Are all dot 3 brake fluids synthetic?

[richards72chevy]

I'm getting ready to change the master cylinder on my 02 Silverado.The owners manual says to use dot3.I noticed all of the dot3 at O'Reilly say synthetic on them.I've been told you can't mix regular with synthetic.

[Jrainman]

yes I belive all brake fluid is synthetic Dot 3, 4 and 5.1 . from what i have read in the past about brake fluid is Dot 5 can not be mixed because it is silicon based . and will gel up your brake system if mixed with any other fluid,that seems to be the confusion, it is advisable to keep with what your truck calls for if it is dot 3 then use dot 3, just stay away from silicon based brake fluid.

[richards72chevy]

Originally Posted by Jrainman

yes I belive all brake fluid is synthetic Dot 3, 4 and 5.1 . from what i have read in the past about brake fluid is Dot 5 can not be mixed because it is silicon based . and will gel up your brake system if mixed with any other fluid,that seems to be the confusion, it is advisable to keep with what your truck calls for if it is dot 3 then use dot 3, just stay away from silicon based brake fluid.

Thank you Jrainman.

[77c10bowtie]

yeah as long as you don't ever mix the different dot ratings you shouldn't have any issues.