Not long ago, some people predicted that full interstate banking would make branches of New York banks as common in California neighborhoods as video stores and nail salons.

With the nation's biggest consumer banking market, a growing population and a strong economy, California for years has been viewed as lucrative new territory for out-of-state banks once the remaining barriers blocking interstate banking finally fall in 1991.

But now--as New York banks and other out-of-state institutions struggle with continuing loan problems--it's becoming increasingly clear that the big changes once predicted won't happen come 1991. And the way that some banking officials are talking these days, a proliferation of out-of-state bank branches may not happen for a long time.

"We have no plans to buy bricks and mortar in this state, and I don't think we would be immediately persuaded to do so," Willard C. Butcher, chairman and chief executive of New York banking giant Chase Manhattan Corp., said in an interview in Anaheim earlier this month.

Butcher's comments mirror the feelings of many banking officials: Full interstate banking may enter California with "a yawn," as Wells Fargo Chairman Carl E. Reichardt has put it.

There is limited interstate banking in California now. Banks in most Western states could buy banks in California, so long as banks here have the same right to buy banks in those states. And out-of-state banks are allowed to buy and operate thrifts in the state, as New York's giant Citicorp has done.

In addition, out-of-state banks can operate a number of businesses in California that do not need to be run out of a full-service branch. They can offer credit cards, make business loans and finance home purchases. The main barrier remaining is that they cannot buy banks and take in deposits.

That changes on Jan. 1, 1991. And the prospect of full interstate banking led many to predict an invasion by New York banks.

But banking executives now believe that any expansion by out-of-state banks into California may be blunted because of pressures on those institutions to conserve capital--the financial cushion that institutions must maintain to protect against losses. Concerns over having enough capital are especially growing at many banks in the wake of problems with Latin American loans and with increasing real estate problems in the Northeast.