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Quote:

Dave,

Yes, it was interesting. I was actually a molecular evolutionary biologist, using DNA, RNA and other biological polymers to look at evolutionary history and the processes that influence molecular evolution.

I realize silicas and silicone are different, which is why my thinking wasn't too bright .

I am assuming that DOT 5 contains polysiloxanes, yes? Maybe in the form of -SiO-R where R is some sort of organic group like an acetate? I am also assuming that the R is hydrophobic? If so, a strong amphiphillic detergent might also work and be safer than stuff like xylene. We used to wash silane off of glass plates using Alconox. Silane is obviously different, but similar in being a silicon compound that is very slippery and water insoluble.

Just exploring ways to reduce the use of nasty organic solvents.

Tom

Tom, I really don't know what type of molecular structures are used to formulate DOT 5, seems like an interesting little sideline project for us to explore. But it surely is hydrophobic.

Hey PackardV8,

What other website will give you a $1,500 consult on your 10 word question? Especially, at these prices!

Big Kev wins the Concise Trophy (2 words = 'brake cleaner').

Thanks guys.

:) Dan

Chemistry was never one of my strong points. And besides, what little i know of Chemisrty is long before the time of Owen and Roadsta.

As for Big Kev's recommendation about the Brake Cleaner i really don't know. I've never used anything specifacaly formulated for cleaning brakes. My guess is that there are 2 different Brake Cleaners since there is the hygrascopic dot 3 and hydraphobic dot 5 ?????

In the past i have cleaned (DOT 3 system) brakes with gasoline or laquer thinner with excellent results.

I'll try Owens recommendation for Acteone in this DOT 5 situation i have.

BUT, it still raises the question: Why didn't the laquer thinner clean it if laquer thinner contains acetone???

As far as I know there is only one type of brake cleaner found at parts store. It comes in a spray can and costs about $3. It's basically just a really good degreaser. I use it on everything.

Yes, but there is a problem with silicone vs petrol or other based products.

For DOT 3 systems just use some gasoline or paint thinner. It's cheap and plentiful. SOME so called experts will throw a fit over the rcommendation of cleaning greasy brake linings with gasoline or thinner. I've done it so many times and actualy drove the vehicles myself many miles at high speed with excellent results and no failures.

My guess is that your Brake Cleaner in a bottle proabably has an alcohol, gasoline or Carbontetrachloride smell to it????? It has a reddish-brown hue to it???

OR, maybe i should have asked if the Brake Cleaner in a bottle specically states for use on DOT 5 and/or DOT3 or denies effectiveness on DOT5??? Maybe it's only good for cleaning away gerease???? I don't know. What i am trying to clean is DOT 5 brake fluid from parts. Not grease.

Here is the MSDS on the CRC Brakcleen brand brake cleaner that I buy from Autozone:

crcind.com.au/catalogue.nsf/(MSDS)/5089%20Brakleen%202007/$FILE/MSDS.pdf

I looked some stuff up, and if anyone wants to try it without using brake cleaner (acetone, naptha and propane) Alconox should work great and will be non-toxic.

I'd try it on my car, but I can't find where they brake fluid is kept.

Tom

p.s. The silicone is polymethylsiloxane.

I believe that alcohol (methy, ethyl or ispropyl) is the accepted solvent for cleaning DOT 3 (and presumably DOT 4 which is similar) brake fluid residues from hydraulic parts. I also seem to remember when converting a car to DOT 5 years back that alcohol was the recommended solvent to flush the steel lines and cylinders (all rubber parts replaced). Like others I had good success using gasoline to clean grease from contaminated brake linings, but never had much luck cleaning and putting brake shoes back into service that had become saturated with brake fluid, no matter what they were cleaned with. Nowadays with a few more $ in my pocket I wouldn't even consider it, new shoes are relatively inexpensive.

Back to PackardV8's question about lacquer thinner and acetone, I don't have formulation info in front of me for lacquer thinner but I think the major components are a chemical class known as esters (like methyl or ethyl acetate), not ketones (like acetone or MEK).