Brake fluid

[Dennis Kelley]

What brake fluid comes stock with the BDR? I have to add some fluid and don't know if its DOT 3, 4, 5?

[427sharpe]

I doubt very seriously they use DOT5, as it is not reccommended for compatability issues with most automotive master cylinder mfg.s such as Tilton. If I were you I would use DOT 4. Higher boiling point, better refining standards and it is compatible with DOT 3. If your system has 3 in it, 4 will mix fine but you will lose some of the benefits of DOT4. DOT5 is NOT compatible with either of the other 2!

[Dennis Kelley]

Thanks for the info. I'll stick some four in it.

[capfel]

Bob,

What year was your Everett-Morrison finished. Good to see that I'm not the only one.

Mine's a 1992 finished in 1995.

Chuck

[Dennis Kelley]

According to the person I spoke with in fla. at BDR its DOT 5. Does anyone know for sure or do I just gamble on f@@@@@g it up with the wrong fulid. BMW boards say Dot 4 ?????????????? I agree with 427 DOT 4 but I didn't fill it to begin with. Who knows

later Dennis

[oncebitten]

That would be synthetic DOT 5. Do not mix the types..

[tfarhood]

Does Backdraft also use Dot 5 in the clutch???

[bdr195]

I called Backdraft in Florida last week about this. The guy who answered (not Reg) said they use DOT 5 brake fluid and DOT4 for the clutch.

[Excaliber]

Dot 5 in the brakes? Thats silicone fluid. Which is great for "show cars" because it doesn't "eat paint" the way DOT 4 and the others do.

BUTT, no way, not a chance, under no circumstances, forget about it, I wouldn't go NEAR A RACE TRACK with DOT 5 Silicone fluid in my brakes. I'm just blown away BDR uses it for ANY application with their cars.

[Excaliber]

This quoted from the Wilwood web site:
"Wilwood does not recommend using DOT 5 fluid in any racing applications. DOT 5 fluid is not hygroscopic, so as moisture enters the system, it is not absorbed by the fluid, and results in beads of moisture moving through the brake line, collecting in the calipers. It is not uncommon to have caliper temperatures exceed 200° F, and at 212° F, this collected moisture will boil causing vapor lock and system failure. Additionally, DOT 5 fluid is highly compressible due to aeration and foaming under normal braking conditions, providing a spongy brake feel. DOT 5 fluid is best suited for show car applications where its anti-corrosion and paint friendly characteristics are important."

From Club Cobra:
Silicone brake fluid is very popular with vintage Corvette owners because it does not harm paint and does not absorb water, which could damage valuable original equipment brake system parts. It is also useful for cars in collections which are not driven. It is not recommended for much else.

From Club Cranky racing:
Question was, what do YOU guys use for brake fluid?
Castrol brake fluid like the pro's use costs $75.00 a qt.
Most of us part time wannabe racers use Wilwood Hitemp brake fluid or SS Brakes Hitemp fluid. Their are others not as expensive as the Castrol at around $7.00 a pt.


From the internet:
Boiling point of various brake fluids:
BRAND - wet boil - dry boil - dot

Castrol LMA.....311/446 dot 4
PFC z-rated.....284/550 dot 3
Wilwood 570...284/570 dot 3
AP-551............284/540 dot 3
AP-600............284/572 dot 3
and the liquid gold of brake fluid...
Castrol SRF.....518/590 dot 4

From the "TheBrakeman.Com" web site:
Brake Man577 Our fluid has been specially designed to meet the extreme conditions found in professional competition. With a dry boiling point of 577 degrees, and a wet boiling point of 300 degrees, it beats the competition cold, but does it for a third of the cost of the others. In order to buy a better fluid, you will spend over $25.00 a quart. Remember, what you purchase should match the job. Our brake fluid does just that by offering high temperature resistance, with the quality necessary to make sure that it lasts a long time! It is packaged in 12 oz bottles to keep it fresh and is economical so that you can "freshen the brake system as we recommend, before every race, for best results."
From the book "Engineer to Win", page 189:
"...the silicone brake fluids have made progress since "PREPARE TO WIN" (the book). Some of them are now almost useable in racing cars - but not quite. They still have high frequency vibration frothing problems and they are still compressible at high temperatures, which it is why it takes a few laps for the pedal to get spongy when gullible people try to use silicones to race with. We replace all our brake fluid long before it has a chance to collect moisture so I have never understood why anyone would spend money for the silicone ones anyway."

One more IMPORTANT point.
DOT5 will mix with DOT4 and cause the seals to swell up in caliper pistons, master cylinder and related "rubber" parts of your brake system.

[Cashburn]

BDR uses DOT5 Synth .. NOT organic. That's why it's "purple" when it shows up.

[Cashburn]

As for "Excaliber" post, I'm not sure if that was in jest... but it was funny.





Yeah 60's tech was for performance, todays' is for "show"...

[Art Burtt]

Can DOT 5 be replaced with out using all new brake seal etc.?

[CobraEd]

Take a little out and see if it mixes with water or if it globs up. If it globs up, then it is silicone based DOT 5. If it mixes right in with the water it is not DOT 5.


Ed

[Dennis Kelley]

Cashburn thank for the info. I just bleed them and the color was purple. I just didn't want to put the wrong stuff in it thanks again.
Synthdot5

later Dennis

[Nor Cal Al]

What does Tony Martin at the factory have to say? I am pretty sure this is not covered in the manual...but it should have been!

[uncltodd]

Manual? What manual?

I was never even offered a manual.

But I only spent $43K for #139.

And I have no idea where my $1K vinyl top is.

Hint.

UT

[BUCKEYE COBRA]

Is all DOT 5 purple? I have a earlier model BDR. My fluid is clear and does not mix with water. My cap states to use DOT 3 (does this mean anything?).
Thanks,
John

[Excaliber]

I have seen only clear silicone brake fluid, perhaps some specific brand is purple. A lot of master cylinders use the industry standard "Use DOT 3" type of imprint on their parts. That does NOT apply if the system is all ready filled with DOT 5. Don't mix 5 with anything else.

[round_midnight]

If I want to replace my fluid with DOT 4, are there any special procedures? Can I just do it the same way I would do an ordinary fluid change?