Special Brake Fluid Capacity - Bleeding

[dontlikeoc]

How much brake fluid should I expect to have handy when I bleed out the entire front brake system? It currently has a 30 yr old fluid and soft brake lever and I am rebuilding the calipers. I am wondering 16 OZ of leftover DOT4 may be enough.

I cannot have too many excess bottles lying in my apartment or my wife will complain.

[DGXSER]

I am not sure but that may well be enough. All depends how much you spend or expell during the bleeding process.

Before you reassmeble it all and put new fluid in, make sure you clean out the lines really good with brake cleaner as well.

[TomRodgers]

IMHO, i would grab a new bottle, quart size. if you need to, leave it in your car/truck!!!

so far, trying to bleed the brakes on my standard (fronts) i have 'wasted' about a pint so far. leaks, broken banjo bolt, all kinds of issues..... better to have it and not need it, than to need it and not have it!!!!

[dontlikeoc]

DGXSER,

Thanks for your reply as always. Knowing what to expect really helps.

[CatatonicBug]

I was always taught that "left over" brake fluid should NEVER be used for anything but cleaning parts. once you break the seal on the bottle, it starts to absorb moisture from the air (even with the cap on), and that is what kills the fluid. It's cheap enough, I would go get a small bottle and toss the old one.

[DGXSER]

C-bug, I think that is a rule set by the folks who sell brake fluid. All I know is that I have used a bottle for years and never had any corrosion or seal issues in my braking systems. Now I would not leave it sit with the cap off forever,and try to limit the amount of air it is exposed to.

But if you really go that far with it, then how the heck does the fluid stay good in your MC? They dont get filled to the point the rubber seal pushes all air out. There is a limited amount of moisture in the air that the fluid is exposed to and it can only absorb what is there. Keep that amount of air as limited as you can. JMHO

[CatatonicBug]

Yeah, you're probably right. I just figure the stuff is so cheap, and I do brakes so seldom that I just go and buy a new $3 bottle each time I need to use the stuff.

[fredintoon]

Yeah, you're probably right. I just figure the stuff is so cheap, and I do brakes so seldom that I just go and buy a new $3 bottle each time I need to use the stuff.

Hi 'Bug,
when both my boys lived at home and all the bikes and cars we had between us, I bought brake fluid by the gallon jug.
When they and the gallon were gone, I bought a quart.
When I built my Eric's sidecar rig and we both fitted s/st brake hoses to our bikes last summer that quart got used plus half the new one we had to scurry down to Canadian Tire and buy.

[dbeardslee]

Speed bleeders make the job a lot easier. You can find them at most autoparts stores.