Francis “Jeep” Sanza, a beer truck driver and milkman who got his work experience driving for Gen. George S. Patton during World War II, died Tuesday at his Victorian home in downtown Napa. He was 99.

Sanza died in his sleep, said his son Nick Sanza. A framed picture of his former boss Patton was hanging in the dining room until his last day.

From the preparations for D-Day, in May 1944, right up through the landing at Normandy, the Battle of the Bulge and the final push into Germany, Sanza was at the wheel of an open air Willys-Overland with the four-star general in the passenger seat, tapping at the windshield with his riding crop.

“Everything he did I saw,” Sanza said during a video interview for Profiles in Valor produced by the American Veterans Center. “He was very good to me. He never scolded me when I was driving him.”

According to Nick Sanza, his father did not talk about his wartime experience until he was in his 70s. But Nick had also been drafted and served in Germany, and this common bond opened him up.

“When I lay down at night, it all comes back to me,” he later told a reporter from the Napa Valley Register.

Sanza was born Oct. 25, 1918, the son of a coal miner in Forestville, Pa. He was drafted into the U.S. Army in April 1941, was assigned to the 357th Ordnance medium Auto Maintenance Company, and was sent to North Carolina to field a small but rugged new vehicle made by Willys-Overland Motors.

The four-wheel drive transport, with removable rag top, went into production and came out as the “Jeep.” At a demonstration held at a secret location for the Supreme Allied Commander, Sanza drove the Jeep into a lake and underwater. When he came out soaking wet, he had earned his nickname — “Jeep.”

When Patton chose the Jeep as his recon vehicle for the planned landing in France, Sanza was recommended to be his driver, field mechanic and message conduit. Sanza customized the Jeep, adding bulletproof windows and a machine gun mount in the back. He also rebuilt the engine to make it faster.

He and Patton landed in July. From Normandy until Germany’s surrender, if Patton was in a Jeep, Sanza was behind the wheel.

“There were about 15 or 20 major battles they were in,” Nick Sanza said. “They were all over the place.”

Patton never called Sanza by his nickname. Sanza was simply “soldier.”

After the Battle of the Bulge, Patton was set to drive on and finish the job in Germany. In anticipation, Sanza overhauled the Willys, but Gen. Dwight D. Eisenhower ordered Patton to stand down and let the Red Army finish the job.

“He wanted Berlin so bad,” Sanza later told a TV interviewer. “When he got the word, you could see tears in his eyes. This is what he fought for.”

Sanza and Patton were together in Munich on V-E Day, May 8, 1945, and when the concentration camps were liberated. They never had their picture taken together because it was against regulations. But it would have been a good one, because he stood 5 feet, 7 inches and his boss was 6 feet, 2 inches.

After the Japanese surrendered in August 1945, military vehicles, including the Jeep Sanza drove for Patton, were hauled out into the Atlantic and dumped overboard. Sanza finished his tour in November and left the Army as a sergeant.

One month later, there was another driver at the wheel of Patton’s vehicle when it collided with an Army truck. The force of the crash caused Patton to fly up out of the passenger seat and hit his head on the ceiling. He had broken his neck and was paralyzed. Patton died of heart failure on Dec. 21, 1945, at age 60.

When Sanza heard the news, “he cried,” his son said. “He was very close to Gen. Patton.”

After his return home, Sanza went straight to Napa, where he had once gone to inspect a Jeep shipping facility. His assignment was long enough for him to meet and marry Evelyn Kramer, a “Rosie the Riveter” who was working on battleships and submarines at Mare Island.

They settled in Napa and Sanza got a job at the ammunition depot on Mare Island, where he worked until a beer distributor hired him as a driver in 1959. He eventually became a supervisor for the distribution arm of Olympia Beer. He worked there until 1975, when he and his wife formed a milk distribution company.

Working out of their home, the couple would leave before dawn each morning in separate trucks. They drove as a convoy to Clover Stornetta Farms to load up, then they split into separate home delivery routes. A few years later, they sold the routes and Sanza went to work for Clover Stornetta as a sales representative.

He lasted there full time until he was 96.

Sanza and his wife had lived in the same Napa house since 1963. At the entryway was a scale model of the type of Jeep he drove for Patton.

Once he started talking about the war, he was in demand. At age 95, he flew to Washington to tape an interview for the American Veterans Center. Two years ago, he spoke at the General George S. Patton Memorial Museum in Southern California.

He often drove World War II Jeeps in parades, but never owned one. He drove Cadillacs.

Survivors include his wife of 76 years, Evelyn Sanza; sons Nick of Napa and Frank Sanza Jr. of Sherman, Texas; and daughters Lavon Fagan of Napa and Chris McCall of Grass Valley.

A rosary will be said Sunday at 7 p.m. at Claffey & Rota Funeral Home in Napa. A full Mass will be celebrated Monday at 10 a.m. at St. John the Baptist Catholic Church in Napa.

Sam Whiting is a San Francisco Chronicle staff writer. Email: swhiting@sfchronicle.com Twitter: @SamWhitingSF Instagram: @sfchronicle_art