That defeat in the second rubber means the series is now beyond their grasp but McBryde insists there is still plenty to play for at the Allianz Stadium this Saturday.
Victory would be just reward for a season of hard work and huge progress and the former Wales hooker has told the current generation to focus on the positives ahead of what could be a defining weekend.
"It's a long way to come and return home with nothing to show for all the hard work,'' said McBryde.
''It's our final chance. But we've got to put a touch of realism to it all.
''We were just 40 seconds or a minute short of winning that game. As much as there were certain aspects we didn't get quite right, it did boil down to the last two minutes - it was that close.
"It's quite hard to lose in those circumstances but it's quite heartening to know that we were that close to getting what would have been a quite famous victory having not won here for so long.
"The players have been to the World Cup and proved a few doubters wrong. They backed it up with a successful Six Nations and they are all about creating a little bit of history for themselves.
"And this is their last opportunity. But it speaks volumes about the group that we're no longer content with pushing teams close - we need a win.
''We weren't that far away…we have to take heart and confidence from that andlook to go that one step further on Saturday.''
Waleswon't have it easy this weekend, though, despite the fact that the Wallabies have the series in the bag.
McBryde doesn't envisage any sense of complacency in the Australian ranks and he is after another massive effort from his men as they look to make the round the world journey home a little more enjoyable.
"They are used to winning against us, that's a big factor," added McBryde.
"And they'll keep on going until the very bitter end because they don't want to be the first southern hemisphere side to lose at home to Wales (in the professional era).
"So they are going to dig deep and the unfortunate thing is we gave them an opportunity to come back on Saturday.
''Up front they're obviously looking at getting across the gain line more than what they did on Saturday. I thought we were quite comfortable in dealing with the threats they posed, especially around the edge of the rucks.
''The inclusion of (Waratahs lock) SitalekiTimani shows they are looking for bit more of a running threat, and perhaps more weight in the scrum.''