NEW YORK – Every car in the U.S. after 2011 has had to be equipped with electronic stability control thanks to Federal Motor Vehicle Safety Standard 126. This means they all cars have four-wheel antilock brakes (ABS).
But not too long ago, many cars had no ABS at all; More interesting, though, is an intermediate phase between those two periods—a phase in which vehicles had rear-only ABS. Yes, that was a thing.
It’s a bit baffling to me, since one of the main advantages of ABS is the ability to maintain steering under braking, as this (strangely robotic) YouTube video from Bosch India explains: https://youtu.be/7aPLDsIrN9Y
I mention this only because, after writing about the holy grail of GM minivans—the manual transmission, Quad 4-equipped Pontiac Trans Sport—I received an email from someone named Kaz, who wanted to tell me about how amazing early 1990s Mazda MPVs were.
Kaz is totally right, by the way, which is why my coworker Andrew wrote a whole story on these incredible off-road vans. These MPVs had locking center differentials and skid plates, which is pretty incredible.
This email sent me down what the kids are calling a “rabbit hole,” and now I know more about early 1990s, manual transmission 4×4 Mazda MPVs than I’ve ever wanted to. This deep dive into the MPV brought me to one of the most 1990s commercials I’ve ever seen: https://youtu.be/mhDccBMygYk
“Its V6 engine and rear anti-lock brakes let you handle even the worst weather with confidence,” the narrator says before we learn that a team of unconfident children won a game not because of talent, but because the other team forfeited.
Yes, you read that quote right. Rear anti-lock brakes.
I’m sure the old-timers among you, and some of the young-timers, think I’m a child for not knowing about the existence of rear-only anti-lock brakes. But I’m sure I’m not the only ignorant person out there, so let’s talk about this weird system.
It’s known as a “one-channel” braking system, and it’s as simple as it gets. As the Clemson University Vehicular Electronics Laboratory writes on its website, this setup uses “One valve and speed sensor located on the rear axle [to]monitor both the rear wheels. This type of ABS is commonly seen in pickup trucks.”
Pretty straightforward. There’s a single valve that shuts off pressure to both rear brakes based on input from a single speed sensor in the rear axle or possibly in the transmission or transfer case. Plus, there’s a pump to build pressure, and a computer to control it all. Very simple and very cheap.