Are DOT 3 and DOT 4 interchangeable? If not what damage can be done by using DOT 4 when DOT 3 is specified? I noticed that the guy who changed my caliper and brake hose today had a bottle of DOT 4 next to him while changing my caliper and brake hose and my truck calls for DOT 3. The brake fluid resevoir is also overfilled. Does it matter that its way past the MAX mark on the resevoir or not? Please advise.

 

Did a google search and as it turns out you can interchange them but not DOT 5. I was a bit panicky earlier and hadnt taken the time time to research my question. Still worried as to whether the resevoir being overfilled will be detremental to brake perfromance. Both front rotors were replaced front passenger caliper and brake hose and all the pads. I know as the pads wear the fluid level will decrease in the resevoir but as of right now it is way over the MAX fill mark. Should I take from the resevoir until the level meets the fill range or leave it be. Any thoughts?

 

To clarify DOT 4 can be used in place of 3 but DOT 3 cannot be used in place of 4. Dont want to put any false info out there.

 

thats correct

 

also too much shouldnt be a problem but if your worried just bleed some out.