Is it ok if I add DOT-3 (J1704) Brake Fluid to Chevrolet Zafira which actualy used DOT-4 (J1703) Brake Fluid ?
I wouldnt. Break fluid is fairly cheap, so its not like your saving much. Although there is very little difference in the performance of dot3 and dot4 (boiling points), Mixing the two is not a good idea. It wouldnt surprise me if they are made of two difference chemicals.
lol4 has a higher boiling point. in a jam 3 would work for me. wouldnt be a bad idea to have the complete system flushed with fresh 4 soon. and its dot-5 that CANNOT be mixed with 3 or 4.
It will work, but you should have the brake system flushed as soon as you can. The only difference between DOT3 and DOT4 is the boiling point (temerature) As long as the DOT3 fluid doesn't get down to the calipers you're okay. If it does it could boil during hard braking, putting vapor into your brake lines, and causing complete brake failure.
