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11,905 Posts
Discussion Starter #1
Car was at 33,000 miles and time for the recommended brake fluid flush. So I bought a Stoptech Stage 1 brake kit that includes fluid and lines, and a set of Brembo cross drilled front rotors and installed. Used my Motiv brake bleeder from :

and it worked like a charm.

Been about 100+ miles.

Brakes feel nice and firm, better than they ever were from the factory. The ABS no longer kicks on (and pulses) when I brake hard. Overall very satisfied.

A note on the brake fluid:

Changing brake fluid is very often overlooked as if its in there it must be good right? Wrong. Brake fluid is hydroscopic (meaning it absorbs water out of the atmosphere). While this doesn't mean much to many people, it does have a negative effect on your cars braking capability.

Good info:

General Information about Brake Fluid

Brake fluid is hydroscopic (absorbs water). When fresh from the can, it can be considered "dry" with the higher boiling point. That's why racers and people doing driver's schools change the brake fluid just before events. Over time, brake fluid absorbs water lowering its boiling point to the "wet" level.

For street cars, wet boiling point numbers are more important than dry because the fluid stays in your car for quite a while (one to two years). After a few months, with exposure to humid air, the brake fluid performance is probably closer to the wet than dry point.

Brake Fluid Recommendations

Brake fluid is one of the most overlooked aspects of brake system maintenance - but needs to be changed more frequently than most people think for two reasons, maintenance and performance. It generally takes about a quart to flush the system.

Changing old brake fluid removes water from the brake system. Brake fluid is hydroscopic, it absorbs water. Old brake fluid must be flushed out or water absorbed by the fluid eventually causes internal rust on the disk calipers and pistons.

Changing old brake fluid helps high temperature operation because fresh (dry) brake fluid has a higher boiling point than older (wet) brake fluid. If brake fluid boils, compressible gas bubbles form, resulting in a very spongy brake pedal.

Normal or Fleet Applications - Use a high quality fluid such as Z-Rated® that comes in a metal container and meets DOT requirements. Change with every brake job or every six months to one year - whichever comes first - to provide the maximimum stopping power and avoid that mushy pedal feel.

Competition (motorsport) Applications - Change your Z-Rated® or Castrol SRF before every race.

DOT Specifications:

<table border="2" cellpadding="0" cellspacing="0" width="366"> <tbody><tr> <td></td> <td align="center" bgcolor="#666666"> DOT 3

</td> <td align="center" bgcolor="#666666"> DOT 4

</td> <td align="center" bgcolor="#666666"> DOT 5

</td> </tr> <tr> <td bgcolor="#666666"> Dry Boiling Point

</td> <td align="center"> 401F

</td> <td align="center"> 446F

</td> <td align="center"> 500F

</td> </tr> <tr> <td bgcolor="#666666"> Wet Boiling Point

</td> <td align="center"> 284F

</td> <td align="center"> 311F

</td> <td align="center"> 356F

</td> </tr> </tbody></table>

The DOT 3 and DOT 4 specifications are for glycol based (regular) brake fluid, while DOT 5 is for silicone.

Silicone DOT 5 is not compatible with the ABS hydraulic control unit because it doesn't lubricate the ABS pump like glycol based fluid. Silicone is slightly more compressible than glycol fluid. It has a higher wet boiling point because it doesn't absorb moisture like glycol fluid. This lack of moisture absorption causes problems when water gets in the brake system. Instead of mixing with the brake fluid (so it can be flushed out easily), the moisture gets trapped at low points in the system and causes rust.


11,905 Posts
Discussion Starter #3
Stoptech stage 1 kit which includes:

Front and rear pads, SS lines and Motul RBF600 fluid was $202. The Brembo front rotors were $350.
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