MC-71 Posted February 9 Share Posted February 9 Can synthetic dot 3&4 be added to non synthetic brake fluid or do I need to flush the whole system? I’m trying to find a 32oz old dot 3 brake fluid that is a known brand like Valvoline. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted February 9 Share Posted February 9 (edited) No it can't, you do have to flush out the system completely they are not compatible! Wait a minute ALL brake fluid is synthetic I was thinking silicone that's different. Sorry I got a little confused I'm on my first cup of coffee ☕️ 😅 Edited February 9 by cny first gen 71 Change 6 Quote Link to comment Share on other sites More sharing options...
jft69z Posted February 9 Share Posted February 9 Yeah, as long as it's DOT 3 or 4, it can be added to what you already have. Like Steve said, if it was silicone, no way. That being said, brake fluid is hygroscopic, which means it absorbs moisture and should be changed/flushed occasionally anyways. If you haven't done it for years, this may be a good time to do it. 5 Quote Link to comment Share on other sites More sharing options...
stangeba Posted February 9 Share Posted February 9 I should (we all should) add a sticker to the top of the master cylinder as to what DOT brake fluid I am using. I think it's 5. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted February 9 Share Posted February 9 3 hours ago, stangeba said: I should (we all should) add a sticker to the top of the master cylinder as to what DOT brake fluid I am using. I think it's 5. I don't have to worry about that Bruce No one else ever touches my car but me. Only exception is yearly inspection and Bob handles that so I don't worry about him. I would let him work on my car. He works on my truck too. 2 1 Quote Link to comment Share on other sites More sharing options...
cbolt Posted February 10 Share Posted February 10 I can never remember which fluid type is in which vehicle so i keep the container with a decal which says what vehicle the fluid type is in. Sounds kind of crazy, i know, but I have 7 vehicles all requiring brake fluid and not all have the same fluid requirement. Then when its time to flush and fill I know what kind to purchase. 2 Quote Link to comment Share on other sites More sharing options...
Montemedic Posted February 10 Share Posted February 10 James, I agree with you. I have 7 vehicles at my house too. I took a paint pen and put a small number on the master cylinder cap or brake booster for the type of fluid that it requires, or is in it. It makes life much easier. 3 Quote Link to comment Share on other sites More sharing options...
420ponies Posted February 10 Share Posted February 10 Just got my disc/disc brake master cylinder and " voids warranty " if I use dot 5 .Guess what, I'm using dot 5 in my Monte. I'm a little pissed that they didn't mention it when I paid for it. I've had dot 5 in since 2008 and no issues with disc / drum master cylinder on it now. I just don't get it. I thought it was better fluid since it doesn't take paint off my car. Plus, suppose to not collect moisture. We have some steep hills here in Western New York State and no problems with braking in it. P!us I've taken it to Watkins International Race way , drag raced it too. Corvette Central is the seller. I'm going to chance it ! Quote Link to comment Share on other sites More sharing options...
MC-71 Posted February 10 Author Share Posted February 10 Thanks guys. I ordered Valvoline Dot 3 or 4. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.