87 Chevy brake fluid type

[Jerr-conn]

Topped off brake fluid yesterday. Didn't realize it was dot3 synthetic. Am I supposed to have
Regular dot3 or synthetic or what?  However, I did not pump pedal after topping off. So l
Siphoned the fluid out of the master cylinder. As soon as I am sure what fluid to use, I will
 Fill master cyl. I'm new to trucks, and I know sometime ago they went to synthetic fluid, just
Don't know when.  Thanks.    Jerry

[1967KaiserM715]

Dot 3 is dot 3, dot 3/4, dot 5.1, are all a glycol based fluid. All have different heat ratings and boiling points.

What you do NOT want to do is mix synthetic (3, 3/4, 5.1) with silicone based fluid (DOT 5).

DOT 5.1 and DOT 5 are NOT compatible, even though the numbers are similiar.

And as an FYI, DOT 5 cannot be used with ABS equipped trucks, the rapid pulsing of the pistons can actually make the fluid "froth" and may create air in the system.

Sent from my SM-S920L using Tapatalk

[Jerr-conn]

Thanks 67 kaiser

[VileZambonie]

People tend to think brake fluid is eternal. If it has never been flushed, now would be a good time.

[Newant]

So, in the end what type of fluid did you use?! My dad's 87' Chevy is also having the same issue right now. Actually, he had a very bad brake fluid leak a couple of months ago, and I think that he should really change to whole brake system, as it is not the first time when he is facing this kind of issues. He has tried a lot of brake fluids however he does not know which one is the best. After reading an interesting article on cararac, I told him that the dot3 is the best one, however he does not agree with me.