Re: Brake fluid

Posted by Bob E. On 2020/6/1 9:15:36

The DOT3 and DOT 4 you see in all the stores are labeled synthetic. That is okay as all brake fluid is synthetic. It is the DOT5 you want to stay away from for a stock car, as bkasmer stated, as that is a silicone based product. That will cause problems with rubber seals not designed to handle DOT5 fluid.
I use DOT3 in my Patrician, buying the small, yellow Prestone plastic bottles available most places. The bottles say Synthetic like every other brake fluid out there, whether the are marked that way or not.

DOT4 can be used and mixed in too, it just has a higher boiling point. (Oddly there is now a DOT 5.1, which is more like 3 and 4 as glycol based, which would be okay too at an even higher boiling point)