Brake fluid question

[Guillaume69 150]

Hi guys,

 

As I am about to fill in my brake system, I am looking at brake fluids. I was chatting with friends today and somebody mentioned DOT 5 brake fluid as being the best option. Not "water friendly" (ie not sucking moisture into the lines as condensation happens when brakes get "cold-hot-cold"), and having some type of silicone component which makes it less corrosive for paint. Just a little pricier ($25 a quart).

 

Can any of you confirm this?

 

I am running stock set-up (power front disc with booster and rear drums) except for metal braided hoses front (L and R) and rear (axle). Brake lines are new as well as master cylinder and rear wheel cylinders. No other fluid (DOT 3 or 4) has ever touched these lines or master cylinder.

 

Thanks for your help!

 

G

Edited May 17, 2014 by Guillaume69

[Brian Conway 264]

If you have never put any other fluid in your system. The DOT 5 is a good alternative and I would use it. Brian

[RPM 1,190]

Everything I've read on several forums recommends dot 3 or 4, and stay away from dot 5. They say the dot 5 is silicon and compresses, which is not desired in brake systems.

 

There are two boiling point numbers, dry and wet. The higher the number, the better since you don't want the fluid to boil. The dry number is new fluid without any water. The wet is older fluid with water in it.

 

You can buy fluid with around 475° dry boiling point for less than $20/qt. Should be fine, unless you race.

 

 

Bob

[Rsanter 152]

I use silicone dot 5 in two,of my cars and love it.

Yes it takes a little,to,get used to for not having a pedal that is very hard but there is not that much difference in feel.

I like,it because it won't eat paint.

It is my understanding that it dosent handle,heat as well so,do go track racing with it but I do autocross with the one car and it has been fine

 

I bought a bulk order to get a good price so if you need some let me know

 

Bob

[BuckeyeDemon 211]

i use dot 5 in mine. i would use it again in a heartbeat.

[bobh67 18]

Dot 5 is the only way to go. I have been using it for many many years in dozens of restored cars. In the midwest where we have 7 -8 months of not using our classics they SIT. If they sit, use Dot 5 NO moisture, no problems period!

[RPM 1,190]

Hey, I used dot 5 when racing karts and never had any issues. I love the fact that it doesn't destroy paint. I was just passing on my findings. When researching it, I was looking for supporters of dot 5. I never started a thread, just read them. Guess I should've posted a question here first :)

 

 

Bob

[MustangGT 11]

Another vote for silicone Dot 5! Pedal feel is different but worth it - not having to worry as much about the moisture.

[Midlife 814]

The only problem I've read about with DOT 5 is to not shake the bottle before adding it to the MC reservoir: bubbles are entrained and they take an awful long time for the air to come out of solution.

[Mister69 10]

Used DOT5 in both my cars, the first one 12 years ago. The fluid is still as clean as the day I poured it in. No signs of corrosion.

[stangs-R-me 120]

I've used Silicone DOT 5 in both my '69 and my '67 Fairlane since the mid 80's.

 

I had read somewhere that moisture will always get into brake systems especially on vehicles that are not driven regularly. So since Silicone Brake Fluid does not absorb water, they claim it will just pool in places within the system which is worse than having DOT 3 / 4 fluid absorbing it.

 

When I finally got around to replacing my brake lines in 2011, I drained all the 80's vintage fluid into a glass jar with lid and let sit for a while to see if there would be any water separation. Months later this 25 year old fluid looked just as "pink" as new fluid and I could see no separation !!

 

What originally attracted me to this expensive fluid was the fact that it does not harm paint.

 

Honestly don't know what the brakes in this car should feel like with regular DOT 3/4 so to me the brakes with DOT 5 feel 100% NORMAL.

 

I'm a firm believer in it, especially after seeing what it looked like after 25 years of being in a vehicle that has been driven less than 3700 miles since 1993. That averages only 176 miles per year, guess I better start driving her more !!

 

Doug

[Thunderscrash 10]

I've never used dot5 but I use dot 5.1 in my daily driver 2000 gt.it has a higher boiling point then the dot 3/4. It's not much more money either.

[Rsanter 152]

5 and 5.1 are not the same thing at all

Very deceiving and you can't mix them without big problems

 

Bob