LegendsRacer - Legends & Bandolero Racing Forum
LEGENDS => Brakes => Topic started by: Tom Cole on April 21, 2007, 09:44:57 am
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You can skip reading all this and just go buy some Wilwood EXP 600 Racing Brake Fluid. The only thing better is from Castrol and it is VERY expensive and is beyond our needs. Wilwood also makes 570 Racing Brake Fluid which costs half as much as EXP but has a slightly lower boiling point.
Also, NEVER use a silicone (DOT 5) brake fluid. It does not absorb water, so when water drops get into your system, and they will, they will boil at 210° causing vapor lock which will either lock-up your brakes or cause brake failure. DOT 5 also has a tendency to foam easily giving you a squishy pedal.
Brake fluid has two boiling points. The Dry boiling point is the temperature where the fluid boils when it is fresh out of the sealed bottle. Wilwood EXP has a 626° dry boiling point. Most standard DOT3 fluid has a dry boiling point of 400°. Heavy Duty DOT3 or 4 usually has a 470° dry boiling point. The higher this boiling point, the more use your brakes can stand before they will start to fade or fail.
The second boiling point for brake fluid is its' wet boiling point. This is the temperature where the fluid boils when it is saturated with water. Most DOT 3 fluid has a wet boiling point of 278° and Wilwood EXP has a wet boiling point of 417°. One of the jobs of brake fluid is to absorb water from the brake system. For lack of a more scientific explanation, let's just say that by absorbing the water, the brake fluid gives up some of its' dry boiling point peak temp, in order to keep the water in the system from boiling.
Boiling is bad. Provided your master cylinder, calipers, and slave cylinders are in good working order, if you come in from a run and your front brakes are so locked-up that you can't turn the wheels with your hands, then you are probably boiling your fluid and either bleeding the brakes will be necessary, or a complete change of brake fluid will be necessary. You should bleed your brakes about every two weeks.
I'll explain how to do that later.
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We found a good DOT 4 fluid at NAPA that was a lot less expensive and is doing a great job. It is their Premium DOT4 and has a wet boiling point of 311°. It doesn't list the dry boiling point, but 311° is pretty good, especially if you bleed your brakes every 2-3 weeks or so.
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I agree with admin. wilwood 570 goes in any car that I work on. Dot 3 is good for a street application, but they make racing brake fluid for a reason.
Brad
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Hey, how much would it take to flush out an entire braking system on a legends car, mine needs it bad? also would i follow any different rule from just bleeding the brakes to FLUSHING the brakes?
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Good post Tom!
I've used the stuff from NAPA; NO Problems.
Also, have used the Wilwood 570. Again, No Problems.
LR24,
I have totally drained and flushed my brake system every season. When they sit for any length of time, moisture tends to sneak in there. Not a good thing! I drain every bit of fluid, blow out the lines, rebuild the master and brake cylinders, and started with everything fresh. It is the off season after all. Clearing all the lines and rebuilding now; is the time to do it. Wait 'til right before the season starts to refill and bleed.
JMHO
Steve
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Just an FYI...Fast96 is my son Trey. We are using the NAPA stuff. It has worked just fine.
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napa 5.1 works well for us non silicone but its a little expensive vs napa dot 4. just my 2 cents and boiling point around 400 plus degrees.
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Do any of yall use Motul 600?
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Motul 600 is just fine and you will have no problem!
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Just remember when buying any brake fluid to check the wet boiling point.
99.9% of the time there will be some contaminants in the brake system, rendering the dry number inaccurate.