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Brake Fluids Mix?

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Old Jul 22, 2009 | 05:39 PM
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argabright52's Avatar
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Question Brake Fluids Mix?

So I just put the Ness Foot Control Extensions on my 09 Nighttrain and used Dot 5 brake fluid instead of Dot 4 (I bought the wrong one by mistake and didn't realize until I already poured some in and started bleeding the brakes). I bleed the brakes until only purple fluid was coming out. After I got done, I started to wondering if this is going to cause any issues. What's the word on this one, leave it be or go buy some Dot 4 and drain the Dot 5 out? Anyone else made this mistake?
 
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Old Jul 22, 2009 | 05:53 PM
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I would flush the whole system and put proper fluid. You can mix Dot 3 and Dot 4, not Dot 5 fluid.
 
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Old Jul 22, 2009 | 06:19 PM
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You need to flush the entire system or the mixture of the two fluids will turn to gel and you will loose the brakes, or lock up the wheel.
 
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Old Jul 22, 2009 | 06:26 PM
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Originally Posted by Bowtieman31
You need to flush the entire system or the mixture of the two fluids will turn to gel and you will loose the brakes, or lock up the wheel.

 
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Old Jul 22, 2009 | 06:59 PM
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Default Brake fluid mix

Thanks for the quick replies from all. I just got done draining the Dot 5 fluid out. I'll go to the dealer in the morning to get some Dot 4 fluid. I assume the draining, then flushing with the Dot 4, then draining that and filling with new Dot 4 should work. Please let me know if there's any other steps I should take on this one.
Dave
 
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Old Jul 22, 2009 | 07:03 PM
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You may need to replace all of the brake lines, depends on how bad the fluid has gotten as it sat. I'm no expert, but the dealer might be able to tell by looking at it.
 
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Old Jul 22, 2009 | 07:09 PM
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You do not need to replace the brake lines. Just flush the entire system really well and you should be fine.
 
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Old Jul 23, 2009 | 07:27 AM
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i got dot 3 or 4 at autozone. i am sure much less than the dealer
 
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Old Jul 23, 2009 | 07:55 AM
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flush it and put the syn. brake fluid. i did something similar when i first bought my bike, i topped off the reserve with regular auto brake fluid, lucky it didnt make it to anything because from what i read it will destroy your brake lines. anyway i flushed the system and refilled with the syn and that was 8,000 miles ago. everything is still good.
 
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Old Jul 23, 2009 | 09:21 AM
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Dot 3,4 and 5.1 are glycol based. Dot 5 is silicone based, which is why Dot 5 doesn't mix and reacts with Dot 3,4 and 5.1 when mixed.
 
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