dot4 - dot4 synthetic brake fluid compatibility ?

[Max]

I currently use regular dot4 brake fluid and need to know if it's ok to top up reservoir with dot4 synth. The container states ok to mix with dot 3 & dot 4.

A quick check on the weeb says - a) don't do it, b) it's ok, c) why would you mix them ?, d) ok to mix with 3,4 & 5.1, e) if you mix both types of 4 you end up with dot8 harhar,

and last, all dot 3,4, & 5.1 are already synthetic. The last one threw me.

My reasoning for c), this was first time I couldn't find regular DOT4 at my go to store.

[djh3]

I seem to remember something about the DOT 5 will hurt the rubber parts on our bikes. Look thru the second gen tech section and maybe search brake fluid or DOT4

[Max]

I seem to remember something about the DOT 5 will hurt the rubber parts on our bikes. Look thru the second gen tech section and maybe search brake fluid or DOT4

 

as you suggested djh3, did a dot4 search and couldn't come up with a dot4 & dot4 synth compatibility answer.

[MiCarl]

dot 3,4, & 5.1 are already synthetic. The last one threw me.

 

You ever hear of a brake fluid well or farm? They're all synthetic.

 

Don't let the marketing department cause you to lose sleep. The whole point of having a standard is to ensure uniform performance and compatibility. Any DOT4 is just fine. That's part of the point of having a standard in the first place.

[Max]

You ever hear of a brake fluid well or farm? They're all synthetic.

 

 

Never heard of either till now. Thanks for the info.

[djh3]

I am almost at point of a rear tire change. Thats usaualy one of my indications for brake/clutch bleed time. So I was in auto parts store and picked up some DOT 4fluid. I looked for probably 5 min. Every DOT said Syn on it. So DOT 4 Syn is what I got.

[BlueSky]

http://www.venturerider.org/forum/showthread.php?107983-Informational-video-on-brake-fluid

 

Watch the video from BikeBandit. It's good info. I believe they say that Dot 3, 4, & 5.1 are compatible.