Silicone Brake fluid vs. Regular Fluid

Canadian Poncho · A Poncho Legend!

Silicone Brake fluid vs. Regular Fluid

65 SD L79 · Canadian Poncho Superstar!

I like the fact you can spill it on your paint and it won`t eat it up.

ARCADIAN · Poncho Master!

I use synthetic Valvoline Dot 5 and as Kevin says if spilled and makes contact with the paint, no damage!

Lemans64 · Poncho Master!

I use silicone brake fluid, mostly for the paint damage thing, but also cuz it has higher boiling point. Headers are close to the brake lines. I beleive u must flush system completely to change over as the two fluids do not mix well. Also Silicone does not absorb moisture, but moisture will enter the system and puddle in the lowest point, so changing fluid every few years is still a good idea.

Canadian Poncho · A Poncho Legend!

I read you will get more of a spongy feel with Dot 5. Do you guys notice this?

ARCADIAN · Poncho Master!

Todd I haven't noticed any spongy feel. My setup has cross drilled/vented 11" rotors and low dust Hawk ceramic pads, wilwood proportioning valve, 9" power brake booster and Corvette master cylinder, stainless lines and dot 5 synthetic brake fluid.

65 SD L79 · Canadian Poncho Superstar!

I just did the 67 Mustang a month back and they are spongy but I don`t think we got all the air out of the system.

67BBSD · Canadian Poncho Superstar!

better get all that dot 3 out before putting dot 5 in--I've ran both never had trouble with either but yes dot 5 is better for not getting moisture in / higher boil point / no paint issues-----------but everyone that works on the car better know its dot 5 because if they add dot 3 there will be trouble

beaumontguru · Canadian Poncho Superstar!

I cant say enough bad things about it!

First. It is really expensive.
It is NOT compatable with any other fluids, so you better be careful not to accidentaly add dot 3 by mistake.

As mentioned, water will still pool at the lowest points, so whats the reall advantage after hearing that statement?

It builds air as you bleed it, and it is really REALLY hard to pressure bleed the system.

It gives a VERY low pedal, and a really bad spongy feel compared to dot 3.

Have you ever noticed that if you pour dot 3 on your fender, it WILL NOT eat the paint, unless you leave it on there overnight.
I mean, if you wipe it off right away, there is no harm anyway.

After installing dot 5, you will have to completely flush and blow the entire system for hours, once you realize you should have stuck with the good ol dot 3.

Only advantage is if you are racing a race car on a road course, you will not boil your fluid. Do you realy do that with a 40 year old pontiac anyway?

Trust me you will HATE dot 5.

Lemans64 · Poncho Master!

No spongy pedal in my car. Stock GM dual master with 9 inch booster, Stock 69 Gm disc brakes up front, drums in rear, could stop on a dime if u wanted. Pedal is nice and firm. After spending numerous thousands of dollars to get my car painted and accidently splash brake fluid on it and have it stain it would kill me.

DOT 5 For me :)

davelacourse · Poncho Master!

beaumontguru wrote:

I cant say enough bad things about it!

First. It is really expensive.
It is NOT compatable with any other fluids, so you better be careful not to accidentaly add dot 3 by mistake.

As mentioned, water will still pool at the lowest points, so whats the reall advantage after hearing that statement?

It builds air as you bleed it, and it is really REALLY hard to pressure bleed the system.

It gives a VERY low pedal, and a really bad spongy feel compared to dot 3.

Have you ever noticed that if you pour dot 3 on your fender, it WILL NOT eat the paint, unless you leave it on there overnight.
I mean, if you wipe it off right away, there is no harm anyway.

After installing dot 5, you will have to completely flush and blow the entire system for hours, once you realize you should have stuck with the good ol dot 3.

Only advantage is if you are racing a race car on a road course, you will not boil your fluid. Do you realy do that with a 40 year old pontiac anyway?

Trust me you will HATE dot 5.

Never tried it on a street car. It does have advantages for a race car. Sure is expensive (but that's how racing is, eh?). Always took more time than it should have (but that's how racing is, eh?) to properly bleed the system, but I did end up with a "right now" braking before the corners. And yes it is incompatible with 'regular' brake fluid and yes you do have to have a 'virgin' complete brake system before using it.

So, I agree with Winnipeg Dave a.k.a. beaumontguru, skip it for the street car, just be careful to not spill the DOT3 stuff on your fender, eh?

Dave

norontcan · Canadian Poncho Superstar!

Interesting conversation going on here.

I will be completely rebuilding the brakes on the wife's 66 Rustang soon. ( new dual master, 4 wheel cylinders etc ). Was strongly considering using synthetic fluid because it isn't hygroscopic. And because of the paint remover properties of DOT3.

Looks like I'll have to reconsider - or atleast research this further.

Any of you guys at the dealerships know what the new highend cars are coming equipped with?

Lemans64 · Poncho Master!

My car was a virgin system so I never had to flush it, But it is a street car. Never had any problem bleeding it. I drive it to work and to car shows for more than an hour at a time. Same brake pedal as day one. Same stopping power as day one.

Canadian Poncho · A Poncho Legend!

All new Toyota and Lexus use standard brake fluid.

beaumontguru · Canadian Poncho Superstar!

I should be more specific about the pedal "feel"

Its no so much as spongy feel. Its more a low pedal, or perhaps more travel.

It is actually a fact about dot 5, it creates a "low pedal" feel. I remember reading about it somewhere, that is a real characteristic of dot 5.

I have had Dot 5 in my chevelle wagon scince day1, and compared to all my other Dot 3 cars, the wagon has this "low pedal" feel, almost like Power Brakes.

You would probably not notice it, or think it is normal, I just have my other cars to compare to.

I know it is blead properly, its been in there, untouched for 11 years. So probably time to flush it, and check out the internals of the wheel cyls.
Then i will flush and dry the system and fill with dot 3 next time around.

Lemans64 · Poncho Master!

I'm a Tech by trade and work at a dealership as mentioned above, and have not noticed any diff in pedal feel, actually feels quite high. Different strokes for different folks.