The Pentagon was preparing to ship one of its internal critics off to Alaska until it relented yesterday under pressure from Capitol Hill.

Col. James G. Burton, who has led the drive for more stringent testing of the Army's troubled Bradley armored vehicle, was reassigned to Alaska earlier this week. Burton repeatedly has argued that the personnel carrier has not been subjected to realistic tests.

But after intervention by members of Congress, a Pentagon spokesman confirmed yesterday that Burton will be allowed to remain with the defense secretary's office for another year.

When the possible transfer surfaced in September, four members of Congress, led by Rep. Denny Smith (R-Ore.), complained in a letter that Burton was being penalized improperly for his criticism of the Bradley.

Deputy Defense Secretary William Howard Taft IV denied this, saying Burton's job had been eliminated in a cutback. Taft assured lawmakers that stringent combat tests for the Bradley are scheduled this summer and that "Col. Burton will participate in the planning and execution of the tests."

The Pentagon spokesman said Burton was to be reassigned routinely after a three-year tour of duty. But the Pentagon's about-face did not come until after a flurry of phone calls from Capitol Hill.

According to an internal memorandum last fall, Burton said he was told that his superiors wanted "to pull in my reins because I was 'running too freely' " and that once reassigned, "I could move out or punch out."

The Pentagon plans to build up to 6,000 Bradley vehicles costing more than $1 million apiece. Congressional critics say the carrier may be vulnerable in combat because of its heavy ammunition load and aluminum body.

Among the tests cited as unrealistic was one designed to show that soldiers in the vehicle could survive enemy fire without burning up. Critics said dummies in the carrier were hosed down and stripped of uniforms.