Brake Fluid - DOT 3, 4 or 5 What are you using?

[73CJ]

Since todays project is pulling off a sticky caliper for me, I thought I'd ask:

What type DOT brake fluid are you folks running?

I've been using DOT 5 an internal corrosion has quit. My wheel cylinders were always pitting DOT 5 stopped that. I upgraded to 4 wheel disks years ago with good success. I spend alot of time in the mud. Not sure what I'll find today. Maybe a rock? More later.

 

[BusaDave9]

DOT 4 can't be mixed with DOT 5.
To switch from one to the other it is recommended to replace brake lines. You are not supposed to put DOT 5 into a brake system that had DOT 4 in it before.

DOT 3 and 4 are based on glycol and can absorb oxygen.
DOT5 is based on silicon. Although DOT 5 has a higher boiling point and is considered better it really isn't. In my Busa I use Super Dot 4.
DOT 5 actually compresses a very slight amount. The brake pedal is not as firm as DOT 4 but you need a high performance car and braking system to notice the difference.

If you have been using DOT 5 i would not switch ot DOT 4 - or vise versa.