First car I ever had or saw with a return system was my 70 440-6. AND IT WORKED. I know because for some reason I removed it......................................................I remember........
Had an electronic pump I can NOT remember the name of, and it never shut off. Turns out that was design. I thought the return was the problem and pulled it off LOL. First few hot days (I was stationed in San Diego at NAS Miramar then) it would lock