Some of the people who engineer our massively complicated cars and trucks seem to have blown it … again. What might happen this time out? Your brakes could fail.

Honda said Friday nearly a half-million sedans and minivans in the United States were involved in this week’s recall to fix brake fluid leaks.

The action, announced earlier, involved the same issue that led Toyota to recall 1.5 million vehicles.

It’s important to emphasize that there have not been any accidents or injuries related to the recall problem, at least as far as Toyota corporate in the U.S. knows.

We were not able to contact Honda, but other sources confirm their recall will be for 2005 to 2007 models of Acura RL, and 2005 to 2007 Honda Odysseys (with drivetrains similar to those of the Toyotas called back home by their maker).

Brian Lyons, Toyota’s director of Safety and Quality Communications, told us exclusively that both the Toyota and Honda problem, as similar as they seem on the surface, could be related to the same parts coming from the same Japan-based supplier. To my eye, it’s a real responsibility; at least that was one of the first questions I asked Lyons who was, when we spoke Friday morning, a little busy … as you might expect.

Here’s what they think causes the trouble (based on, Lyons said, the research they’ve done so far, from Toyota’s point of view): It comes down to a problem with the brake system master cylinder and the fluid which it holds. You know it and have seen it; the little, clear plastic reservoir is usually located at the top of the engine and might be mounted on either side. And it holds that mysterious dark fluid.

That’s the brake fluid vital to stopping the car; it needs to be free as possible from any air and/or other contamination. Brake fluid (aka hydraulic fluid) is created with special lubricating properties including the inability to absorb moisture. A lot of these types of “magic” items were originally developed for the military (such as Mobil 1 engine oil, created for the Space Shuttle). 

Five years ago, the first reports of “spongy brake pedals” started trickling into Japan’s Toyota dealerships. Then more reports, and more ever since, though there’s been a slowing in the most-recent years (Toyota says that’s probably because dealers have been making a “fix” on their own and/or owners are pouring in upgraded, thicker brake fluid on their own, which can work for a time — like thicker engine oil cutting back on leaks out of the engine’s top end).

Research began. Soon we’ll know whether it began too late to avoid property and/or vehicle damage, or if there will be claims of injuries or worse. Those who have committed document shredding and obfuscation as part of their jobs will be asked to raise their hands for the traditional, humiliating wrist slap (car-maker and customer alike).

Toyota was using different brake system parts and fluids from one supplier. The problem was showing up in one of the master cylinders using a specific, single type of brake fluid (of the two Toyota was using in these cars).

Toyota found the fluid in one type of cylinder contained polymers (extremely sophisticated lubricants) of a certain type and quality. The polymer “content” varies with the fluid being used, much like the “10-50” numbers, for example, you decide to use when changing your engine oil.

After a time, this fluid level drops, the brake warning light comes on, some people visit their dealers and a fix is done. Ignore the light, the fluid leaks more and drops to a point where the pedal gets very spongy and the potential for a failing hydraulic brake system is certainly possible.

This all gets very complicated as there are questions to all the cars affected by the recall. Do they merely lose their anti-lock brake systems and everything reverts back to simple, safely-working hydraulics? And what about the brake-by-wire, involved in the recalls earlier this year? It dramatically cuts the number of components and the complexity of the brake system. Does it, too, revert to a no-worry back-up, too?

All this will come to light as the story unfolds.

Back in the system, the pesky brake/hydraulic fluid leaks into something called the “brake booster” and also gets absorbed in other system components. It all lowers the level of this important fluid which, when operating correctly, allows 90-year old Grandma to literally, after all is said and done, push on the brakes as hard as her 16-year old great-grandchild. 

The fix takes two hours, is absolutely free and involves new fluid and one part. All dealers ask is that you make a reservation with them; first you and the dealer should determine absolutely that your car is among the damned … uh, I mean, recalled. Registered owners will start getting those dreaded recall notices within the next two weeks.

One thing in Toyota’s favor: they got right out in front of this one, taking the lead in “coverage” of “their problem.” Toyota’s Communication Manager Lyons told me right off the bat during our lengthy conversation that, “We never stop investigations in our systems” and even if it’s ultimately found the problem lies with the brake system or fluid manufacturer, these types of things are “not supplier based, but ours.”

Which is exactly what Dr. W. Edwards Deming, the very tall and patrician man who developed the secret train schedules for the U.S. during WW II, would have said, and meant it. And is why the Japanese auto industry turned into the giant it’s become, until it admittedly gave into the arrogance and greed which some claim is inevitable.

 Steve Parker is a two-time Emmy Award-winner who has covered the world’s auto industry and motor racing for over 35 years. Contact Steve through his own automotive issues website at www.SteveParkerMotoring.com.