dismantling master cylinder

[jan lauwers]

Gentlemen,

I am trying to open up my brake MC. Dispute a good description in Haynes and MB book, I am stuck: I can't remove that white washer... looks like a nylon ring around the shaft. (See photo). The other seals and washers so far came out very easily, not this one. Any tricks here please? I am trying with a small thin screwdriver, while I push the cylinder...no luck.

Thanks friends!

Jan

[Benz Dr.]

Why are you taking it apart?

[jan lauwers]

It's a chain reaction. While my engine is out, I noticed some worn out rubbers on the front axle and subframe. Then I decided to replace the flex bake lines, wanted to empty the braking system, then noticed that the reservoir is full of dirt....the MC is not looking so good.... so now I think, while I am here, why not buy a revision set and redo the MC as well?

Jan

[Shvegel]

You could try compressed air on the fittings for the brake lines but that would be a last resort for me as the potential for mess and getting brake fluid in your eyes etc might not be worth it.  Honestly the plastic bushing just slipped in there when it was originally assembled so you probably have some corrosion in the cylinder bore which means you may jump through hoops to get it apart only to find that it isn't safe to rebuild.

[ja17]

Remove the small 10mm head hex on the bottom of the cylinder first. Next push the spring loaded piston all the way in and then let it "snap" back outward. After a few cycles of this it will pop itself out. I use a home made assembly fixture for re-assembly.

[Benz Dr.]

I won't rebuild a MC for liability concerns. You shouldn't either; you being the driver and all, if you follow me?

[ejboyd5]

I won't rebuild a MC for liability concerns. You shouldn't either; you being the driver and all, if you follow me?

I would suggest that what a competent mechanic does for his own use and what he is willing to offer to a litigious public are entirely different matters. 

[Shvegel]

For my car I just bought a new one but I would trust my own work for a rebuild over any "rebuilt" master cylinder.  On the ship I work on I got so tired of problems with Caterpillar factory rebuilt parts that I now do all my own water pumps, alternators, starters, turbos etc.  The last straw was a rebuilt cylinder head where they had over bored 2 of the injector bores so I spent the next 4 years (16000 hours) using a slide hammer to remove 2 out of 4 injectors on that engine.

[Benz Dr.]

I would suggest that what a competent mechanic does for his own use and what he is willing to offer to a litigious public are entirely different matters. 

Not at all.
This is the most important part of your car. There is no worse feeling than having your brake pedal go to the floor just before you run into something. I have to be an advcate for the safety of my customers but I take that much further by bringing my expirience to this form on matters of real importance. If I didn't care, I wouldn't say anything; and I do, so I did. 

[jan lauwers]

Gentlemen,

Thanks for raising the safety issue, I entirely agree and I am going to buy a new MC. It is some sort of curiosity that makes me want to open it.
I am not going to do that now...because I cant remove that ring.
My plan now is:
 
Put the old cylinder back in with the reservoir and the old rubbers.
Flush the system with methanol
Remove old rubbers and replace flex brake lines with new ones.
refill with new BF
Bleed

Questions:
Good plan?
People here talk about methylised spirit to clean the lines. Is that we call methanol here in Europe?

Thanks for all the help guys
Jan

[hauser]

If you're doing all this work why not replace the reservoir with a new reproduction from Babak?  It is an exact copy minus the ATE markings.

[Jowe]

I replaced my MC (early 230 style) this weekend. It was a fairly easy job. I cleaned the reservoir inside and outside and it now looks nice with the yellowish patina. I also replaced the reservoir mounting and rubber bushings (sold separately). I flushed the system with fresh ATE Type 200 DOT4 brake fluid. BTW, I used a really nice unit to pressurise the system - with tyre air! Then, I didn't need to depress the brake pedal att all. The trial run afterwards confirmed great brake performance.

The pictures shows the old (notice worn rubber seal against booster) and new MC and the brake pressurising unit. Good luck with your work!