Brake fluid

[shooter3001]

What is the difference between DOT3 and DOT4 brake fluid? I want to change the clutch fluid on my wifes 99 RSTD, and I have an almost full bottle of DOT3 in the garage. Can I use it instead of DOT4?

[Snarley Bill]

basically the same dot 4 has a higher temp rating . dot 3 will be fine for you brakes or clutch.

[utadventure]

Dry DBoiling Point Wet Boiling Point Dry Boiling Point Wet Boiling Point

DOT 3 401ºF 284º F

DOT 4 446º F 311º F

DOT 5 500º F 356º F

DOT 5.1 518º F 375º F

 

It appears from the information above that is mostly is a diffence in when the brake fluid would break down and boil. (Wet Point refers to 3% of the volumne in the system is water)

[pegscraper]

The boiling point of the fluid is all it (ahem) boils down too. Dot 4 will be higher.

[GigaWhiskey]

I have understood that if you have a DOT 3 brake system, you can use DOT 3 and DOT 4. If you want to use DOT 5, you must replace o-rings and seals to meet the DOT 5 specification. So, sounds like you want to stay away from DOT 5 unless you got the time and money.

[lonestarmedic]

I believe DOT 5 is silicone based fluid. High temp rating and better moisture resistance. However not compatible with DOT 3 and 4 rubber goods.

 

JB

[Yammer Dan]

You can boil DOT 3 if you run The Dragon a little hard. Ask Skid. 4 might be the best if you have a 1st Gen.

 

2nd Gen owners could probally use 3 without any problems.

[Squeeze]

Using fresh DOT 3 in the Clutch Line may not give any Problems.

 

 

 

Other than this, refer to Yammer Dan's Statement. :rotf::rotf:

[shooter3001]

Thanks for the info guys. I'm going to use the DOT 3. The wife isn't that aggressive of a rider so it should do fine.

[Squidley]

I believe DOT 5 is silicone based fluid. High temp rating and better moisture resistance. However not compatible with DOT 3 and 4 rubber goods.

 

JB

 

 

We have a winner! DOT 3 & 4 Ok together, DOT 5 no good for us