Dot five brake fluid

[Lynn]

I would not even consider changing over an assembled existing system. Dot 3 and dot 5 are not compatible. Don't know about one drop turning it to jelly, but does that really matter? How are you going to remove every bit of the dot 3?

The only time I considered dot 5 was when I was putting my car back together after rebuilding EVERY part of the brake system and replacing the lines with stainless. I know some restorers swear by the dot 5 because if you spill a bit, it won't remove paint like dot 3.

I chose the 3 anyway. I am a firm believer that brake fluid needs to be flushed / replaced every 3 or 4 years regardless of whether the car is driven daily or only occasionally. It is a maintenance requirement, just like changing oil.

[njsteve]

It doesn't turn to jelly if mixed. But they are not compatible. Only put in Dot 5 if it is a new fresh system that has not been filled yet with Dot 3. X2 on the frequent flushing. Dot 5 will go bad over time - when I flushed the Dot 5 in Charger a few years ago it had turned dark yellow from the original purple color. It was 5 years old at the time.

Just over the weekend I looked at the original Dot 3 fluid in our 2001 WS6 Trans Am and noticed that the fluid had turned a dark green. NASTY! I suctioned out the reservoir and refilled it with Dot 3. I will be flushing the entire system in the next week or so to get rid of the rest.

I have used Dot 5 in some of my cars - especially the Mopars since everything is body color under the hood and really hard to repaint if damaged by brake fluid. Dot 5 doesn't hurt paint.