Sheila Bair hasn't been FDIC chair for almost three years but neither the time away -- nor her new role as a director at Banco Santander -- has cooled her fire for tougher bank regulation -- nor dulled her famously sharp tongue.

The biggest U.S. banks "are still too levered," Bair says. "Capital levels have improved since prior to the crisis...but loan-loss reserves are down significantly as banks keep releasing reserves to drive earnings. They'll tell you 'credit quality is getting better, the economy is on the upswing.' I don't know about that. They need more capital [and] need to stop releasing reserves."

Bair is also concerned about banks' "off balance sheet assets" especially at firms "with big trading operations," i.e. J.P. Morgan (JPM) and Goldman Sachs (GS).

"They're funding with only 3%-4% common equity," she notes. "Any non-financial entity that only had 3%-4% common equity would be junk, in bankruptcy. People would laugh at that. It defies common sense these big institutions with all their complexity [and] all their challenges in managing have that level of capital and we can say 'oh that's enough'. It's not. It needs to be significantly higher."

How much is 'enough' is subject to debate but Bair supports a 2013 proposal by the FDIC to require leverage ratios of 6% for banks and 5% for bank holding companies to cover off balance sheet risks. "The good times won't last forever and [banks] need to be prepared," she says.

The financial services industry has been fighting this proposal, among many others, including a recent proposal by House Ways and Means Committee Chair Dave Camp (R-MI) to impose a tax on banks with over $500 billion in assets.

"The proposal has galvanized Wall Street in a way largely unseen since the financial crisis," according to The WSJ, which reports Goldman Sachs opted out of a fundraiser for the National Republican Congressional Committee because of Rep. Camp's proposal.

"Oh honestly...I can't believe those guys...the piling on," Bair says. "And where is the Obama administration? Their silence is deafening."

While preferring a tax based on transactions vs. asset size "the fact [Rep. Camp] had the courage to do that and the courage to step up with a tax reform proposal is good and should be applauded," Bair continues. "We should be engaged in a constructive dialogue with him as opposed to all these deep-pocketed Wall Street guys beating him up and nobody on the Democrat side even defending him."

Want to know what else makes Sheila Bair mad? Watch the accompanying video to find out.

Aaron Task is the host of The Daily Ticker and Editor-in-Chief of Yahoo Finance. You can follow him on Twitter at @aarontask or email him at [email protected].