John V. wrote:

From: Andrew B []
Flushing out old brake fluid with ATE Superblue.
Don't know how much fluid I need.


Jim replied:

Use a full liter. Once the can is opened you might as well use all of it to get a good flush. An opened can of brake fluid on the shelf is only good for recycling.


I don't disagree that it's a good idea to use plenty of fluid (cheap really) when you flush the system.

But-- The myth about a previously-opened can being no good is just that, a myth. The concern you have is that the fluid in the can needs to be protected from moisture in storage. Having the cap on is fine for this. The warning on the can and from many other sources is to avoid using fluid from a can that isn't sealed. To me that reads "If the can has been sitting on the shelf with no cap on it, don't use the fluid." This allows for one to be able to top up the car's fluid reservoir without having to run out for
a liter of Super Blue, and throwing the rest away.

For those reading at home: Flushing the old fluid out of the brake and clutch systems is the cheapest ticket you can find to eliminating hydraulic component problems with your car. Master cylinders, slave cylinders, and calipers will last pretty much forever with this little bit of care. Too bad hoses, especially wheel caliper hoses, and of course the infamous blue hose on 5-speed cars, get no benefit. Flushing also purges stray contaminants and air out when done correctly, making the pedal firmer and improving your second-stop capabilities over a contaminated system.

SoCal 928 Group members have easy free access to my flush gismo, the pump and cap thing that makes fluid flushing a snap. DR also sells one for cheap if you aren't withing bleeding distance of Los Angeles, works the same plus has a cute little pressure gauge on the bottle. E-mail me offline if you need mine.

dr bob


here you can easily see the level markers on the brake fluid reservoir:


Theo Jenniskens

1992 Porsche 928 GTS midnight blue