Finally got the car back on the road and my buddy used dot 3 brake fluid in the clutch master cylinder and i wanna use dot 4 fluid... I was wondering if air would get back in the lines or anything if i took the cap off the cmc and used a turkey baster to get all the dot 3 fluid out and replaced it with the dot 4 fluid i mean i wouldnt be engaging the clutch at all all i would do is remove the cmc lid and use a turkey baster to suck the fluid out until the cmc was empty and then pour in the dot 4 fluid and replace the cap back on the cmc and then start the car and drive it... Or would it be ok to just leave the dot 3 fluid in it but ive read that dot 4 fluid is alot better ne ideas or sugestions ??? Thanks any info or input would be greatly appericated thanks once agian !!!

 

DOT 3 is the recommended fluid and no problems were known because of this. I doubt that there is any performance gain to be realized by switching to DOT 4 fluid. Secondly, just changing the fluid in the master cylinder reservoir is not changing all the fluid. You would need to bleed the entire hydraulic system to get all the DOT 3 fluid out of the lines and the slave cylinder.

 

Iirc, dot 4 has a higher boiling point. That's it.