Only Ninjas bleed?

[Ericthejet]

Changing out the front brake fluid while I wait for my forks to get back from the shop.

I have a nice manual and it seems simple enough.
My question is do I need to have the reservoir cap in place while bleeding?

I understand one must keep air from getting into the line and once I start to push out the old I will need to add as I go.

Thanks.

[Cerberus]

the reservoir cap prevents dirt from falling into the reservoir and helps minimize the hygroscopic behavior of the brake fluid. it has nothing to do with letting air into the system.

[Ericthejet]

So while I'm bleeding the lines the cap can be off?

[Paul_E_D]

yes, it needs to be off so you can top it up as you go.

[Cerberus]

it will have to be off to allow you to add fluid to replace what you are bleeding out of the system. never let the reservoir fluid level get low enough to suck an air bubble or you'll undo all you've done and have to start over.

that said, i would leave the cap on (if only resting in place) to prevent any crap from falling in, as well as avoiding the little geyser of brake fluid that happens on some master cylinders when you squeeze the brake level