Geo Hahn
Yoda
Offline
Disclaimer: I have yet to try this but certainly will the next time I need to do brake work.
Background - One issue with DOT5 is that it holds air in suspension much longer that traditional brake fluid. The bubbles may be t0o small to see but if they are there they can compress and enough of them will affect the pedal feel and brake performance. I suspect this trait accounts for some of the unsatisfactory results often reported by those who try DOT5.
One thing I usually do with DOT5 is let is sit quietly on the shelf for weeks or months to give any microbubbles a chance to rise out. But that isn't always practical and anyway I wonder how long is long enough.
On another forum a British car owner describes using a glass jar with a metal lid that had a single nipple fitted to the top:
The pump he shows looks like this:
https://www.avac.com/mityvac.php
Makes sense to me. Still requires a careful transfer of fluid from the jar to the reservoir but hopefully reduces the unseen microbubbles that shipping and careless handling introduce into the fluid.
Background - One issue with DOT5 is that it holds air in suspension much longer that traditional brake fluid. The bubbles may be t0o small to see but if they are there they can compress and enough of them will affect the pedal feel and brake performance. I suspect this trait accounts for some of the unsatisfactory results often reported by those who try DOT5.
One thing I usually do with DOT5 is let is sit quietly on the shelf for weeks or months to give any microbubbles a chance to rise out. But that isn't always practical and anyway I wonder how long is long enough.
On another forum a British car owner describes using a glass jar with a metal lid that had a single nipple fitted to the top:
...just the one nipple to attach to the vacuum pump. I 3/4 filled the jar with fresh DOT5 from the FLAPS, screwed on that... lid and put the contents of the jar under 15-18 inches of mercury vacuum. Sure enough, microbubbles came out of the brand new brake fluid, probably just from transporting it home. I did this to the entire litre of new fluid before using it. The brake pedal is now the same as I remember it was using DOT3 and the entire job took no more than ten minutes.
The pump he shows looks like this:
https://www.avac.com/mityvac.php
Makes sense to me. Still requires a careful transfer of fluid from the jar to the reservoir but hopefully reduces the unseen microbubbles that shipping and careless handling introduce into the fluid.
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