Brake fluid capacity?

[wegngis]

I'm doing a disc brake upgrade, and I'm wondering how much new brake fluid to purchase. Essentially I've got the whole system torn apart so I'm looking for the full capacity.

 

[spray1963]

With all the bleeding you will be doing I would go ahead and get the big can.

 

[needabronco]

If your starting off fresh I'd say you'll need a quart, maybe another pint by the time your bled. Remember that brake fluid absorbs water from the atmosphere, so once that can is opened time starts ticking, so you don't really want too much brake fluid laying around, so don't go out and buy a gallon.

 

[Glass Pony]

A quart will do it.
I started all new master cylinder, calipers, wheel cylinders, and brake lines. Had some left over in a qt. bottle.

 

[wegngis]

DOT 3? This is a disc brake conversion

 

[Apogee]

DOT 3? This is a disc brake conversion

Yes, DOT3...or DOT4...or DOT5.1...doesn't matter as they're all glycol-ether based brake fluids and compatible with one another. You most likely won't ever need the higher wet/dry boiling points of the DOT4 or 5.1 fluids, however it wouldn't hurt anything to run it, except for your wallet maybe. The best thing you can do for your brake system is to flush your brake fluid at least every 2 years.

 

[DirtDonk]

The best thing you can do for your brake system is to flush your brake fluid at least every 2 years.

True words those! Wonder how many people actually do it?
I know I do it more regularly than most people I know, but even at that I typically let it go more than two years. But not many more!

Oh, and isn't DOT 5 the silicone stuff? (edit: sorry, I see you said 5.1)
I personally use it, but as many manufacturers have certain restrictions and recommendations against it, you should be careful what you put it in. Unlike me, who decided to experiment with my own stuff so that I could get something that didn't eat paint when it was spilled. But I'm willing to take that chance with my own stuff.
Never have figured out what, if anything, in a brake system would be incompatible with silicone brake fluid. Maybe seals of course, but never had any issues with mine. Four cars and thirty years and no issues. At least not that I'm aware of!%)

Paul

 

[DirtDonk]

Sorry, didn't see the "5.1" that Apogee posted. Thought I saw only the 5 part. My mistake.

Paul