Brake fluid purge and refill.

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Denpar
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Brake fluid purge and refill.

Post by Denpar »

I've upgraded my front drums to A40 8" and I now need to bleed the system. I intend using Dot 4 fluid but as I don't know whether or not the existing fluid is of the silicone variety am I correct in thinking that the existing fluid needs to be completely purged.

If I am correct how do people suggest I go about the purging process?

Roy
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Neil Evans
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Re: Brake fluid purge and refill.

Post by Neil Evans »

The different fluids feel different to the touch, so put some of each on your fingers to get a feel for it. They also smell (and taste... :whistle: ) distinctly different as well, though I wouldn't recommend the latter...

That said, since you're planning to use Dot 4 it wouldn't matter hugely if there was a trace of silicon in the system. It's more of a problem going the other way... :thumbs:
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Re: Brake fluid purge and refill.

Post by Hoppend »

Neil Evans wrote:though I wouldn't recommend the latter...
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Re: Brake fluid purge and refill.

Post by gazza82 »

If it has been in there for a while it is likely to be dirty, so bleed off each wheel until you see new fluid clean coming through.

It might also be worth draining/sucking out as much old fluid from the master cylinder reservoir first (a turkey baster is useful although it's original use is no longer recommended afterwards!) Then you know the fluid coming through is new and it won't take as long.
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Denpar
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Re: Brake fluid purge and refill.

Post by Denpar »

Thank you all for your replies. Turkey badter ready; will start a bit later today.

Roy
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