Brake master cylinder dead

[jc971]

Bonjour

J'ai pratiquement terminé ma restauration mais je suis à nouveau confronté à un nouveau problème ..
Je ne peux pas purger mes freins
tout est neuf donc je cherche d'autres causes de problèmes
j'ai perdu beaucoup de temps, j'ai donc enlevé le maître-cylindre de frein et constaté qu'il est mort quand il est neuf.
mais je n'en trouve pas d'autre ni sur WN ni sur rockauto ..
Avez-vous des idées?

 

[autokunst]

I am currently rebuilding my original master cylinder. The bore is clean and not pitted (I have two and one of them was pitted). Rebuild kits are available, cost is about $150 USD. It is a relatively simple re-build. This might be an option for you if the problem with yours is the seals rather than the iron.

 

[jc971]

bonjour et merci pour ta réponse
c'est ce que j'ai essayé de faire hier soir
j'ai trouvé de nouveaux joints
mais cela ne fonctionne toujours pas
alors j'ai ouvert un très vieux maître-cylindre de frein et je me rends compte que j'ai monté 1 joint dans le mauvais ordre
donc ce soir je redémarre et recommence à travailler

 

[deQuincey]

bonjour et merci pour ta réponse
c'est ce que j'ai essayé de faire hier soir
j'ai trouvé de nouveaux joints
mais cela ne fonctionne toujours pas
alors j'ai ouvert un très vieux maître-cylindre de frein et je me rends compte que j'ai monté 1 joint dans le mauvais ordre
donc ce soir je redémarre et recommence à travailler

no hablamos frances,
es un foro internacional y nos esforzamos por entendernos en ingles
quiza de este modo puede ayudarle
por favor

 

[eriknetherlands]

As we would all like to learn from your problem JC971, and the wise advice that you'll undoubtedly get, I ( and others perhaps as well) would appreciate it if you could post your questions in English. Besides not-excluding 90% of the worlds population, it will greatly enhance your chance to get the correct answer!
Here's how I usually do it with my French colleagues: Just type away in your own language, copy paste it into https://translate.google.com/ and post Google's translation, (add the original French if you want as well for clarity).
To be of assistance I translated my own text into French; It may not be perfect, but will understand 90% of the meaning. Google is your friend!

Pour être utile, j'ai traduit mon propre texte en français; ce n'est peut-être pas parfait, mais je suis sûr que je comprendrai 90% du sens. Google est ton ami:

Comme nous aimerions tous apprendre de votre problème JC971, et des conseils avisés que vous obtiendrez sans aucun doute, j'apprécierais (et d'autres peut-être aussi) si vous pouviez poster vos questions en anglais. En plus de ne pas exclure 90% de la population mondiale, cela augmentera considérablement vos chances d'obtenir la bonne réponse!

Voici comment je le fais habituellement avec mes collègues français: tapez simplement dans votre propre langue, copiez-collez-le dans https://translate.google.com/ et publiez la traduction de Google, (ajoutez également le français original si vous le souhaitez pour plus de clarté. ).


- second French post, translated and stored for posterity: -

hello and thank you for your answer
this is what i tried to do last night
I found new seals
but it still does not work
so i opened up a very old brake master cylinder and realize that i fitted 1 seal in the wrong order
so tonight I restart and start working again

A votre service / at your service,
Erik (Eric en Français




Thanks to https://translate.google.com/, but feel free to use any other tool/website/family member/village elder or village youngster....

 

[jc971]

Hello I apologize for this message in French it's a little bug
I admit that I use google translate
So I said I opened the brake master cylinder to change the seals but I think I have reassembled one the wrong way around, if anyone has a photo of the change of gaskets and its reassembly I would be fine

 

[deQuincey]

Hello I apologize for this message in French it's a little bug
I admit that I use google translate
So I said I opened the brake master cylinder to change the seals but I think I have reassembled one the wrong way around, if anyone has a photo of the change of gaskets and its reassembly I would be fine

thank you for making yourself understood

here is some food for your questions:

hope it helps

 

[autokunst]

Not sure if this will help, but here are some photos of my (2) MC guts, in correct order, right as I took them out:

 

[jc971]

perfect
thank you

 

[autokunst]

How critical do you think it is to have/use the "assembly sleeve 6063"?

 

[jc971]

Hi guys
I reassembled the brake master cylinder to put the seal back in the right order
and I notice that 2 new seals that I had fitted are already tearing, it is certainly happening when reassembling, the seals have difficulty entering the body of the master cylinder
what is your method for reassembling?

 

[deQuincey]

Hi guys
I reassembled the brake master cylinder to put the seal back in the right order
and I notice that 2 new seals that I had fitted are already tearing, it is certainly happening when reassembling, the seals have difficulty entering the body of the master cylinder
what is your method for reassembling?

a couple of things on reassembly,
i know that brake fluid is nasty, but wet the seals with it before assembly
and also the cylinder
once is wet it will be easier to install
if the pressure is still too high use a can from your favourite beer or other drink, cut the metal and make a flat sheet 3cm wide and as long as the circumference length of the brake cyl
make a metal sheet cylinder that fits into the brake master and use it to help the seals in

 

[deQuincey]

How critical do you think it is to have/use the "assembly sleeve 6063"?

answered by the ... experimental :

Hi guys
I reassembled the brake master cylinder to put the seal back in the right order
and I notice that 2 new seals that I had fitted are already tearing, it is certainly happening when reassembling, the seals have difficulty entering the body of the master cylinder
what is your method for reassembling?

 

[autokunst]

I think I'll fabricate/fashion my own "assembly sleeve". Rather than using brake fluid, I plan to use Ate assembly grease. I'll also be lightly coating the entire bore with that as it will be sitting on the shelf for a while before going back into the car.

 

[deQuincey]

I think I'll fabricate/fashion my own "assembly sleeve". Rather than using brake fluid, I plan to use Ate assembly grease. I'll also be lightly coating the entire bore with that as it will be sitting on the shelf for a while before going back into the car.

that is excellent, ate grease is very good, but i would use only a little ammount of it

what is very relevant is NOT to use other type of greases,

brake seals are EPDM not NBR, so the use of petrol distilled greases, like vaseline is not correct

regards

 

[autokunst]

Yes, use sparingly. To that, I have A LOT of the Ate assembly lube. If I restore cars for the rest of my natural life, I will not even use a fraction of the grease that I have. So if anyone needs some, and assuming it is legal to do so, I'd me happy to put some into a plastic bag in an envelope and send to you. Just let me know. @jc971

 

[jc971]

Hi guys

after a last attempt to rebuild the brake master cylinder, it still does not work
I made the decision to modify the brakes on my car
I am going to assemble a "simple" brake master cylinder with 3 outputs and front porsche calipers

 

[autokunst]

Forgive me, but that seems like a very arbitrary solution. Couldn't rebuild/replace the existing piece, so we're going to re-engineer an entirely different system, fabricate and retrofit into the car? Seems much simpler to replace the correct MC, in my opinion.

 

[Cornishman]

Here in the U.K. the BMW car club has the tool to insert the seals into the bore, it works fantastically.
I borrowed it from John Castle after a member got two machined up, his one and a loan tool, very kind of them. It is basically a tapered sleeve to help the seal in. I used brake caliper red grease to help lube the caliper pistons, the servo valves and the MC. Note I em referring to The brakes on a RHD car which is very different to a LHD.
My opinion is, worst case, buy a new MC rather than change the entire braking system.

 

[jc971]

Hello

do you think i can use thise brake master cylinder on my csi ?