Anyone try DOT 4 Synthetic Brake Fluid? (Page 3/4)
Frenchrafe OCT 19, 05:43 AM
Hi everyone,
Just my experience:
I've been using DOT 5 (silicon) brake fluid in my car for years. On and off the track!
Never had any problems or seals failing.

Regards,
Rafe

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"Turbo Slug" - '87 Fiero GT. 3800 turbo. Sticky tyres. Driven hard!
https://www.youtube.com/cha...1wZvWQlkYxTjivW_0XNg

theogre OCT 20, 12:34 AM

quote
Originally posted by Frenchrafe:
Hi everyone,
Just my experience:
I've been using DOT 5 (silicon) brake fluid in my car for years. On and off the track!
Never had any problems or seals failing.

You just got lucky.
Because very likely have pools of very wet DOT 3 4 or 5.1 or even Water migrate to any low areas and if is in calipers or drum slaves this can boil very easy w/o warning and have little or no brakes.
Frenchrafe OCT 20, 07:08 AM
Thanks Ogre. Ever the optimist😉
Next time I end up in the gravel at the end of the long straight, I'll be thinking of what you said 👍😁

No seriously, my entire brake system is replaced with new lines and calipers. It has never seen any other fluid but DOT5.
Before I upgraded the rear calipers, I managed to get the old pads glowing red at one race! The friction material was crumbling off the backing plate.
The pedal was always there, no fluid boiling, just severe pad and disc overheat.
DOT5 works in my case is all I'm saying.

Regards,
Rafe

------------------
"Turbo Slug" - '87 Fiero GT. 3800 turbo. Sticky tyres. Driven hard!
https://www.youtube.com/cha...1wZvWQlkYxTjivW_0XNg

La fiera OCT 20, 08:16 AM

GTIN Code: 889545069518
Liquid Measurement: 16.9 fl. oz.
Brake Fluid Type: DOT 4
Sold in Quantity: Each
Notes: Dry Boiling Point: 626 F. Wet Boiling Point: 417 F.
Dry Boiling Point: 626 °F
Wet Boiling Point: 417 °F

This is the fluid I use on my Fiero, Abarth (which I track 3 to 6 days a year) and my kart and NEVER had the brakes fade.
I personally don't bother with DOT5 fluids. It's more expensive and it can't mix it with DOT3 or 4 in case of an emergency.
Whether you run 3, 4 or 5 and you track your car more than twice a year or drive it spirited, it's good practice to flush your system with fresh
fluid yearly.
theogre OCT 20, 12:01 PM

quote
Originally posted by Frenchrafe:
Thanks Ogre. Ever the optimist😉
Next time I end up in the gravel at the end of the long straight, I'll be thinking of what you said 👍😁

No seriously, my entire brake system is replaced with new lines and calipers. It has never seen any other fluid but DOT5.
Before I upgraded the rear calipers, I managed to get the old pads glowing red at one race! The friction material was crumbling off the backing plate.
The pedal was always there, no fluid boiling, just severe pad and disc overheat.
DOT5 works in my case is all I'm saying.

Replace everything is maybe the Only time using 5 is "OK."
Most try to "flush" old parts and causes problems said above because Silicone Does Not mix w/ others and allows them to sink and stay wherever and often get wetter and wetter too.
theogre OCT 20, 12:06 PM

quote
Originally posted by La fiera:
This is the fluid I use on my Fiero, Abarth (which I track 3 to 6 days a year) and my kart and NEVER had the brakes fade.
I personally don't bother with DOT5 fluids. It's more expensive and it can't mix it with DOT3 or 4 in case of an emergency.
Whether you run 3, 4 or 5 and you track your car more than twice a year or drive it spirited, it's good practice to flush your system with fresh
fluid yearly.

Don't you mean can mix?

[This message has been edited by theogre (edited 10-20-2020).]

La fiera OCT 20, 01:21 PM

quote
Originally posted by theogre:


Don't you mean can mix?[/QUOTE]
I meant 5 won't mix with 3 or 4.
Blacktree OCT 20, 01:24 PM
^^

Edit: Rei beat me to it.

Side Note: I'll have to look up that Wilwood EXP stuff. Because my BMW might benefit from it.

[This message has been edited by Blacktree (edited 10-20-2020).]

theogre OCT 20, 01:51 PM

quote
Originally posted by La fiera:
I meant 5 won't mix with 3 or 4.

Ok and correct.

Bit confuse because Wilwood anything is more expensive too. $21.47 for 16.5 oz at Wilwood vs Valvoline and others DOT 4 ~ $8 per Quart (32 oz.)

Also
Brake Fade has little to nothing to do w/ Fluid used.
Fade is caused by overheated pad/shoes etc. and most times won't cause low pedal. Might feel spongy or not during fade problems. With "cheap" pads/shoes often is easy to have this w/o glowing rotors etc.

Fluid Boil will produce instant "Air"(steam) in the hydro and will causes low/spongy pedal and often won't work right again until you bleed them at minimum.
Boil fluid is trash and likely have fix other brake problems too.
Blacktree OCT 20, 02:10 PM

quote
Originally posted by theogre:

Bit confuse because Wilwood anything is more expensive too. $21.47 for 16.5 oz at Wilwood vs Valvoline and others DOT 4 ~ $8 per Quart (32 oz.)


The boiling point is much higher than generic DOT4 fluid.

According to FMVSS116 standards, DOT4 brake fluid must have a minimum dry boiling point of 230°C and a minimum wet boiling point of 155°C. The Wilwood fluid has (advertised) boiling points of 330°C and 214°C, respectively. That is significantly higher! For someone who does road racing, that will be worth the expense.