[AntnyL]

First the vitals: I'm using an underfloor brake system master cylinder, disk/disk brake setup. Tired of breaking my knuckles and back just to check the fluid level. So I am installing a remote reservoir type M/C cap, and a remote reservoir on my firewall. I ordered a billet remote reservoir from Autoloc ("Zirgo" brand?) and noticed that the cap is not vented.

So here's the question: shouldn't the remote reservoir cap be vented, to allow the fluid to flow down by gravity into the master cylinder?

[cobalt327]

Originally Posted by AntnyL

shouldn't the remote reservoir cap be vented, to allow the fluid to flow down by gravity into the master cylinder?

There needs to be a way to equalize the pressure, under the cap there may be an "accordion" seal, like OEM MC's have.

The problem w/having the remote reservoir cap vented to atmosphere is the brake fluids hygroscopic nature- it will pull water from the air and soon the fluid would be contaminated.

[AntnyL]

Originally Posted by cobalt327

There needs to be a way to equalize the pressure, under the cap there may be an "accordion" seal, like OEM MC's have.

The problem w/having the remote reservoir cap vented to atmosphere is the brake fluids hygroscopic nature- it will pull water from the air and soon the fluid would be contaminated.

The M/C cap that I got from Kugel has this seal. The fluid inlet ports on the cap (that you connect to the remote reservoir) let the fluid enter from above the accordion.

[cobalt327]

Originally Posted by AntnyL

The M/C cap that I got from Kugel has this seal. The fluid inlet ports on the cap (that you connect to the remote reservoir) let the fluid enter from above the accordion.

I don't see how that's going to work. Take a look HERE. Is this anything like what you're using, or in need of?

The accordion seal needs to be in the remote reservoir- the uppermost part of the system. The MC would then become the bottom part of the two-part system, and no longer needs the accordion seal.