Draining Brake Fluid

[Jetaway]

Folks,

Maybe an obvious to everyone but me question, but how does one drain all the brake fluid out of the lines?

I'll be starting on the rears (1972 240Z) Thursday or Friday. I'm planning on rebuilding the wheel cylinders and if need be, I'll replace them. The brake fluid in the rear reservoir is very dark and almost crusty looking compared with the fresh fluid in the front reservoir. One way or the other the wheel cylinders will be cleaned of the old fluid so I figure this is as good as time as any to get the lines as clean (i.e., removing old brake fluid) as possible.

Can I just disconnect both brake lines, run tubing to an appropriate container and push the brake pedal until nothing comes out?

Or should I use the bleeder screws on the "old" cylinders and bleed away while not refilling the reservoir?

Whichever method above is correct, should I, instead of just letting the master cylinder run dry, keep it topped off with fresh fluid until new-looking fluid comes out the other end?

Chris

[240260280z]

Use a turkey baster to draw the fluid from the reservoir.

Top up the reservoir with new fluid.

loosen the rear left brake bleeder and hook a clear drain tube to it and into an old container (oil, washer fluid, etc)

Pump the brake pedal to flush the old fluid out. Keep topping up the reservoir.

Watch the colour of the drain tube... when you see clear fluid, close the bleeder.

Move to rear right then hook up bleeding tube and pump fluid through until it is clear. Closeup then move to front right then front left.

Finish the job by bleeding/flushing the clutch line.

Have a friend rather than wife or gf do the pumping.

[Jetaway]

Blue,

Makes perfect sense to me, thanks.

Oh -- already taken care of your last suggestion, but how do I explain the "funny" taste in her baster?

Chris

[SteveJ]

Just look at your local Wal-Mart or dollar store. You'll find them cheap there. I have a couple in the garage for brake fluid.

[240260280z]

yes. For sure, never use anything from your kitchen that you will reuse. Use the new one in you kitchen and use the old one for your car... btw it is Thanksgiving in Canada this weekend so it would go down particularly bad there if you took the baster. You will get a kick out of this post:

http://www.classiczcars.com/forums/showthread.php?43149-Kitchen-Duty-Tools-for-cleaning-(typically-carbs)-with-solvents-and-staying-clean.&highlight=kitchen

[Bonzi Lon]

I have found at the drug store or vet clinic, various sizes of syringes, without needles. They come in sizes of 2cc and up, a length of tubing gives more reach. The rubber plunger seems to be oil resistant, been using the same one for 3 years, brake fluid, gas, oil, etc.

I've used them to drain the brake & clutch reservoir, put 2cc in the carbs, large one & tubing to fill the trans & diff, drained the gas tank from a mower rather than turning up side down, removing small amounts of fluid for inspection, even have one packed with grease for spot application.

Bonzi Lon

[John Coffey]

Using ATE Super Blue as the new replacement fluid makes the whole process a lot easier. You will know when the new fluid is at the calipers/wheel cylinders.

[SteveJ]

Using ATE Super Blue as the new replacement fluid makes the whole process a lot easier. You will know when the new fluid is at the calipers/wheel cylinders.

If the fluid is brown from age, he'll be able to tell sure enough when the fresh fluid comes through...that is providing the lines are not clogged with rust.

[sblake01]

To drain/replace the fluid, I use my power bleeder. I go from wheel to wheel, in the same order you would for bleeding, until there's no more dirty fluid. Of course, topping up the master as I go along.

Edited October 10, 2011 by sblake01

[ZCurves]

Ditto.

[jccampbe2001]

How do you bleed the Master Cylinder, is it as simple as opening one of the bleeders while pumping, and then do it again on the other

[beermanpete]

How do you bleed the Master Cylinder, is it as simple as opening one of the bleeders while pumping, and then do it again on the other

Yes. The procedure is the same as bleeding the wheel cylinders except you are working at the master.