I have a 2008 Buick Enclave, and about two months ago I needed to add some break fluid. I added about 4 ounces DOT 3 synthetic fluid. I found out that if the original fluid was not synthetic, it is not a good idea to mix them.
The owner's manual specifies only DOT 3 with no mention of synthetic or not (probably because synthetic may not have been around at that time).
The question is, should I have the break fluid changed out (if the original oil is non-synthetic) or is it OK just the way it is?
Thanks,
Dave