Common Tread

What an investigation into Harley-Davidson brake failures means for the rest of us

Jul 08, 2016

If you follow motorcycle news like we do, you probably saw stories today about a National Highway Traffic Safety Administration investigation into brake failures on certain Harley-Davidsons. I think there's something in the news to think about even if you don't own one of those bikes.

The NHTSA investigation covers more than 400,000 Harleys from 2008 to 2011. The agency received multiple complaints of front and rear brake failure, including one from a rider who crashed into his garage door.

So what implications could this have for all motorcyclists?

NHTSA noted that Harley-Davidson claims the problem is a result of riders not adhering to the two-year service interval for replacing the brake fluid. Most brake fluid (the exception is DOT 5) is hygroscopic, meaning it absorbs moisture from the air. In their response, Harley claims that the moisture found in old, contaminated brake fluid can damage the actuator valves found in the anti-lock braking system. It is unclear at this time as to whether it was the anti-lock functionality of the system that failed or the entire braking system itself. 

Results of the official investigation notwithstanding, I find this interesting for two reasons:

First, I have had problems with the anti-lock function on ABS-equipped cars and motorcycles in the past, but that never affected the brakes' ability to slow the vehicle. If the initial claims are true, it sounds like what may have happened here is that the failure of the anti-lock braking system caused complete brake failure. 

ABS has come a long way since it was first introduced to motorcycles in 1988 by BMW. Today, we have ultra-sophisticated systems like the one on the BMW S 1000 RR I rode recently. It’s interesting to consider that old brake fluid could cause complete failure of these more complex ABS braking components.

This brings me to my second concern, which is the fact that I am not one to regularly change my brake fluid. If I were taking bets, I’d be willing to wager there are a few of you out there guilty of the same. We’re trained to change our oil, spark plugs, and air filters, but changing brake fluid is one of those maintenance chores easily overlooked.

I have owned my old Triumph Bonneville T-100 for 11 years and 74,000 miles and I have changed the brake fluid one time, when I updated the brake lines. Now in fairness, most of my bikes are older and void of ABS. I’ve had the calipers on my old Honda CB550 lock up from years of sitting, neglected, in the back of my garage, but I have never experienced instant brake failure as a result of a faulty mechanical or electrical braking systems.

Last year, however, I bought my first bike outfitted with ABS. With the amount of time I spend riding in the rain and splashing through puddles, let alone factoring in the brutal humidity we’re currently experiencing here in the Northeast, I am rethinking how often I change my brake fluid. Regardless of what you ride, I would recommend taking a look at your service records to see if it’s time to change your brake fluid. If you’re handy with a wrench, our very own Lemmy has a video that will walk you through the basics of bleeding your brakes.

Personally, I think I'll be bleeding my brakes much more regularly. Considering the price of brake fluid, it seems like cheap insurance to make sure you don’t end up riding through a garage door, or worse.