No, by a stroke of luck, you won't have to carry your luggage. The redcaps apparently are not extinct.

After much public grumbling and a court injunction, Amtrak reversed itself yesterday, announcing that its decades-old redcap baggage handling assistance will continue for the foreseeable future at Union Station and nine other railroad stops from here to Boston.

Amtrak, the National Railroad Passenger Corp., warned last week that it planned to eliminate all 80 redcap luggage helpers in Amtrak's Northeast corridor, the stations between Washington and Boston. The cost-cutting decision - which was to take effect yesterday at Union Station - was intended to save $1.4 million a year.

The plan, apparently hatche dby Amtrak's Northeast corridor managers, was junked yesterday by Amtrak president Paul H. Reistrup, who, according to Amtrak's announcement, told corridor managers to "find other ways to cut costs."

Federal officials had already challenged Amtrak's move to do away with the redcaps.

In U.S. District Court here Monday, Interstate Commerce Commission officials charged that Amtrak had acted without notifying the ICC or the public of its plans. An ICC statement yesterday asserted that abolishing the redcaps would have "greatest impact" on elderly and handicapped passengers.

ICC officials also claimed Amtrak had "no cohesive plan" for helping riders with luggage once the redcaps were gone.

At 9 p.m. Monday, Judge John Lewis Smith Jr. granted federal officials a temporary restraining order, barring Amtrak from getting rid of the redcaps for 10 days. Amtrak officials had disputed ICC's contentions.

Amtrak's decision to retain the redcaps was described in an Amtrak announcement yesterday as "permanent irrespective of the outcome of legal action by the Interstate Commerce Commission."

While granting the redcaps a reprieve, Amtrak officials said yesterday that the railroad corporation may trim the number of redcaps on duty and may, at times, substitute other railroad worker for redcaps. Twenty-one redcaps and supervisors are employed at Union Station. Whether this number will be reduced has not been decided, an Amtrak spokeswoman said.

The now-defunct plan to do away with the redcaps was part of an Amtrak effort to reduce its deficit for the 1978 fiscal year by $50 million. Amtrak had already announced it will increase fares Oct. 30 on most passenger routes and cancel more than two dozen trains a day, almost all the busy Washington-to-Boston corridor.