DOT 4 the right brake fluid???

[Old N' Grumpy]

2014 Roadster...is DOT 4 what I want or DOT5.1 ???

 

[Mighty Mouse]

Hey Grumpy it's good to hear from you. I used DOT 4 in my 14 Rocket so unless something has changed I would say 4. Cheers.

 

[Old N' Grumpy]

Hey Grumpy it's good to hear from you. I used DOT 4 in my 14 Rocket so unless something has changed I would say 4. Cheers.

Likewise! Onward ho with the DOT 4 then. Thanks bud!

 

[Mongler07]

All brake fluid is the same with the exception of dot 5 because it is a silicone fluid.
Use whatever you like.
The difference is in a nut shell that the higher the dot # the higher the "quality" so use dot 4 or 5.1 or 3 or whatever you like. Adding any number to any different number does not do anything bad.
Now if you want to understand brake fluid the basic idea for the sake of a short post is that the higher the dot# the higher the boiling point is but this comes at a cost trade off of service to keep that wet boiling point.
Basically dot 3 will last a long time but it's quick to fade out vs 5.1.
Just 5% water in the system will turn the wet boiling point in half. It's a small system so just a tiny bit spoils the system. It's been proven that aluminum and cast iron brake calipers will leach moisture into the brake system due to the vapor intrusion during heat cycles.
If you want to have the highest dry boiling point then you trade off service. Basically some of not most 5.1s require fluid change every 6 months.
Just slap some motul 5.1 in there and change it once a year. This stuff is cheap and the highest performer on the market with the longest life.

 

[Old N' Grumpy]

All brake fluid is the same with the exception of dot 5 because it is a silicone fluid.
Use whatever you like.
The difference is in a nut shell that the higher the dot # the higher the "quality" so use dot 4 or 5.1 or 3 or whatever you like. Adding any number to any different number does not do anything bad.
Now if you want to understand brake fluid the basic idea for the sake of a short post is that the higher the dot# the higher the boiling point is but this comes at a cost trade off of service to keep that wet boiling point.
Basically dot 3 will last a long time but it's quick to fade out vs 5.1.
Just 5% water in the system will turn the wet boiling point in half. It's a small system so just a tiny bit spoils the system. It's been proven that aluminum and cast iron brake calipers will leach moisture into the brake system due to the vapor intrusion during heat cycles.
If you want to have the highest dry boiling point then you trade off service. Basically some of not most 5.1s require fluid change every 6 months.
Just slap some motul 5.1 in there and change it once a year. This stuff is cheap and the highest performer on the market with the longest life.

Thank you for the education Sir! I know a little more today.

 

[Gregger]

All brake fluid is the same with the exception of dot 5 because it is a silicone fluid.
Use whatever you like.
The difference is in a nut shell that the higher the dot # the higher the "quality" so use dot 4 or 5.1 or 3 or whatever you like. Adding any number to any different number does not do anything bad.
Now if you want to understand brake fluid the basic idea for the sake of a short post is that the higher the dot# the higher the boiling point is but this comes at a cost trade off of service to keep that wet boiling point.
Basically dot 3 will last a long time but it's quick to fade out vs 5.1.
Just 5% water in the system will turn the wet boiling point in half. It's a small system so just a tiny bit spoils the system. It's been proven that aluminum and cast iron brake calipers will leach moisture into the brake system due to the vapor intrusion during heat cycles.
If you want to have the highest dry boiling point then you trade off service. Basically some of not most 5.1s require fluid change every 6 months.
Just slap some motul 5.1 in there and change it once a year. This stuff is cheap and the highest performer on the market with the longest life.

in short.... +1

 

[Mongler07]

Thank you for the education Sir! I know a little more today.

I have a bad habit of going down every rabbit hole I find. Once I got into serious motorsports and got into groups of professionals I found most of the "knowledge" out there is B's but good enough. The crew I do some work with changes brake fluid after every event due to heat cycles.

 

[TURBO200R4]

you could move to arizona with 3% humdity most of the time

 

[Mongler07]

you could move to arizona with 3% humdity most of the time

Bro at least it's in the 15 to 20. Typical is about 40 +/- a few.
Colorado. Inside a air conditioned space in gun safe with a heater dryer. My deaicant beads are spent after about 5 days.
Contrary to popular myth, ambient humidity does not mean there is no water in the air. Ever run an air compressor for just a dozen cycles out in the desert.... Water still condensed in the tank.
When it comes to brake fluid, it is in a closed system. The little bit that does make it into the system is more than enough.

 

[Old N' Grumpy]

How ya doing Herman??? Long time since I been on here. Missed your sense of humor and funny retorts!