BRAKE FLUID
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Originally Posted By: jake88
Originally Posted By: MolaKule
Maybe, but let's not leave the impression you can mix DOT 5.0 and 5.1 fluids; they are not compatible.
Bolded for emphasis
I would go one further. Never, ever, use DOT 5 unless your Owner's Manual specifically calls for it, or unless you are very (extra emphasis on very) experienced with brake systems and know exactly how to change over to silicone brake fluid.
Originally Posted By: MolaKule
Maybe, but let's not leave the impression you can mix DOT 5.0 and 5.1 fluids; they are not compatible.
Bolded for emphasis
I would go one further. Never, ever, use DOT 5 unless your Owner's Manual specifically calls for it, or unless you are very (extra emphasis on very) experienced with brake systems and know exactly how to change over to silicone brake fluid.
The higher boiling points of DOT 4 and 5.1 are useful if you do hard driving or in severe conditions.
But it really doesn't matter as long as you change it every 2-3 years which you're supposed to do anyway regardless of brake fluid choice. Regular fluid changes are MUCH more important than what fluid you actually use. Even cheap Walmart DOT 3 is fine if you flush every 2-3 years, or when you replace your pads/rotors.
Notice it's just 2-3 years and NOT dependent on mileage. That is because the brake fluid constantly absorbs moisture in a way that doesn't matter how much the car is driven. Whether you're in stop-and-go traffic, on the highway, on the track, or when the car is parked, the fluid is absorbing moisture.
High performance brake fluid still has to be changed every 2-3 years. Even though the dry and wet boiling points are higher, some of them absorb moisture at a faster rate, Moisture does more than lower the boiling point: it also introduces corrosion into the system. So even if the wet boiling point is high, and can stay high for a long time, leaving it in there for 10 years is bad.
The wet BP means that at 3.7% moisture. However, the time it takes to get 3.7% moisture may vary, and something like RT700 could possibly reach 3.7% in only a few months/less than a year! In contrast, your average Prestone fluid might take 2 years to get 3.7% water. (Those time frames are totally made up, and I have no idea how long it would actually take for each fluid to reach the wet BP)
You can probably get away with changing the fluid whenever you replace the pads and rotors though.
Castrol's brake fluid is said to absorb moisture at a slower rate, but I'd still change it at the same interval.
But it really doesn't matter as long as you change it every 2-3 years which you're supposed to do anyway regardless of brake fluid choice. Regular fluid changes are MUCH more important than what fluid you actually use. Even cheap Walmart DOT 3 is fine if you flush every 2-3 years, or when you replace your pads/rotors.
Notice it's just 2-3 years and NOT dependent on mileage. That is because the brake fluid constantly absorbs moisture in a way that doesn't matter how much the car is driven. Whether you're in stop-and-go traffic, on the highway, on the track, or when the car is parked, the fluid is absorbing moisture.
High performance brake fluid still has to be changed every 2-3 years. Even though the dry and wet boiling points are higher, some of them absorb moisture at a faster rate, Moisture does more than lower the boiling point: it also introduces corrosion into the system. So even if the wet boiling point is high, and can stay high for a long time, leaving it in there for 10 years is bad.
The wet BP means that at 3.7% moisture. However, the time it takes to get 3.7% moisture may vary, and something like RT700 could possibly reach 3.7% in only a few months/less than a year! In contrast, your average Prestone fluid might take 2 years to get 3.7% water. (Those time frames are totally made up, and I have no idea how long it would actually take for each fluid to reach the wet BP)
You can probably get away with changing the fluid whenever you replace the pads and rotors though.
Castrol's brake fluid is said to absorb moisture at a slower rate, but I'd still change it at the same interval.
Originally Posted By: tommygunn
Castrol's brake fluid is said to absorb moisture at a slower rate, but I'd still change it at the same interval.
Their DOT 4 Advance stuff (formerly called GT LMA) at least might.
MANY on here have warned me that their React SRF Racing fluid WILL absorb moisture at a VERY quick rate (as you have stated for other racing type fluids above), despite it having the highest in the world by a good measure, WET boiling point.
Castrol's brake fluid is said to absorb moisture at a slower rate, but I'd still change it at the same interval.
Their DOT 4 Advance stuff (formerly called GT LMA) at least might.
MANY on here have warned me that their React SRF Racing fluid WILL absorb moisture at a VERY quick rate (as you have stated for other racing type fluids above), despite it having the highest in the world by a good measure, WET boiling point.
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