Lucas Dot 3 vs Dot 4??

[Xeno]

I've been researching brake fluids and I came across Lucas. What I don't understand is how their Dot 3 has a higher dry and wet boiling point than 4. What am I missing?

Dot 4

Dot 3

 

[901Memphis]

The DOT 4 is just lower viscosity. I am not a big fan of Lucas products, i would look elsewhere if i wanted a high quality brake fluid. I am sure the Lucas is fine for regular stuff though, but you can do better.

Brembo Sport Evo 500 is 520F
http://www.tirerack.com/brakes/brakes.js...;cat=BrakeFluid



Amsoil is 520F/580F for DOT3/DOT4
http://www.amsoil.com/shop/by-product/ot.../?code=BF4SN-EA



ATE Type 200 is 536F
http://www.ate-na.com/www/ate_us_en/themes/20_ate_brake_products/brake_fluid/bf_info_us.html

I found this chart pretty handy too. You can sort by boiling point and other things

https://www.lelandwest.com/brake-fluid-comparison-chart.cfm?startRow=1&SF=6&ST=1

 

[Greasymechtech]

Both Lucas fluids exceed DOT requirements.

I find the boiling point meaningless for a daily driver.

As long as the fluids meets the OE requirements, use it.

Bleeding regularly every year or two is more important.

If you boil your brake fluid, you need to figure out why and modify to solve the brake overheating problem.

 

[slacktide_bitog]

Not a fan of Lucas.

I'd rather use one of these:
Wagner Severe Duty DOT 5.1
Castrol LMA
Valvoline DOT 3/4
Pentosin DOT 4 LV

But any DOT 3 or 4 will work fine as long as you flush it regularly. That is much more important than what fluid you use. Even cheap Walmart DOT 3 is fine if you change it ever 2-3 years (like you;re supposed to with any brake fluid, even the expensive stuff)