PEORIA, Ill. (AP) _ A historic tower clock that has greeted customers of a downtown brake service business for a quarter of a century is returning to the county courthouse, where it first marked time back in 1878.

''They didn't even want it 25 years ago and were willing to let it be destroyed. Now they're going to bring it back and display it in the courthouse. That's progress for you,'' said Martha Vachon Beck, whose father, Foster Vachon, saved the clock from destruction in 1964.

Since its rescue, the 1,800-pound clock has become a kind of landmark at Vachon Brake Service, where it was perched on the roof.

Vachon salvaged the clock from the old courthouse in 1964 as wrecking crews demolished the classic old limestone structure, modeled after Independence Hall in Philadelphia.

He mounted three of the clock's eight-foot faces, with their brass Roman numerals, atop his brake shop.

The cast-iron clockworks, a mesh of gears and wheels which resemble a large printing press, were installed in the front window under the clock. And a 15- foot deep pit was dug in the shop floor for the weights and the 500-pound swinging pendulum.

About a year ago, the Vachon family sold the brake shop and began thinking about the future of the clock.

The county will display the clock inside the three-story courthouse lobby as a link to the 19th-century era of riverboats, breweries, vaudeville, gambling and heavy industry.

Mrs. Beck said her father would be pleased to know the clock will be displayed so everyone can get a close look at it and enjoy it as he did.

''Dad would really get a chuckle seeing it back at the courthouse,'' she said. ''I know he'd be happy.''