Brake reservoir cap?

[neilbardsley]

When pressure bleeding my brakes. I temporarily misplaced the cap on my bleeder so I put the cap from my brake reservoir on the bleeder but it couldn't hold any pressure? Should I be worried? I'm guessing the pressure in the reservoir, under braking, isn't high.

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[Nine One One]

Is there not a hole on the reservoir cap, but not on the bleeder, hence that is why it can not pressurise.

[KS]

There is no pressure in the reservoir under normal use, so the cap is only designed to stay put and keep it from leaking. As per the above post, there is a breather hole (either in the cap itself, or in the form of a small tube/pipe in the top of the reservoir).

[neilbardsley]

Sry I don't understand. I didn't think either cap should have a hole? The normal pressure bleeder filler cap hold pressure very well but when I swapped the reservoir cap in place of it, it couldn't hold pressure.

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[KS]

They're doing totally different jobs - the pressure bleeder pressurises the reservoir to push the fluid through the system. The reservoir cap has a breather hole to allow for fluctuations in fluid level. The reservoir is not pressurised, simple.

[neilbardsley]

They're doing totally different jobs - the pressure bleeder pressurises the reservoir to push the fluid through the system. The reservoir cap has a breather hole to allow for fluctuations in fluid level. The reservoir is not pressurised, simple.

Thank you. That is what I didn't understand

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