Brake Fluid?

[Brandon]

Need to do a flush.  I know the formulas have changed over time -- what do folks use nowadays?

[JD]

If you are just flushing/replacing you probably want a DOT3/DOT 4 fluid.  Use a major brand.

There are a few opinions and preferences on this topic, like there is on engine oils, others will chime-in.

Type of use of the vehicle can factor in too.

[Royce Peterson]

Stock was Dot 3. That's what I would use.

[rhjanes]

You need to replace with the same fluid type that is already there.  Unless you are also rebuilding the entire system.   When I rebuilt the brakes on my old cars, I went with all new rubber stuff and went with DOT-5 (Silicone).  It was a good choice for me as I use my collector cars (don't go road racing where heat can overwhelm silicone).  I've not had to flush or bleed the brakes in decades of light use.  Dot-5 doesn't absorb moisture so my 25+ year old fluid still looks clear and functions fine. 
But if you are simply flushing the system, use the same fluid in it already, most likely DOT-3.

[NC TRACKRAT]

If, in fact, it is DOT-3 in it now, I highly recommend MOTORCRAFT High Performance Brake Fluid.  In all the events I ran our '95 Cobra R, the brakes never failed me. 

[Bob Gaines]

Also keep in mind that Dot 3 or 4 brake fluid will eat the paint if leaking from a fitting or bleeding the brakes . The silicone will not eat the paint when the inevitable happens and brake fluid leaks from a master , wheel cylinder or proportioning valve. If that is low priority then disregard. Silicone has other plus qualities like that have been mentioned. As has been mentioned changing over to silicone is a major job and best started during a restoration process when all parts have been refreshed. dot 3 and 4 also have their plus's and are overwhelmingly preferred when open track driving of your car.  I just wanted to do a little explaining for the uninitiated as to why some people use the silicone. It boils down to a personal choice based on how you plan to use your car.

[s2ms]

I do a complete flush every 3 years, been using Valvoline DOT 3/4 synthetic for as long as I can remember...

[JD]

I do a complete flush every 3 years, been using Valvoline DOT 3/4 synthetic for as long as I can remember...

+1

[oldcanuck]

Stock was Dot 3. That's what I would use.

+1

[greekz]

I have used silicone in both cars for 30 plus years with no problems at all. 

Greek