Brake Fade: Can anyone point me to an article by an "autoritative" source?
07-30-2001, 12:20 PM
#1
AudiWorld Super User
Thread Starter
Join Date: Mar 2000
Posts: 2,716
Likes: 0
Received 0 Likes
on
0 Posts
Brake Fade: Can anyone point me to an article by an "autoritative" source?
I tried to explain to a fellow coworker that brake fade is attributed to your brake fluid boiling, and causing your brakelines to flex under pressure....
another idiotic coworker used the logic "you've never worked on your own brakes and therefore you're full of it... that's not true".
I know there's a couple of different types of fade (brake pads can glaze over), but can someone point me to a defninitave source... one that they won't pass off as being a random internet page?
another idiotic coworker used the logic "you've never worked on your own brakes and therefore you're full of it... that's not true".
I know there's a couple of different types of fade (brake pads can glaze over), but can someone point me to a defninitave source... one that they won't pass off as being a random internet page?
![hrana [AW]'s Avatar](data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 50 50'><circle class='avatar-circle-default' fill='%23b86055' cx='25px' cy='25px' r='20px'></circle><text class='avatar-text-default' x='49%' y='53%' fill='white' text-anchor='middle' alignment-baseline='middle'>h</text></svg>)
Trending Topics
07-30-2001, 05:20 PM
#8
AudiWorld Member
Join Date: Mar 2001
Posts: 111
Likes: 0
Received 0 Likes
on
0 Posts
Brake Fade is NOT boiling fluid...
Brake fade is when you exceed the temperature capabilities of the pad you're using, and the friction drops dramatically.
It's damned hard to boil DOT 4 brake fluid. You'd be surprised at how many people mistake pade fade as boiling fluid (then wonder why it still happens afer they flush out the old - clean - fluid.)
GregA
BIRA.ORG<ul><li><a href="http://www.bira.org">Brake Improvement Research Association</a></li></ul>
It's damned hard to boil DOT 4 brake fluid. You'd be surprised at how many people mistake pade fade as boiling fluid (then wonder why it still happens afer they flush out the old - clean - fluid.)
GregA
BIRA.ORG<ul><li><a href="http://www.bira.org">Brake Improvement Research Association</a></li></ul>
07-30-2001, 06:52 PM
#9
It's easy as hell to boil DOT 4 brake fluid...
...I do it nearly every time I go to the track. My Hawk Blue pads on the other hand, probably are just getting warm by the time my fluid's boiling.
07-31-2001, 04:39 PM
#10
AudiWorld Member
Join Date: Mar 2001
Posts: 111
Likes: 0
Received 0 Likes
on
0 Posts
Think so...?
If that is the case, then you have some serious problems with your car. I doubt you do.
Fresh DOT 4 fluid boils at around 500 or so degrees Farenheit (assuming you're not using a more-expensive version, like Motul, Wilwood, or AP). In order to get the fluid that hot you would have to transmit that heat into the caliper body. To get there it would have to go through your pad material, through the pad backing plate, through the caliper piston, and into the caliper body. At 500+ degrees your piston dust seals would be melting, the paint would be flaking off the outside, and the caliper pistons and o-rings would likely be damaged. At 500 degrees, your stock rubber brake lines would get soft enough to possible fail.
Have you witnessed any of these symptoms?
Granted, brake fluid boiling can be a localized phenomena, and can only happen immediate adjacent to the caliper piston, but the surrounding caliper body and brake fluid would be getting DAMNED hot and you would know it.
If you truly think you're boiling your fluid, I encourage you to invest in some caliper temperature gauges (stickers) as well as rotor temperature and pad temperature paint, all available from any racer shop. You can document to yourself that you are getting your brake calipers to temperatures exceeding 500 degrees.
I think what you'll find is that you're fading the pads (I fade Hawks all the time in much smaller cars than yours), but the only way to prove it is to properly test and document it. Further, until you test and document it you will never know how far you'll have to go (or what you have to do) to solve it; you'll just be pissing money into the wind...
Greg Amy
BIRA.ORG
Fresh DOT 4 fluid boils at around 500 or so degrees Farenheit (assuming you're not using a more-expensive version, like Motul, Wilwood, or AP). In order to get the fluid that hot you would have to transmit that heat into the caliper body. To get there it would have to go through your pad material, through the pad backing plate, through the caliper piston, and into the caliper body. At 500+ degrees your piston dust seals would be melting, the paint would be flaking off the outside, and the caliper pistons and o-rings would likely be damaged. At 500 degrees, your stock rubber brake lines would get soft enough to possible fail.
Have you witnessed any of these symptoms?
Granted, brake fluid boiling can be a localized phenomena, and can only happen immediate adjacent to the caliper piston, but the surrounding caliper body and brake fluid would be getting DAMNED hot and you would know it.
If you truly think you're boiling your fluid, I encourage you to invest in some caliper temperature gauges (stickers) as well as rotor temperature and pad temperature paint, all available from any racer shop. You can document to yourself that you are getting your brake calipers to temperatures exceeding 500 degrees.
I think what you'll find is that you're fading the pads (I fade Hawks all the time in much smaller cars than yours), but the only way to prove it is to properly test and document it. Further, until you test and document it you will never know how far you'll have to go (or what you have to do) to solve it; you'll just be pissing money into the wind...
Greg Amy
BIRA.ORG