure
valves. Same issue already led to swapping parts in Discovery.

From http://www.msnbc.msn.com/id/29003183/

"Engineers are confident that the three valves in Discovery are good —
inspections show them to be strong and free of cracks — but want to
take extra steps to make sure no serious damage could result if one of
them broke during the 8 1/2-minute climb to orbit."
[...]
"Top NASA managers decided on the delay Tuesday evening after an
entire day of closed-door meetings at the Kennedy Space Center to
discuss launch preparations."

- - - does anyone have a good link to graphics about this problem?
Such as location diagrams?

/dps