Stopping/Braking Distance Using Contaminated Brake Fluid

[Nihonsun]

I have been doing some research on contaminated brake fluid and have problem to obtain the information of stopping/braking distance while the vehicle's brake fluid is contaminated.

Example:
If a vehicle is tested with 2% of moisture from the brake reservoir, what is the stopping/braking distance when the brake pedal is applied?

And how about different % of moisture when the brake pedal is applied?

[g-m]

I forsee you doing a lot of brake fluid flushes and refills

[BlackArcher101]

I'm guessing it would have a negligible effect on stopping distance and power. It's still an incompressible fluid so I dno't see the hydraulic force being weaker. Someone correct me if I'm wrong. Air is a different story though.

The problem comes with corrosion of seals and hardware.

[alloroc]

Originally posted by BlackArcher101
I'm guessing it would have a negligible effect on stopping distance and power. It's still an incompressible fluid so I dno't see the hydraulic force being weaker. Someone correct me if I'm wrong. Air is a different story though.

The problem comes with corrosion of seals and hardware.


Water can be a problem when the brakes get hot and it boils out of the fluid.

Track days, long down hills, trailer towing etc.

Normal day to day you don't notice - and that is why it can be so dangerous - when you do need that long hard stop suddenly it isn't there.

[BlackArcher101]

What exactly happens when it boils out... where does it go? And how does it give you no brakes?

[420Ninja]

What?

I can gaurentee you that most vehicles out there are running on the original brake fluid. Either way if you drive the snot out of your car and there are cases when those extra 6 feet are going to be nessicary then sure do a flush every couple years, but really i dont see the reason why a daily driven car would need to be held to such high standards, and this is assuming that that much moisture will get into the braking system. And then assuming the fluid makes it far enough into the system where it will have a actual effect.

Although to play devils advocate, if the manufacture suggests it then you never know, there might actually be a good reason why.

[H4LFY2nR]

Originally posted by BlackArcher101
What exactly happens when it boils out... where does it go? And how does it give you no brakes?

When the water boils out it would become a gas (steam) and would therefore be compressible. Any extra force on the brake pedal would not raise the line pressure in the brakes and only be used to compress the gas. So you wouldn't be able to apply any more braking power until you have compressed the steam back into liquid water.

[GTS Jeff]

Originally posted by 420Ninja
What?

I can gaurentee you that most vehicles out there are running on the original brake fluid. Either way if you drive the snot out of your car and there are cases when those extra 6 feet are going to be nessicary then sure do a flush every couple years, but really i dont see the reason why a daily driven car would need to be held to such high standards, and this is assuming that that much moisture will get into the braking system. And then assuming the fluid makes it far enough into the system where it will have a actual effect.

Although to play devils advocate, if the manufacture suggests it then you never know, there might actually be a good reason why. 1. You can make no such gaurantee.
2. Moisture leaks into the brake hydraulic system quite easily, which is why a glycol based brake fluid is used in the first place. Rubber seals and hoses let in moisture over time. Also, because the fluid absorbs water, it creates a gradient which continues to draw more moisture into the system.
3. As a hydraulic system, it doesn't matter where the moisture is, it will cause shit as pressure rises in the entire system when the pedal is pressed.
4. Being on the road with other cars whizzing around, pedestrians, and unexpected obstacles, I'd say it's pretty reasonable to hold your car's brakes a high standard of safety, wouldn't you? :dunno:

[carreckless]

I don't know exactly what is the distance to break on the given situation but I think it depends if the car is in a uphill or downhill. And using contaminated brake fluid means less brake power, please correct me if I'm wrong