Dot5?
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Dot5? Is anyone currently running Dot5 as their clutch fluid? It looks like the silicon based dot5 at the local autoshop has a 584 degree boiling point, quite a bit better then the 311 boiling point of the dot 4...thought it does warn on the bottle "Do not use with anti-lock braking systems" not sure what that is for.
So who's running it and for how long? I gotta bleed my clutch soon and want to use a much higher boiling point fluid if I can.
So who's running it and for how long? I gotta bleed my clutch soon and want to use a much higher boiling point fluid if I can.
I suggest using DOT 5.1 as this should conform to all your cars requirements and still provide great boiling resistence. In am a fan of the Motul RBF600. I do suggest that you make sure that whichever fluid you choose meets your system requirements. Let me know if you have any further questions. Thanks!
You DO NOT want to run DOT 5 in your system. Silicone based fluid is not compatible with the seals used in the systems for petroleum based DOT 3 & DOT 4 fluids. Now DOT 5.1 is supposed to be compatible. But the DOT 5 will eat your seals and cause problems.
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When you drilled it out what size bit did you use?
I've seen directions on a few different places but none of them mention the right bit size. I was planning on whatever was slightly larger then the size that would fit. *shrugs*
I've seen directions on a few different places but none of them mention the right bit size. I was planning on whatever was slightly larger then the size that would fit. *shrugs*
I can't remember. Whatever I found in the write-up. Don't want to go too big because you don't want to damage the rubber hose. Just want to remove the metal restriction in the end fitting.
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Nobody is running any of these high performance dot 5.1 fluids though? Was hoping for some personal experience.
TIA
-Cthulu
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I'd love to find some of this high boiling point brake fluids locally so I can test it out. I've found that after some long driving, DOT 4 degrades quite a bit being cooked inside by the engine and clutch heat. Ie 4-5 hour drive then WOT runs will usually give me a sticking clutch on the 4th gear redline to 5th gear shift... not that I test out these crazy situations on a regular basis heh
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As for brake fluid, DOT 3 and 4 are NOT petroleum based as was mentioned. They are a polyglycol fluid, all of which are amber or clear in color. It will not damage the rubber parts of the system or cause the seals to swell as a petroleum based fluid would. DOT 4 has a wet boiling point of 311 degrees F, while DOT 3 is only 284 degrees, making DOT 4 the obvious choice for any application. Both absorb moisture, however, unlike DOT 5.
Basically DOT 5 is a silicone based brake fluid, so unlike DOT 3 and DOT 4, it will not absorb moisture from the system or from the air. It will, however, hold air much more so than DOT 3/4 will, so bleeding the system of all trapped air can be a challenge. The reason DOT 5 can't be used in ABS systems is because it airates easily, so the ABS pump would basically cause trapped air bubbles in the system. DOT 5 is purple in color, and is not compatible with DOT 3,4, or 5.1. However, like DOT 3/4, it will not harm the rubber seals in the system.
The best option available is DOT 5.1. Its a non-silicone based fluid and clear/amber in color like DOT3/4. Its also compatible with DOT 3/4, so flushing the system completely is not required. It has a wet boiling point of 356, higher than both DOT 3 and 4, and equivelent to that of DOT 5.
Hope that clears some things up.
I did, however, find some high performance fluid made by Brembo, with a wet boiling point of 399 degrees F, and its fully compatible with DOT 3, 4, and 5.1:
http://www.brembo.com/ENG/Racing-Bra...rake+Fluid.htm
Wilwood makes a similar fluid, with a dry boiling point of 570 degrees (doesn't list wet boiling point):
http://www.wilwood.com/Products/006-...-EXP/index.asp
Last edited by Wesmanw02; Sep 29, 2008 at 04:42 PM.
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I did, however, find some high performance fluid made by Brembo, with a wet boiling point of 399 degrees F, and its fully compatible with DOT 3, 4, and 5.1:
http://www.brembo.com/ENG/Racing-Bra...rake+Fluid.htm
[/url]
http://www.brembo.com/ENG/Racing-Bra...rake+Fluid.htm
[/url]
"Brembo LCF 600 plus must not be used in Brake Systems containing magnesium parts."
Don't suppose anyone knows if we have magnesium in our clutch systems?
Bad information.
Castrol SRF is NOT DOT 5. If you are reading around on different sites that sell it, they recommend not mixing it with other fluids because it will degrade the dry/wet boiling points to the point of not being worth the money.
I've been running SRF for the better part of the past year in my clutch hydraulics, and it flat out works. The frrax.com guys use it for their brakes all the time...they'd probably have tons of problems if it was a DOT 5, wouldn't they? Yet they don't, because it isn't a DOT 5 fluid. It is DOT 4 (the bottle specifically states "exceeds DOT 4 specifications).
Castrol SRF is NOT DOT 5. If you are reading around on different sites that sell it, they recommend not mixing it with other fluids because it will degrade the dry/wet boiling points to the point of not being worth the money.
I've been running SRF for the better part of the past year in my clutch hydraulics, and it flat out works. The frrax.com guys use it for their brakes all the time...they'd probably have tons of problems if it was a DOT 5, wouldn't they? Yet they don't, because it isn't a DOT 5 fluid. It is DOT 4 (the bottle specifically states "exceeds DOT 4 specifications).
Right or wrong I've got DOT5 in mine right now. Purple stuff. I was breaking down the 5.1, so we tried something else, and did a full flush. I'll let you know if purple stuff starts leaking out! 
Bad information.
Castrol SRF is NOT DOT 5. If you are reading around on different sites that sell it, they recommend not mixing it with other fluids because it will degrade the dry/wet boiling points to the point of not being worth the money.
I've been running SRF for the better part of the past year in my clutch hydraulics, and it flat out works. The frrax.com guys use it for their brakes all the time...they'd probably have tons of problems if it was a DOT 5, wouldn't they? Yet they don't, because it isn't a DOT 5 fluid. It is DOT 4 (the bottle specifically states "exceeds DOT 4 specifications).
Castrol SRF is NOT DOT 5. If you are reading around on different sites that sell it, they recommend not mixing it with other fluids because it will degrade the dry/wet boiling points to the point of not being worth the money.
I've been running SRF for the better part of the past year in my clutch hydraulics, and it flat out works. The frrax.com guys use it for their brakes all the time...they'd probably have tons of problems if it was a DOT 5, wouldn't they? Yet they don't, because it isn't a DOT 5 fluid. It is DOT 4 (the bottle specifically states "exceeds DOT 4 specifications).
http://www.raceshopper.com/castrol_s...ke_fluid.shtml
Apparently they must have their info and specs wrong.
This site seems to say you are talking about, compatible with DOT 3/4:
http://www.hrpworld.com/index.cfm?fo...ction=category