Getting rid of DOT5 silcone Brake Fluid

[DB Z28]

Going with DOT5.1 How do I get rid of completely of silicone dot 5 fluid. I was going to Flush brake lines out brake Clean wash out master cylinder and take Rear brakes apart and wash out any other Ideas. I also got new front brakes and lines

[shmoov69]

Not sure how much has to come out "completely", does it not mix at all?

Also, why is the reasoning/benefits?

[DB Z28]

It does not mix

[a67]

I would use denatured alcohol to clean, flush, and wash the interior of brake components. It won't harm the seals and such.

Bob.

[hotrodneb]

It is going to be quite difficult to remove ALL remnants of the DOT5 without disassembly. That being said, the alcohol mentioned above, and a blow gun dry is likely your best solvent. Brake kleen would also work I would think.

[shmoov69]

Ok, doesn't mix but what's the reasoning?

[DB Z28]

Bought a Kore C-6 Brakes set up and they don,t Recommend Dot 5 silicone fluid

[parsonsj]

DOT 5 silicon brake fluid is for show cars. It doesn't eat paint, and can go for a long time without acquiring appreciable moisture. Sounds good, but its actual performance is poor compared to regular glycol-based fluid.

http://www.tbmbrakes.com/silicone_br...al_brake_fluid

[OG_Racing]

whats wrong with dot4?

[Skip Fix]

I think like the questions about breaking engines in with synthetic oil or non detergent 30 W only there is some question in my mind on the "cons" of silicone brake fluid being real. My 78 TA has had hard autocrossing in CP for years and drag racing slowing down form 125mph with silicon fluid and never had a bad unpredictable pedal.

[shmoov69]

Thanks JP, I'll have to see which DOT 5 mine is. I know I changed it before doing the MMCC a few years ago.

[parsonsj]

My 78 TA has had hard autocrossing in CP for years and drag racing slowing down form 125mph with silicon fluid and never had a bad unpredictable pedal.

Those activities are pretty easy on brake fluid. Both are over in a minute or two, your brakes and fluid don't get that hot, and there is plenty of time for your brakes and brake fluid to cool down between runs.

Even so, I'll bet you'll have a better pedal with DOT 3/4/5.1 fluid.

[DB Z28]

I had Dot 5 in the car for 20+ . almost years and not have a problem except for the seals almost every 7 years leaks on the one of the rear disks other wise it was good

[72BBSwinger]

Motul RBF600 in mine. I like it, but it will definitely remove paint almost instantly.

[icemanrd19]

Old thread but I’m looking for experienced feedback

This year I plan to autocross my car a lot more. The 7 or 8 times that I have so far my brakes worked great with dot5 fluid in it. This year I plan on autocrossing a lot more and running optima. My question is the dot5 fluid that I have safe for racing? I am not rebuilding my entire brake system either. I figured I would be able to vacuum bleed the entire system of dot 5 and replace with dot 4 and everything would be fine. Any advice?

[shelteredchevelle]

I flushed a system with dot5 in it with a gallon of 4 and just pulled it through each corner 3 times, then pedal fed it a couple more times. It's been absolutely fine.

[icemanrd19]

Honestly that is what I’m thinking. I have a vacuum bleeders so I’ll just buy a gallon or two and flush it out.

[dontlifttoshift]

That won't get it done. I highly recommend the denatured alcohol flush 2 - 3 times and then flush with DOT 4 and then push your favorite race fluid through.

[67King]

I went through all of this with my GTO, sheesh, 25 years ago? Long story short, I had to replace and rebuild everything. I have heard of people successfully flushing, but I'd recommend against it. I'm assuming you are running all aftermarket calipers, most of those are easy enough to rebuild. The problem is with teh rubber parts. All of the lines and metal stuff can be flushed out quite easily. But the rubber stuff doesn't flush as well.

FWIW, DOT 5.1 and DOT 4+ (racing stuff) are nearly identical. The only reason I have ever come across for 5.1 was the newer McLarens dicated it as part of the ABS. I would also highly recommend against Castrol SRF. WOrks okay for race cars, but absolutely MUST be replaced in 12-18 months, or it will gum up and turn jelly-like. I use Millers Oils racing stuff because I used to be the NA distributor, but the Motul is the same, as are a few others.....there aren't many manufacturers of the stuff, all the oil companies buy it and put their own packaging on it. I also prefer it because it comes in 500ml bottles, so you don't have to open a full 1L of it to do a flush.

[GoodysGotaCuda]

Old thread but I’m looking for experienced feedback

This year I plan to autocross my car a lot more. The 7 or 8 times that I have so far my brakes worked great with dot5 fluid in it. This year I plan on autocrossing a lot more and running optima. My question is the dot5 fluid that I have safe for racing? I am not rebuilding my entire brake system either. I figured I would be able to vacuum bleed the entire system of dot 5 and replace with dot 4 and everything would be fine. Any advice?

I was told by Wilwood that all seals had to be replaced in the calipers and master cylinder, along with a new proportioning valve after flushing the system.

Unless you're having pedal issues, you may want to leave it alone. Throwing some ducting to the brakes may help curb it.