Hate to ask but.......I did some research on here yesterday from work so I could stop and get brake fluid for my bike and from what I understood my 2004 Road King Custom should use DOT 5. I got home and looked on the front cylinder cap and it says DOT 4, bike has stock brakes. So what is it? My thoughts is to use what it says on the cap but just want to make sure, thanks!

 

What's the color of the fluid in your bike? If it's purplish, then it's DOT5.

If you bought fluid, is it DOT5 or DOT5.1? DOT5.1 can be mixed with DOT4, but not the purple DOT5.

 

A 2004 should be DOT 5 silicone fluid, I don't think there's anything special about a Custom that would cause it to be using anything else.

Here's how to tell if what you have is silicone (DOT 5) or glycol (DOT 3,4,5.1):

Take a drop of the brake fluid and drop it into a cup of water. If it mixes and disapears, it's glycol. If it does not mix, it's silicone.

 

Haven't opened reservoir to look yet. I bought DOT 5 fluid.

 

Yeah didn't think being a Custom would make a difference either just wanted to be clear on what bike I have, never know. And thanks for the tip on how to test for what I have. Ill do this when I get home tonight.

 

Ok so I mixed a little bit with water and it dissipated fairly quickly. So guess the cover on my M/C is right and I have DOT 4?

 

Here is a pic of my cover......

 

There's your answer!

 

 

I always get the next mixed up. I have silicone base in my 01. Needs to changed everery so man years. Once you open a bottle, you should use it. Granted we do check our fluid, and don't trhow it out.

It is pricey and harder to get. It has higher boiling point, racers use it. Nice because it doesn't wreck paint. My 07 the other kind, the paint peeled on master cylinder.

Do not mix.