Question for Mr. Voni

[AKBEEMER]

In the recent article in ON I noticed that you changed brake fluid on average every third service. I'm figuring that equates to every 15 to 18K miles. Have I miscalculated? Is this really necessary? Are women in red particularly hard on brake fluid?

[PGlaves]

In the recent article in ON I noticed that you changed brake fluid on average every third service. I'm figuring that equates to every 15 to 18K miles. Have I miscalculated? Is this really necessary? Are women in red particularly hard on brake fluid?

I try to do it once a year - in the fall. The older bikes had that as an "annual maintenance" task. I think - I'm not sure - that on newest models BMW now says every two years, but that change might have been for coolant. Once a year is my norm.

[marchyman]

This link (bmwmc.net, pdf file) was just sent to me this morning by someone who had a question about brake bleeds. Short version:

rubber brake lines: every year
Stahlflex brake lines: every 2 years

[BMW Triumphant]

rubber brake lines: every year
Stahlflex brake lines: every 2 years

Thanks for the morning giggle. Won't be buying any of those Stahlflex self-destruct thingys anytime soon...

[marchyman]

Thanks for the morning giggle. Won't be buying any of those Stahlflex self-destruct thingys anytime soon...

When do they self-destruct?

[dbrick]

I think - I'm not sure - that on newest models BMW now days every two years, but that change might have been for coolant. Once a year is my norm.

The 2006 edition of the BMW Motorrad R12R Maintenance Schedule shows brake fluid replacement at two year intervals:

[BMW Triumphant]

When do they self-destruct?

Apparently, after two years. Seems ridiculously short time. Seems self-serving desire to sell more products.

All this IMHO, of course. Still, what could possibly be the reason for replacement after two years? Have never had to replace braided brake line, have you had to replace them?

[Lee]

Apparently, after two years. Seems ridiculously short time. Seems self-serving desire to sell more products.

All this IMHO, of course. Still, what could possibly be the reason for replacement after two years? Have never had to replace braided brake line, have you had to replace them?

Replace the brake fluid, not the brake lines.

[marchyman]

Apparently, after two years. Seems ridiculously short time. Seems self-serving desire to sell more products.

All this IMHO, of course. Still, what could possibly be the reason for replacement after two years? Have never had to replace braided brake line, have you had to replace them?

Perhaps I was a bit too succinct in my short version. How about this:

Replace the fluid every year if you have the rubber lines.
Replace the fluid every two years if you have the Stahlflex brake lines.

As for self destructing... The ones the came stock on my '05 GS are still going strong. Brake line failures haven't exactly been a big issue from what I read here. I don't remember reading of any, come to think of it.

[BMW Triumphant]

Clearly, i did not read the post carefully enough. Brain seized on brake line and never considered the line supplier was recommending a fluid change interval.

Technical reading skills need to be learned and then practiced. Seems i slipped on the latter.

Same with technical writing. We all need to be careful in providing adequate detail to try to prevent half-asleep readers going off on an unintended direction, as i obviously did.

[bikerfish1100]

As for self destructing... The ones the came stock on my '05 GS are still going strong. Brake line failures haven't exactly been a big issue from what I read here. I don't remember reading of any, come to think of it.

if your stock brake lines are not SS, they most definitely will self-destruct. die a slow death from old age, actually- but they certainly have a finite life span. AndyVH will likely chime in with more specifics as to process and causation- but it is a mistake to think that rubber lines will last forever.

[PGlaves]

if your stock brake lines are not SS, they most definitely will self-destruct. die a slow death from old age, actually- but they certainly have a finite life span. AndyVH will likely chime in with more specifics as to process and causation- but it is a mistake to think that rubber lines will last forever.

It is also a mistake to believe that "stainless braided" brake lines will last forever. Some will fail sooner than others, depending on how they are made. Some have a rubber lining, a stiffener, and a braided outer sheath. The rubber can still fail. It won't likely pop and spew, but it can swell internally and rubber bits can slough off clogging things.

[AKBEEMER]

OK, now I've been on a brake fluid change frenzie. Guess I've neglected this a bit. Three of five bikes done. Only the rear of Annie's thumper looked bad; sorta like day old Army coffee.

[98lee]

It is also a mistake to believe that "stainless braided" brake lines will last forever. Some will fail sooner than others, depending on how they are made. Some have a rubber lining, a stiffener, and a braided outer sheath. The rubber can still fail. It won't likely pop and spew, but it can swell internally and rubber bits can slough off clogging things.

That's why, if you are going to put stainless lines on your bike, make sure they are the more rigid teflon lined style.

[PGlaves]

OK, now I've been on a brake fluid change frenzie. Guess I've neglected this a bit. Three of five bikes done. Only the rear of Annie's thumper looked bad; sorta like day old Army coffee.

Ouch!

The appearance of weak apple juice is about as dark as I like to see it. But you didn't say chocolate syrup, at least.