Good afternoon. I have fallen culprit to the airbag issue in my 2010 cobalt ss so my car is just sitting in my garage while I wait for an appointment to open up at the dealership. I was looking over my car while it sits there motionless for anything else the dealer might need to do. The brake fluid seems to be needing a change. I have a few bottles of Motul 600 (DOT 4) laying around and was wondering if this is a suitable replacement for the Cobalt. Worked great in my Scion tC. Should I get dealer to do it or use the Motul 600? If not Motul 600, what brand, etc.?

 

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Incorrect.

DOT4 and DOT3 fluid is compatible and using DOT4 in DOT3 recommendations raises the boiling point of the fluid helping with brake fad when heated.

Combine DOT3/4 with silicone based DOT5 and you'll have a mess on your hands.

 

Yup your right the did my reading again and yup seems like the only difference between dot 3 and dot 4 is the boiling point. I would still stick to dot 3 either way, but that's just me. And how does your fluid look?

 

My fluid looks pretty terrible. I am at 57k miles and I do not believe it has never been changed. I have only owned the car for about 8 months. I have read other cobalt owners using ATE Super Blue and I guess I'll have to research the difference between this fluid and Motul 600. Maybe Paul @ Dezod knows what is best to use!

 

Last i checked mine its still looks like new i havent changed the fluid yet but it could of been changed before i got the car

 

I run them motul in mine. I track it too. it will be fine

 

Have you bled your calipers yet? That's where it'll look really bad.

 

Yup last time i check was when i had to replace my caliper so had to do it and it looked good to me that was maybe 1k or 2k ago

 

I ran with DOT 4 when I had a Cobalt, an 09 Cobalt SS, with a few track days and never had an issue. I know the guy who owns it now and I don't think he's had any issues with the brakes either.

 

Absolutely no reason you can't run DOT4. There's also no reason to have the dealer do it. Just grab a buddy. Three people is ideal unless you have a hand pump. The front wheels don't even need to come off with the brembos.

 

Dot 4 is perfectly safe, you can mix it with dot 3 if you don't have enough. Personally i was taught to change dot3/4 brake fluid about every 2-3years or every 20-40k. Each depending on your average climate, more humid year round the shorter the "safe" lifespan of the fluid. After the fluid reaches about 4-5% of moisture content the boiling point has reached dangerous levels.

When you change out your pads never, SERIOUSLY NEVER, push the caliper back in without opening the bleeder so the fluid in the caliper goes out instead of into the system. Although alot of ppl do it and never have problems, the fluid can "gum up" at the caliper from being through so many heat cycles and when that thicker fluid goes back into the abs, it can cause it to fail when you need it at your next emergency.

Sorry for the mild speech lol. Personally i gravity bleed my system bc i change it often enough it keeps a low viscosity. After you flush the system normally i recommend either if you have a scanner to do a full abs cycle and flush it again, that way you get the old luid out of all of the circuits and valves in the abs.

 

Thanks for the feedback! I will continue to research but this is a good start.

 

FWIW, I've only ever used Prestone synthetic DOT4 from my local auto parts store and have never had a brake fluid fade, even when I melted the backing plates on my old Echo.

 

There's not a whole lot to research. Motul 600 will be perfectly fine. I run it all the time on the track and I also Dd the car with it. You will be fine.