Hi my service manual 2008 Touring Models says Dot 4. So since it doesn't say, it is non synthetic. ???? thanks Mike

 

https://en.wikipedia.org/wiki/DOT_4

 

Thanks, maybe I was not clear in my question I will try again. I am adding fluid not changing it. My service and owners manuals say Dot 4. They do not specify regular or synthetic. I went to Napa they have both. Which came in my 2008 Electra Glide? Thanks again Mike

 

I use standard DOT 4 in my 2008 FLHX and have since 2008.

 

Thanks.

 

I think you are mixing the words synthetic and silicone. Two different words with two very different meanings.

 

Your bike probably came with regular brake fluid. But it wouldn't hurt to mix the two if you are just topping it off. Just make sure you use dot 4.

 

Technically all DOT 4 is "synthetic".... If it says DOT 4, you can mix with DOT 4.

Super DOT 4 (another name for DOT 5.1) is also compatible with DOT 4, just has a higher boiling point.

DOT 5 is silicone based and is not compatible with anything other than DOT 5.

My '03 Heritage is DOT 5 and my '12 Limited is DOT 4.....

I have it written down in my garage and have to double check every time I work on a brake system....

 

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I have " HD's Dot-4 " brake fluid on hand & it says on the label its a Syn brake fluid specifically formulated for HD's & thats about it.

Hope that ans your question.

BTW,dont mix dot-4 and dot-5 brk fluid because in some cases it can cause a bad reaction between them that causes havic in the brake system.

Scott

 

Very true - suffered that indignity firsthand!