Newish brake master is leaking at res seals

[Das Delfin]

Hi guys,

Doing some while-you're-in-there bs on my car. A few years ago my (original?) brake master cylinder failed after a drive down the mountain, so I replaced it with an AZ one. Now I'm redoing a lot of stuff in my car and have turned my attention to the master cylinder. Check it out:



As you can see it was leaking from the res seals. I had replaced the reservoir AND its seals a few years ago along with the new master. I read everything there is to read and made sure I did it correctly: I installed the seals into the master, then the res into the seals, then bench bled everything and then put it in the car using lots of paper towels.

I'm planning on returning it under the lifetime AZ warranty and getting a clean one because it's going into this:



but I don't want it to leak like it did before. As far as I can see, I did everything right. Why would it leak the way it did? I want to make sure it's done right this time because a brake fluid leak all over my new paint would be just be too much. Any input?

[e30davie]

Looks pretty rusty for only being a few yrs old.

I bought new reservoir seals for mine from the dealer, were cheap as. Might be an option for you.

[15Michaeljoseph]

I still say get the new one and don't stress out about it. Make sure you press the reservoir in as tight as possible and don't spill any brake fluid when bleeding/ filling, and clean it up ASAP if you do

Not to thread-jack but does anyone know how to fix a broken brake line flare tool?

Sent from my moto g(6) using Tapatalk

[nrubenstein]

I’ve had bad experiences with some of the aftermarket reservoir seals. At this point, I will ONLY use genuine ones, even on a fresh rebuilt master.

[AndrewBird]

Only thing I have to add is to lube the bushings with a little brake fluid before you put everything together. If you put it together dry, you could tear the seals.

[Das Delfin]

^ thanks guys. I had read to not let brake fluid contact the seals (which doesn't make sense really) so I'll be buying two genuine ones and lubing them up when I go to install.