Changing Brake Fluid

[Quickstep192]

I’m about to do some work that will require temporarily disconnecting one of the brake lines at the tunnel.

This seems like an opportunity to replace the brake fluid.

What’s most foolproof way to get the old fluid out and the new fluid in?

I have an oil change vacuum pump, but I don’t have a way to pressurize the master cylinder reservoir.

Any suggestions?

[bkreigsr]

I use a turkey baster to suck to the bottom (almost) of the reservoir. Then use cotton swabs to clean the bottom of the wells.
FWIW, the system will drain itself with no mechanical aids - gravity.

[EC900]

Pre-soak those brake bleeder connections with penetrating oil well ahead of time, reapply PB Blaster for couple days isn’t too much. Have plenty of fresh brake fluid on hand too.

Doing flush solo takes time. Foot method is a standard, no frills way to bleed.
Removing as much of old fluid from reservoir, clean up bottom, and then refill with fresh fluid, replace reservoir cap…REMEMBER TO PLUG THE OVERFLOW HOSE/OPENING OR FLUID WILL BE ALL OVER EVERYTHING !
- Opening the furthest bleeder (R/R), having a hose connected to bleeder and hose into a catch jar filled with fluid (hose kept below fluid level) to avoid air entering.
- Depress brake pedal lightly and slowly few times, then get out and monitor old fluid in catch jar for color clarity AND keep reservoir filled, until that line is satisfactory clean, tighten bleeder fitting.
- Repeat that process on other side and so forth.

Using the vacuum process, the cap can act as the pressurization….just as when doing it with the foot method.
Would work with vac (12 psi) but I think it would quickly draw the fluid very fast and result in air entering. But either way, with overflow hose must be blocked/closed up, also which the vac you have, it should come with a large capacity reservoir bottle attachment that holds clean fluid to draw down from resevoir not necessarily pressurizing but keeping it sealed from outside air entering.
I don’t care for generic bleeder systems unless its seals properly on the 911 reservoir.

[Marine Blue]

I used a handheld Mityvac vacuum evacuator and it worked like a charm. You just need to make sure you keep the reservoir full so you don’t pull air into the system. Also note that the clutch slave cylinder intake is slightly higher than the brake line intakes so keeping the reservoir topped off will be important when you bleed this line.