The Federal Reserve Board, continuing its fight to stem inflation and shore up the dollar, yesterday boosted the discount rate to 8 percent, equaling its previous record.

The increase may have little actual impact on monetary policy, but it is viewed as a signal that the Fed continues to be willing to push up the interest rates to battle rising prices.

The nation's central bank said the quartder-point increase was needed to bring the discount rate - the interest it charges on loans to member banks - into line with other short-term interest rates, which have been rising steadily since late April.

The Fed's action puts added pressure on the Carter administration to unveil its tougher anti-inflation program, which Carter has promised he would deliver soon.

Federal Reserve Board Chairman G. William Miller publicly has called for wage and price guidelines, which are under consideration by the administration. Miller says such guidelines would relieve some pressure on the Fed in the inflation fight.

Both Miller and administration officials fear that continued increases in interest rates could choke off the economic expansion and lead to a recession.

So far, however, because loan demand from businesses and consumers has remained strong, rising interest rates have done little to curtail borrowing.

But at some point, many analysts say, the Fed will push interest rates too high, as the central bank has done in the past, making a recession a real possibility.

Since late April the Federal Reserve has raised short-term interest rates by 1 3/4 percentage points. The Fed does this by buying and selling government securities in the open market.

By raising short-term rates and making borrowing more expensive, the Fed hopes to cut down on the growth of the money supply - currency in circulation and checking accounts. The growth of the money supply is thought by most economists to be a key factor in inflaion.

The Fed also has pushed up interest rates to make U.S. securities more attractive to foreigners and to encourage Americans to borrow money abroad at relatively low rates.

Both actions would help soak up excess dollars abroad and, in turn, help curtail the decline in the value of the dollar against foreign currencies.

But the desire both to slow the inflation rate and strengthen the dollar may force the Fed to raise interest rates at least another half-percentage point by the end of the year, Leon Gould, an economist for Commercial Credit Corp., said yesterday.

Analysts anticipate that the prime rate, the interest banks charge their corporate customers for short-term loans will rise from 9.5 percent to 9.75 within a week of so.

The last time the discount rate reached 8 percent was April 1974, during the middle of the severe credit crunch that preceded the worst recession since the Depression.

The Fed has raised the discount rate five times this year, the last time in mid-August when it increased the fee from 7.25 percent to 7.75 percent.

In recent years the Fed had used the discount rate as a signal of what it has done in the open market. When the central bank wants to raise interest rates it sells government securities, thereby absorbing funds that banks otherwise might lend.

The Federal Reserve yesterday unanimoulsly approved the increase in the discount rate.