Brake Fluid

[cubansolara]

I'm going to bleed my brakes soon. I need some advice on which brake fluid to use. I plan on bleeding them with Valvoline SynPower. Once the bubbles are gone, feeding the lines with ATE Super Blue Racing. I'll also be swapping the lines with the Goodridge's and pads w/ Porterfield's. Thanks.

[krook]

your manual should help you with that information

[impactX]

your manual should help you with that information

Your manual won't tell you what brand of fluid to buy..


Get Motul RBF 600 Factory Line: 593°F dry boiling point, 420°F wet boiling point... Enough said.

Or Motul Dot 5.1 brake fluid (it's DOT4) for ABS...

I would just get the RBF though...

[impactX]

For the Goodridge brakeline, make sure you have a 10mm flare wrench. Don't use an open end wrench.. You will know what I mean.

[JoeB]

Unless you are doing autocross or some VERY heavy braking that would bring your fluid temp to 900-1100 degrees, you should stick with a good quality Dot-3 brake fluid. Those really high grade brake fluids cost a lot more and don't have the lubricating quality the Dot-3 fluid has. They are also much more susceptible to contamination from humidity. Plus they need to be changed more frequently. The lack of lubricants makes those high-end brake fluids worse for seals, especially with anti-lock brakes. Don't you love getting advice to spend less money? -JoeB

[impactX]

Unless you are doing autocross or some VERY heavy braking that would bring your fluid temp to 900-1100 degrees, you should stick with a good quality Dot-3 brake fluid. Those really high grade brake fluids cost a lot more and don't have the lubricating quality the Dot-3 fluid has. They are also much more susceptible to contamination from humidity. Plus they need to be changed more frequently. The lack of lubricants makes those high-end brake fluids worse for seals, especially with anti-lock brakes. Don't you love getting advice to spend less money? -JoeB

900-1100 degrees? The fluid would be boiling beyond believe by then.

I think everyone who can justify buying a set of SS brakelines + semi-metallic pad can justify paying a bit more for some good fluids. The only good quality DOT-3 fluid I can think of is Ford DOT-3 Heavy Duty fluid and its dry boiling point is better than most DOT-4 fluid but it's nothing close to Super blue / Motul synthetic.

You don't have to change the synthetic often compared to normal DOT-3.

[JoeB]

I got the information from a guy that runs a performance shop and has been racing out in CA for a long time. You're correct, the fluid would be boiling at 900-1100 deg, that is what you need to avoid. The main purpose of the better fluids is to raise the boiling point. In doing so, they lose much of their lubricating properties. It won't get to that temperature though unless you are doing very heavy braking.

Steel brake lines are still a big advantage over the stock flex lines because of the lack of expansion. The brake response is better because of the lack of expansion. It would be exagerated if the fluid temp went up because the stock flex lines would expand more with the heat. I have S/S Goodridge lines on order and the money for the fluid certainly isn't the issue. If it was the "right" fluid for the application, I'd be all over it. However my understanding is, it is actually worse because it is harder on the seals in the brake system and much more susceptable to contamination from moisture. -JoeB

[impactX]

I got the information from a guy that runs a performance shop and has been racing out in CA for a long time. You're correct, the fluid would be boiling at 900-1100 deg, that is what you need to avoid. The main purpose of the better fluids is to raise the boiling point. In doing so, they lose much of their lubricating properties. It won't get to that temperature though unless you are doing very heavy braking.

Steel brake lines are still a big advantage over the stock flex lines because of the lack of expansion. The brake response is better because of the lack of expansion. It would be exagerated if the fluid temp went up because the stock flex lines would expand more with the heat. I have S/S Goodridge lines on order and the money for the fluid certainly isn't the issue. If it was the "right" fluid for the application, I'd be all over it. However my understanding is, it is actually worse because it is harder on the seals in the brake system and much more susceptable to contamination from moisture. -JoeB

I think you've mistaken DOT 5 (Silicone-based fluid) with DOT 3 and 4.

Any DOT 3/4 fluid system is interchangable. Think about it, if the fluid has a chance to damage the braking system, would anyone put it on their cars? There's a standard for a reason.

And even the best 5.1 fluid starts boiling at 600 degrees, when it reaches 900 degrees, you basically have no brakes already.