I changed my brake pads and filled my resovoir back up with DOT3. I just had to change my rear PS caliper and I noticed before I bled my system the resovoir says DOT4 only. Well, I didn't put any more DOT3 in it, however, I do have about 10 ounces of DOT3 mixed in with the fluid. Is this going to cause problems or will I be okay. I hate to flush my system but if need be I will. Thanks!

 

I would not risk having mixed brake fluid in there.

 

yeah man, brakes are definatly not something you wanna be messing around with. you're gonna wanna flush that. after all... what's the only way you're gonna find out if your brakes are working?

 

We are supposed to change the brake fluid every 2 years any-way.

 

it's not going to do any damage, it's not a big deal, the only difference between the two fluids is the boiling point. i've mixed the two fluids many times (mostly in motorcycles, but the systems are the same)

 

yeah its dot 5 that is drastically different from 3 and 4, I believe... I've heard mixing the 2 is fine -- wouldnt want it in my car... but whatever.

 

yes, you definitely do not want to mix dot 4 and dot 5 fluid, that will basically ruin your whole brake system (one is glycol-based and one is silicon-based)