Wonderboy Posted June 29, 2009 Report Share Posted June 29, 2009 So Im just curious if there are any potentially harmful differences between Dot 3 and Dot 4 brake fluid. I know the boiling point of the Dot 4 is higher and that is why I want to use it but, I have never gone from one to the other before. The reason Im wanting to know is because Ive got an issue with my clutch pedal getting kinda funky feeling but, only when the car is hot, like on longer trips or if Im running it really hard. When the car cools off its totally fine again. Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted June 29, 2009 Report Share Posted June 29, 2009 you can put 4 in 3, but not the other way around...suck all the 3 out of the clutch master with a vacula, then fill it up with 4 and bleed, fill it up again and bleed. Quote Link to comment Share on other sites More sharing options...
Wonderboy Posted June 29, 2009 Author Report Share Posted June 29, 2009 Is there any particular brand you would recommend? I do drive the shit out of this car and it does get awful hot at times so I need a fluid that can handle it. Quote Link to comment Share on other sites More sharing options...
Farkas Posted June 29, 2009 Report Share Posted June 29, 2009 you can put 4 in 3, but not the other way around... And why is that, rob? Quote Link to comment Share on other sites More sharing options...
AJ Posted June 29, 2009 Report Share Posted June 29, 2009 wilwood exp 600 plus racing brake fluid. jegs has it. Quote Link to comment Share on other sites More sharing options...
BIGGU Posted June 29, 2009 Report Share Posted June 29, 2009 ATE super blue is what im running in my SC. Quote Link to comment Share on other sites More sharing options...
Rob1647545496 Posted June 29, 2009 Report Share Posted June 29, 2009 http://www.seinesystems.com/BrakeFluids.htm i'm running Motul 600 i got 3 bottles for $55 from corollasport.com Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted June 29, 2009 Report Share Posted June 29, 2009 And why is that, rob? dot 4 has a higher boiling point.(wet and dry) and putting a lower boiling point fluid in a system that has a higher boiling fluid in it would be just bad IMO. even tho they will mix, i wouldnt step down. Here's more detail than you really want: DOT3 is an aliphatic polyether. DOT4 is borate ester based. DOT5 is polydimethylsiloxane (silicone based). DOT5.1 is borate ester based, thus its compatibility with DOT3 and DOT4. More information can be obtained from the following standards documents: DOT3: SAE J1703 DOT4: FMVSS 116; proposed SAE standard J1704 DOT5: SAE J1705 DOT5.1: No SAE spec DOT 3: This brake fluid is a poly glycol base product. Its dry boiling point (ERBP) is 205°C minimum and wet boiling point (Wet ERBP) is 140°C minimum. It absorbs 1 to 2 percent of water per year depending on climate and operating conditions. It is used in most domestic cars and light trucks in normal driving. This brake fluid does not require cleaning the system and can be mixed with DOT 4 and DOT 5.1 without damage the system. This brake fluid absorbs moisture from the atmosphere thus reduces its boiling point (ERBP). It can also damage the paint on a vehicle. DOT 4:This brake fluid is also based upon poly glycol. Its dry boiling point (ERBP) is 230°C minimum and wet boiling point (Wet ERBP) is 155°C minimum. It is used in medium and higher size of modern cars; and also for vehicles in high-altitude, towing, high-speed braking situations or ABS systems. This brake fluid does not require cleaning the system and it can be mixed with DOT 3,DOT 5.1 without damage to the system. This brake fluid also absorbs moisture out of the atmosphere thus reduces its boiling point (ERBP). It can also damage the paint on a vehicle. The modified poly glycol boric ester DOT4 brake fluid is also available. DOT 5: This brake fluid is based upon silicone. Its dry boiling point (ERBP) is 260°C minimum and wet boiling point is (Wet ERBP) 180°C. It is used in applications, like for weekend, antique, collector cars that sit for long periods and for some military vehicles. Some car manufacturers are also used in their road driven vehicles. This brake fluid does not mix with DOT 3, DOT 4 or DOT 5.1. It will not absorb water and will not damage the paint on a vehicle. It is also compatible with most rubber formulations. It absorbs more air and giving poor pedal feeling. It is unsuitable for racing due to more compressibility under high temperatures. If as little as one drop of water enters the fluid, severe localized corrosion, freezing or gassing may occur. This can happen because water is heavier and not mixable with silicone fluids thus it is unsuitable for ABS. DOT 5 fluid is highly compressible due to aeration and foaming under normal braking conditions, providing a spongy brake feel. Poly glycol type fluids are 2 times less compressible than silicone type fluids, even when heated. DOT 5.1: This brake fluid is also based upon poly glycol. Its dry boiling point (ERBP) is 260°C minimum and wet boiling point (Wet ERBP) is 180°C minimum. It is used in severe-duty vehicles such as fleets and delivery trucks; towing vehicles, and racecars. It can be mixed with DOT 3 or DOT 4 without damage to the system. It maintains higher boiling point than DOT 3 or DOT 4 fluids. It is excellent for severe duty applications particularly for racing of car. It also absorbs moisture out of the atmosphere and thus reduces its boiling point. It can also damage the paint on a vehicle. most all this info can be found here http://www.advancepetro.com/differentbrakefluid.htm and many other links all over the web. google is your friend Quote Link to comment Share on other sites More sharing options...
Cordell Posted June 29, 2009 Report Share Posted June 29, 2009 I was not aware of dot 5.1 so why not just use that? Quote Link to comment Share on other sites More sharing options...
