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DOT 3 or DOT4 Brake Fliud

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Interesting... perhaps my fluid is not getting any further then giving the top of my brake master a shiny coating?

Now I am curious... since I have dammage on my well from pervious spills or leaking from a pervious owner, perhaps I will test the SynPower with a little dab in an area that is already FUBAR.

How long do I need to leave some on the paint before I know it's eating, or not eating?
 
Aldwyn said:
How long do I need to leave some on the paint before I know it's eating, or not eating?
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Sorry, I don't know that one. I believe the damage does develop slowly, but no idea how slow.
 
So I don't need to worry about the DOT 5 and the small amount DOT 4 mixing and damaging the seals?

As I mentioned before, I think that all of the components have been rebuilt or replaced by now.

Does anyone know for sure if the synthetic brake fluid is harmful to paint?

thanks, Pete
 
69tr said:
Does anyone know for sure if the synthetic brake fluid is harmful to paint?

thanks, Pete
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That's strange you ask that question. I have some ruined paint under my brake master and I wanted to answer that same question so I tested them. I have a bottle of DOT 3 and a bottle of DOT 4 synthetic. I sprayed enamel paint on a piece of metal scrap. Let it dry for 2 days. Wiped the top half with DOT 3 and the paint came right off in less than 3 minutes. Wiped the DOT 4 synthetic on the bottom and I could NOT get the paint to come off. My test results seemed to show me that DOT 4 synthetic will not harm your paint. But I would always make sure to get it cleaned off ASAP anyway.
 
69tr said:
So I don't need to worry about the DOT 5 and the small amount DOT 4 mixing and damaging the seals?
Click to expand...
Nope, no worries. Although they are fully compatible, they will not mix at all. The DOT 4 stays separate.

I've done several vehicles now by just bleeding DOT 5 through the system, and the results have all been good. On the motorhome, new caliper seals were not immediately available, so I put the old seals back in (which had been leaking badly), and they actually stopped leaking. Donated the MH to charity some 8 years later; the new seals are still on my workbench /bcforum/images/%%GRAEMLIN_URL%%/smile.gif On the Chevy, a rebuilt caliper was available, and I never touched the hydraulics again in over 15 years and some 150,000 miles.
 
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