When replacing master cylinder,most the time not necessary to bleed complete system.
Here"s how: bench bleed master,install,just snug lines have helper pump up,open one line
fluid squirt out,close before no pressure,helper releases but quickly,waits 3-4 seconds
pumps up again,repeat,do this untill no air comes out open line. do next line.
What happens: pushing air out when line is open,when pedal is released quickly and line is closed pulls air that is near by back into master to be bleed again.
Nice hard pedal,test drive.

I bleed brakes myself with a device like this
https://www.napaonline.com/en/p/BK_7769089
Its a hose with a check valve that lets you pump out fluid at the bleeder but not let air in when you stop pumping. No helper required. I also put a block of wood under the brake pedal to keep from getting the master cylinder into the crusty part of its bore.

For a complete flush of the passenger rear caliper i like to exhaust 12 oz of fluid.

A pressure bleeder is ~$25 or you can make one. There are plenty of instructions available online.

You will be doing brakes multiple times and frequently will be doing brake related things that are much more involved than simple "pad slapping" that many McBrake shops do. The $59.99 jobs that make buying a bleeder seem expensive only cover pads.

Times where you need to repack the bearings, change calipers or master or rotors or even flush and replace the fluid all cost more. Many shops are simply using inexperienced, low paid grunts with wrenches that people allow to work on their vehicles thinking a "professional" is handling it.

With DIY, you also get to decide the quality of parts installed and not rely on AutoZoo et al.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

PM me if you need some help and advice. Bleeding brake should be easy, with one person or a helper.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

This.

I owe you a beer, sir. I got it, thanks to this tidbit.

According to all the guides, it instructed me to keep the master cylinder 'Half-full'. However, with these, there's that divider that won't allow the rear brakes to get fluid unless the cylinder is super-full, and even then, through a pin hole.
So, I had ran half of the MC dry, and kept it topped up, but wasn't filling that one side. I spent 4 hours today pulling air through an empty MC....
I feel stupid, but got it done.

Side note, at first this design seemed stupid, but now it seems like a fail-safe in case the fluid gets really low, at least you have brakes up front. Am I correct in this assumption?

Thanks again to all.

You owe hercules not just any beer but one of his choice at the correct temperature

Don't feel stupid, many would have thrown in the towel. You persisted.

Yes that is why the divider is there, on master cylinders with a full size top the problem would have been obvious, not the case here. Look into building your own pressure bleeder you won't regret it!

Anything next on the agenda now that you've taken a brake?

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Glad I could help. How is it that I know this,you got it,happened to me,called

EXPERIENCE.

I might just have to! Tierods are next, but in a few weeks. I need a while to finally just drive and enjoy the darn thing.

Hercules, glad I'm not the only one

If it is because of the boots they can be replaced; but, if the tie rods are worn...got to mine in time just did boots.

Start soaking the sleeves and nuts repeatedly weeks in advance you'll be happier.

Good luck!!!

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Now there's a thought..

But, all my tierod boots are shot, and I get some wheel shake above 70mph so I assume the rods need total replacement?

Hi all, bringing this thread back with a related issue:

One of the soft brake lines I installed is leaking where it screws into the hard line. I have tried cranking it down pretty hard (with the proper flared wrenches) but it still leaks.

The other side, I was able to just snug it down and there's no issues.

I always though thread sealant was a no-go, but Uncle Kent has a kit for this job (of course) and the kit includes a liquid thread sealant.

Assuming using liquid thread sealant is ok, what kind do I need?

Thanks!

Here"s a tip that might help,be sure fittings are clean,apply brake fluid to ends of fittings,
tighten snugly,loosen,re-tighten,loosen re-tighten about ten times,tighten good recheck
for leaks. If there is a slight mismatch of angles this will help to bring together.
Be sure to check closely the fitting ends,for cracks,pits or scaring,may need to use a magnifying glass to check.

Slide back the nut and examine the flare and line. If the flare is distorted or the line broken, you'll never get it to seal.

If I'm not mistaken, the thread sealant in the kit is basically anti seize. It doesn't seal anything because the sealing surface is metal female flare to metal male flare. What it does do is enable you to loosen this fitting 10 years from now or whatever.

Mine will do that. I takes awhile but it does work but with no pressure bleeder I have always left the caps off so I can monitor the brake fluid level.

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84 300D, 82 Volvo 244Gl Diesel