Astronaut Douglas Wheelock, applying brute force to shake a balky connector loose, successfully demated a final ammonia line from a failed coolant pump module today, setting the stage for the pump's removal and eventual replacement.

Because of a significant ammonia leak in the M3 connector during a spacewalk Saturday, Wheelock and Tracy Caldwell Dyson were unable to complete preparations for the pump's removal, leaving the line in place pending additional troubleshooting.

Today, the astronauts planned to first close a quick-disconnect fitting on the outboard end of the S1 truss to isolate the line leading to the M3 connector. But Caldwell Dyson was unable to depress a release button, preventing her from closing the outboard quick-disconnect.

Flight controllers then told Wheelock, anchored to the end of the space station's robot arm, to press ahead with an attempt to simply close the leaking M3 connector in hopes that lower pressure in the line, the result of earlier ground-commanded nitrogen venting, would reduce the leakage enough to disconnect the line from the pump.

To the relief of anxious flight controllers, the connector closed easily and no major leakage was observed.

"I don't see anything leaking," Wheelock reported.

"Excellent," replied Oscar Koehler from mission control in Houston. "And Wheels, if you see any leak, we're comparing this leak to what you saw when you first did the SPD on EVA-1.

"OK, I see a couple of little snowflakes," Wheelock reported a moment later. "But I don't see anything leaking around the white band like last time. ... OK, here they start to come out now by the white band, just little snowflakes."

The leakage quickly diminished and flight controllers told Caldwell Dyson there was no need to continue work to close the outboard quick-disconnect.

"That's great news," Wheelock said.

"It's awesome," Koehler agreed.

A few moments later, with no observable leakage, engineers decided there was no need to install a vent tool to release any residual ammonia that might be trapped in the line. Wheelock was then cleared to remove M3 from the pump module.

But in keeping with M3's now-familiar behavior, Wheelock was initially unable to pry the fitting apart using a lever tool.

"We believe there may be ice in there that's keeping it from releasing," Koehler advised. "So you've got a go to ... move the QD left to right to try to shake some of that ammonia ice out of there."

After working the fitting from side to side with no success, mission control told Wheelock "you've got a go to shake violently, that's the words I was given, in all directions."

Television views from Wheelock's helmet camera showed him energetically shaking the fitting from side to side. After multiple attempts, the connector finally released and Wheelock pulled the M3 line away from the pump at 10:23 a.m.

There were no obvious signs of problems with the connector and the astronauts were cleared to press ahead with their pump removal work. Five electrical cables will be demated by Caldwell Dyson before the astronauts loosen four bolts to free the pump from the S1 truss.

If all goes well, the pump will be mounted on an attachment fitting at the base of the station's robot arm transporter.