Farkas Posted June 29, 2009 Report Share Posted June 29, 2009 dot 4 has a higher boiling point.(wet and dry) and putting a lower boiling point fluid in a system that has a higher boiling fluid in it would be just bad IMO. even tho they will mix, i wouldnt step down. Here's more detail than you really want: DOT3 is an aliphatic polyether. DOT4 is borate ester based. DOT5 is polydimethylsiloxane (silicone based). DOT5.1 is borate ester based, thus its compatibility with DOT3 and DOT4. More information can be obtained from the following standards documents: DOT3: SAE J1703 DOT4: FMVSS 116; proposed SAE standard J1704 DOT5: SAE J1705 DOT5.1: No SAE spec DOT 3: This brake fluid is a poly glycol base product. Its dry boiling point (ERBP) is 205°C minimum and wet boiling point (Wet ERBP) is 140°C minimum. It absorbs 1 to 2 percent of water per year depending on climate and operating conditions. It is used in most domestic cars and light trucks in normal driving. This brake fluid does not require cleaning the system and can be mixed with DOT 4 and DOT 5.1 without damage the system. This brake fluid absorbs moisture from the atmosphere thus reduces its boiling point (ERBP). It can also damage the paint on a vehicle. DOT 4:This brake fluid is also based upon poly glycol. Its dry boiling point (ERBP) is 230°C minimum and wet boiling point (Wet ERBP) is 155°C minimum. It is used in medium and higher size of modern cars; and also for vehicles in high-altitude, towing, high-speed braking situations or ABS systems. This brake fluid does not require cleaning the system and it can be mixed with DOT 3,DOT 5.1 without damage to the system. This brake fluid also absorbs moisture out of the atmosphere thus reduces its boiling point (ERBP). It can also damage the paint on a vehicle. The modified poly glycol boric ester DOT4 brake fluid is also available. DOT 5: This brake fluid is based upon silicone. Its dry boiling point (ERBP) is 260°C minimum and wet boiling point is (Wet ERBP) 180°C. It is used in applications, like for weekend, antique, collector cars that sit for long periods and for some military vehicles. Some car manufacturers are also used in their road driven vehicles. This brake fluid does not mix with DOT 3, DOT 4 or DOT 5.1. It will not absorb water and will not damage the paint on a vehicle. It is also compatible with most rubber formulations. It absorbs more air and giving poor pedal feeling. It is unsuitable for racing due to more compressibility under high temperatures. If as little as one drop of water enters the fluid, severe localized corrosion, freezing or gassing may occur. This can happen because water is heavier and not mixable with silicone fluids thus it is unsuitable for ABS. DOT 5 fluid is highly compressible due to aeration and foaming under normal braking conditions, providing a spongy brake feel. Poly glycol type fluids are 2 times less compressible than silicone type fluids, even when heated. DOT 5.1: This brake fluid is also based upon poly glycol. Its dry boiling point (ERBP) is 260°C minimum and wet boiling point (Wet ERBP) is 180°C minimum. It is used in severe-duty vehicles such as fleets and delivery trucks; towing vehicles, and racecars. It can be mixed with DOT 3 or DOT 4 without damage to the system. It maintains higher boiling point than DOT 3 or DOT 4 fluids. It is excellent for severe duty applications particularly for racing of car. It also absorbs moisture out of the atmosphere and thus reduces its boiling point. It can also damage the paint on a vehicle. most all this info can be found here http://www.advancepetro.com/differentbrakefluid.htm and many other links all over the web. google is your friend Oh, I already knew the answer.. but I wanted to see if you weren't just pulling something out of your ass Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted June 29, 2009 Report Share Posted June 29, 2009 Oh, I already knew the answer.. but I wanted to see if you weren't just pulling something out of your ass you know me i just play it by ear... Quote Link to comment Share on other sites More sharing options...
Guest Removed Posted June 29, 2009 Report Share Posted June 29, 2009 I was not aware of dot 5.1 so why not just use that? $$$$$ and harder to find etc. i think most of these racing fluids are 5.1 Quote Link to comment Share on other sites More sharing options...
Main3s Posted June 29, 2009 Report Share Posted June 29, 2009 So what do most of you run in your "race" cars? I'm about to upgrade the brake system on my car and was going to bleed out the master cylinder as well and replace the fluid. It’s no longer a street/ strip car, but I do drive a little spirited at times. After reading the above article I’m thinking about the DOT 4. I didn’t realize there was so much to break fluid. Quote Link to comment Share on other sites More sharing options...
Dave1647545494 Posted June 30, 2009 Report Share Posted June 30, 2009 unless your road racing or auto crossing or you pull a really big trailer just buy wahtever is on sale at the autoparts store and flush the fluid yearly and you'll have no problems with it Quote Link to comment Share on other sites More sharing options...
AJ Posted June 30, 2009 Report Share Posted June 30, 2009 i bleed the clutch when the fluid starts to change color. so about once a month to every other month depending on how many autocrosses and track days i go to. brakes i bleed every 2 autocrosses and before every track day. Quote Link to comment Share on other sites More sharing options...
Wonderboy Posted June 30, 2009 Author Report Share Posted June 30, 2009 Well thanks for the info and fluid recommendations guys. Im gonna look into some of those more "high end" fluids that were named. Quote Link to comment Share on other sites More sharing options...
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