Brake fluid
 

Running regular fluid in my car now is there a way to flush and install silicone type fluid can i just clean out the master cylinder and push the new through ?

Yes, I did it on my cars... Empty your master cylinder of the old Dot 3, fill with silicone and push it through the system bleeding all four brakes until you see purple fluid, the silicone, and all the Dot 3 is washed out.

Not too bad to do just time consuming..

Rich

Why do you want to run Silicone fluid? Dot 5

Dave
67 Nova Boy

Dave, silicone is non corrosive, you can leave it in there for ever and not worry about moisture issues. Also if some accidentally spilled on a finish the silicone won't hurt anything, just wipe it off. Dot 3 is nasty stuff if it gets on something...

Rich

How about all the seals?

Rich,
This was quoted from another forum that says it better then I can...


Of critical importance in determining a fluids ability to handle high temperature applications is the Dry Boiling Point and compressibility.


The Dry Boiling Point is the temperature at which a brake fluid will boil in its virgin non-contaminated state. The highest temperature Dry Boiling Point available in a DOT 3 fluid is 572° F.

The Wet Boiling Point is the temperature a brake fluid will boil after it has been fully saturated with moisture. The DOT 3 requirement for wet boiling point is a minimum temperature of 284° F.

There are many ways for moisture to enter your brake system. Condensation from regular use, washing the vehicle and humidity are the most common, with little hope of prevention. Glycol based DOT 3 & 4 fluids are hygroscopic; they absorb brake system moisture, and over time the boiling point is gradually reduced. Here is a scary statistic, a new car at 12 months old will have a 2% water content if never driven, at 18 months it will be 3% or higher depending on atmospheric conditions. It is not unusual to have 8-12% water content in the average automobile on the street.

You should not use DOT 5 fluid in any racing application for the following reasons. DOT 5 fluid is not hygroscopic, so as moisture enters the system, it is not absorbed by the fluid, and results in beads of moisture moving through the brake line, collecting in the calipers. It is not uncommon to have caliper temperatures exceed 200° F, and at 212° F, this collected moisture will boil causing vapor lock and system failure. Additionally, DOT 5 fluid is highly compressible due to aeration and foaming under normal braking conditions, providing a spongy brake feel. DOT 5 fluid is best suited for show car applications where its anti-corrosion and paint friendly characteristics are important.

Whenever you add fresh fluid to your existing system (never mix fluids of different DOT classifications), it immediately becomes contaminated, lowering the boiling point of the new fluid. For maximum performance, start with the highest Dry Boiling Point available, flush the system completely, and flush it regularly, especially after severe temperatures have been experienced.

If you happen to mix DOT 3/4 and DOT 5 you will end up with a coagulated gel that will seriously compromise your braking performance. Dot 5.1 is a Glycol based fluid like DOT 3 or 4 and should not be confused with DOT 5 which is silicone based, many new European cars specify DOT 5 but in Europe they don't recognize the silicone based (DOT 5) fluid so they really mean DOT 5.1, ensure you don't confuse the two. DOT 5.1 was developed for ABS braking systems and is of a thinner viscosity to allow shorter cycle timing, it's boiling point is similar to DOT 3 or 4.

Another post to help all decide on what fluid to use and why.

http://www.chrysler300club.com/tech/...rakefluid.html

Dave
67 Nova Boy

Good info Dave thanks.

I have had silicone fluid in my 69 Chevelle and 70 Nova now for nearly 10 years and have never had any issues and I do drive both cars.

Rich

Brakes are not something to play with...most every one on this site has a classic car and would not like to here about one getting into an accident due to brake issue.

Very glad to hear your doing good with the dot 5 fluid...keep up with your maintenance on your brake system.

Dave
67 Nova Boy

Brake fluid
 

Excellent information Guys.

People think we are trying to up-sell them when recommending a brake fluid flush for their vehicle. Then later when the calipers lock up and need to be replaced, they complain about the expense. A very in-expensive service on any vehicle in the long run.

Bill