Hi there guys!

I'm running into a head-banging problem with a brake job.

I have successfully replaced my pads on the rear of the car and bled the passenger side with no problem (using a mityvac). On the drivers side I can't pull OR push (with the pedal) fluid through. I bypassed the caliper and hooked the pump directly to the metal brake like, and I still cant pull any fluid. the pump wont build vaccuum either. I know its one line that tee's off for both rear brakes, I can't understand why one side works and the other doesnt! any help would be greatly appreciated. I dont see any evidence of damage to the tee fitting, but there's no fluid running out when I disconnect the metal line.

Any help would be greatly appreciated.

Cheers
Sean

Wonder if it's possible your brake lines are rusted enough that one side is occluded? You could even have a piece of rust/crud blocking one of the lines.

Mine had gotten so bad they leaked slowly, then just burst one day. All brake lines recently replaced... Fuel lines, too - last year.

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'83 300 SD
'68 Triumph TR 250 - The only car I ever loved more than the Mercedes; who needs electricity, anyway? - Damn, why did I sell it?!
'59 Jaguar 3.4 'Le Chat Noir' - Damn, why did I sell it?!

It's difficult to make predictions, especially about the future.
- Niels Bohr

I did pull the metal line and was able to push air through it without any trouble.

An update:

went back to the rear passenger side and tried bleeding it again just for fun. now I can't pull anything out at all.

went to the master cylinder and broke free the line going to the rear. no fluid came out. pulled the line out, nothing. there's plenty of fluid in the master cylinder. cracked loose the front passenger side and fluid started to run out. Why all of a sudden no fluid to the rear line? I've heard of some american cars having a combination valve that cuts fluid to the rear line under circumstances... apparently you just open one of the front bleeder valves and it resets. tried that just incase the w123 had something similar but no dice.

any ideas greatly appreciated. is my master cylinder shot?

Sean

In both compartments? You might try refilling the reservoir just in case. Then try the conventional bleeding procedure.

The W123 is not so equipped.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

The Mityvac is a poor way to bleed brakes because sucking on the loose bleed screw will suck air around the threads. If you have a gunk plug in the bleed port on the caliper, you can suck only air. In that case one can unscrew the bleed screw and use a wire to clean out the port, screw the bleed screw back in, open it slightly and try again. With a vac method you will always have some air bubbles in the fluid coming out so you just have to ignore that. A pressure bleed method is much better and easier even if you just use only air pressure on the master cylinder.

PS your mention of no fluid at the master cylinder sounds like you had sucked the rear portion of the master cylinder dry when you bled the first wheel, as tangofox suggested.

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'97 E 300 D

Agreed. The Mityvac instructions call for greasing the bleed screw threads to alleviate that problem.

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When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

Agreed about the mity vac. Try doing it the old fashion way, with a helper....get a neighbor kid to help, give him 5$...put a piece of wood or rock under the peddle so it doesn't go all the way to the floor....make sure both reservoir are full, start at the rear passenger, rear diver, front passenger, front driver...

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Guys - thank you all for your quick responses.

How does the saying go? the loosest nut is the one behind the wheel...

I had "filled" the reservoir up to the max line... but just shy of the opening leading to the second compartment.

So starting from the beginning, i actually just about drained the 'rear' reservoir bleeding the pass rear brake, then completely emptied it while doing the drivers side. then of course nothing came out when I went back to the pass side, and why it was dry when I cracked open the rear master cylinder line.

filled up BOTH reservoirs and of course bled as expected. Wont get those 3hrs back! =)

FYI, after much reading decided to go with new zimmerman rotors and PBR deluxe pads. I'll report back any good/bad experiences.

Thanks everyone--

PS, mityvac (I actually have the powerbuilt model) did the trick quite well! If I feel anything weird in the next few days I'll do it the old fashioned way.

Cheers,
Sean
85 300D "Sonny"
Ukiah CA

Nailed it