If President Carter is to keep his campaign promise to reform the civil service, he must have not only the necessary legislation, which has just worked its way through Congress, but also a dedicated, corruption-free Civil Service Commission to act as watchdog.

And he must also, of course, have a determination at the top levels to rid the system of political corruption and to protect whistleblowers who refuse to follow the time-honored Washington maxim, "Go along to get along."

A confidential report, which we have obtained, casts serious doubts on the likelihood of the last two ingredients being included in Carter's recipe for the much-needed reforms.

The report, prepared by Deputy Assistant Attorney General Robert L. Keuch for Rep. John Moss (D-Calif.), details the rampant political favoritism and other illegalities that flourished during the Nixon administration. It shows how top commission officials not only let it happen, but then ordered the evidence destroyed - and explains why, despite these irregularities, the Criminal Division of the Justice Department chose not to seek indictments of the officials involved.

Ironically, the decision not to seek indictments was based on the fact that the crucial evidence of political influence in senior-level appointments was destroyed in a so-called "clean-up" of personal files. The officials who ordered and carried out the file-stripping insist to this day that what they did was proper.

The lack of evidence "could severely cripple chances for successful prosecution," the Keuch report informed Rep. Moss, adding: "There appear to be insurmountable hurdles to establishing beyond a reasonable doubt that anyone in the CSC corruptly intended to destroy government property or obstruct the congressional inquiry" that led to the file-stripping in the first place.

Complicating the Justice Department's inquiry was the fact that even the stripped files "have long since been destroyed per regular CSC destruction schedules and the purged material was thrown out," the Keuch report states.

The most fascinating case in the Civil Service Commission scandal involves Wade Burger, son of Chief Justice Warren Burger. He applied for a GS-14 position as special assistant in the General Services Administration in October, 1970. The first examiner to rate Burger's application, Robert Shuck, "found Burger not only unqualified for GS-14 status, but to rise no higher than the GS-9-11 level, and he refused to yield to pressure from his superiors to certify him," the report states.

But when congressional investigators reviewed the Burger file in August, 1974, Shuck's conclusions were strangely missing. Instead, it appeared that the first commission official to review Burger's application was Charles Ryan, who was in charge of "special referral and placement activities." A "pink tag" from Ryan's office was a signal that a particular application was to be "expedited," and as the Keuch report notes, "'expeding' cases . . . was tantamount to improper preferential treatment."

In September 1975, in a sworn deposition, Ryan "virtually conceded that he had provided preferential treatment to certain applicants as part of his official duties with the commission," the Keuch report states.

It was not until a conscientious internal investigation was conducted that the existence of Shuck's unfavorable rating of Wade Burger became known outside a tight circle of top commission officials. By then, the Shuck material itself had disappeared, and no one, including Shuck, could shed much light on what had happened to it, notes the Justice Department report.

Meanwhile, thanks apparently to on-the-job training, Burger was home free. Commission officials had concluded that while the Chief Justice's son had not been qualified for GS-14 rank, "he is now fully qualified for the position he holds."

The incredible "file-stripping" incident was also first discovered by the internal investigation, conducted by Milton Sharon and a team of commission employees from October 1975 to May 1976.

The Sharon Team, as Keuch's report refers to it, uncovered a January 1973 memo from William Irvin, manager of the Bureau of Recruiting and Examination for the Washington district. Irvin had been asked to make available about 30 files to a House committee investigator looking into charges of favoritism in the recruiting of high-level officials by the Transportation Department and the Courts Administrative Office.

"Please make sure that we do not have any extraneous notes or comments in these files," the Irvin memo said. His subordinates interpreted "extraneous" in the broadest possible sense.

They stripped out buck slips, pink tags, telephone messages, letters from congressmen - anything that might have looked like an instruction to "hire this person." They also removed "notes to the files" from commission examinaters - handwritten comments, some of which were obscene or ribald. The "notes to the file" may have been removed, the Keuch report states, because they "may have come from disgruntled examiners who were protesting pressure they felt from their superiors in rating particular applicants. . ."

Although the facts of the file-stripping incident have long been known to Carter Administration officials (we first reported on it last December), Keuch's confidential report to Rep. Moss is the first official disclosure to outsiders of all the details.

Unindicted and unpunished, responsible Civil Service Commission officials - and their counterparts in other federal agencies - may perhaps be forgiven if they interpret their continuing state of grace as a sign that "politics as usual" will still control the distribution of choice government jobs. The only lesson they may have learned is that when you want to say "Hire this person," just don't put it in writing.