Brake fluid flush: how often?
10-04-2010, 02:34 PM
#18
Rennlist Member
If running standard DOT 3 or 4 fluid 2 years is OK.
If you are running high performance DOT 4 or 5.1 fluid then a MAX of 1 year.
I normally change mine every 6 months of so.
I have also been noticing more and more master cylinders failing from a build up of corrosion in the bore from a lack of fluid changes.
If you are running high performance DOT 4 or 5.1 fluid then a MAX of 1 year.
I normally change mine every 6 months of so.
I have also been noticing more and more master cylinders failing from a build up of corrosion in the bore from a lack of fluid changes.
Also, I HIGHLY recommend picking up a Motive Power Bleeder. They are fairly cheap on EBAY. Combined with lift bars I think last brake and clutch flush took less than 20 minutes. Its actually easier than an oil change now.
10-04-2010, 02:44 PM
#19
Nordschleife Master
Chris,
The higher the boiling point of the fluid, the more hygroscopic it is.
DOT5.1 fluid always has a higher boiling point.
The faster it absorbs water, the sooner it needs to be flushed out with fresh fluid to prevent corrosion.
The higher the boiling point of the fluid, the more hygroscopic it is.
DOT5.1 fluid always has a higher boiling point.
The faster it absorbs water, the sooner it needs to be flushed out with fresh fluid to prevent corrosion.
10-04-2010, 04:22 PM
#21
Under the Lift
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I don't use the brakes much (they slow me down), but I flush every 2 to 2.5 years.
It's traditional in the US to ignore brake fluid, like it lasts forever.
It's traditional in the US to ignore brake fluid, like it lasts forever.
10-04-2010, 05:44 PM
#24
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The other bad thing about 5.0 is that it is not hygroscopic like normal fluid. In fact it mixes with water as well as oil mixes with water - not at all. However the brake system still gets moisture in it because it isn't completely sealed. But the water just migrates down to the lowest points and stays there and slowly fills up.
10-04-2010, 05:54 PM
#25
Nordschleife Master
Sorry Greg, I am just checking on my phone. So no links. But if you spend some time studying you will undoubtably find the same information. In my eyes it is simply cheap insurance. And I do use my brakes rather hard esp when I get a beep beep 
10-04-2010, 05:56 PM
#26
Rennlist Member
Don't even think of putting 5.0 in your 928 unless you completely flush the system, renew all the rubber seals and plan on completely draining and changing the fluid every race/drive.
The other bad thing about 5.0 is that it is not hygroscopic like normal fluid. In fact it mixes with water as well as oil mixes with water - not at all. However the brake system still gets moisture in it because it isn't completely sealed. But the water just migrates down to the lowest points and stays there and slowly fills up.
The other bad thing about 5.0 is that it is not hygroscopic like normal fluid. In fact it mixes with water as well as oil mixes with water - not at all. However the brake system still gets moisture in it because it isn't completely sealed. But the water just migrates down to the lowest points and stays there and slowly fills up.
Yup..that sums up the whole nother story quite well...and its damned hard to fully flush.
10-04-2010, 09:06 PM
#27
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OK yes, my local shop owner has explained to me how the brake fluid collects moisture and can boil thus causing brake failure.
This was something unknown to me for many years, I think I drove my 944 for at least 6 years without once changing brake fluid. It turned out to be fine after that and it got more frequent changes.
Thanks for the tips,
Sean
This was something unknown to me for many years, I think I drove my 944 for at least 6 years without once changing brake fluid. It turned out to be fine after that and it got more frequent changes.
Thanks for the tips,
Sean
