Brake fluid seeped out of filler cap when changing brakes..?

[battmiceter]

When I pushed the brake calipers back,

brake fluid leaked from the filler cap even thow it was tightened up!

does this mean I have bust it the reservoir?

[zollaf]

as the level drops as the brakes wear, air must be able to get in or a vacuum would form which would be no good. air must also be able to escape as the fluid heats up and expands. basically there will be a vent hole in the cap which fluid will go through if forced, so no, you havn't broken anything. however, next time, loosen the bleed nipple on the caliper you are pushing back and use some tube to flow the fluid into a container, rather than pushing it back through the abs pump and master cylinder, which can often end in tears.

[Doctle Odd]

You could have been unlucky and ruined the ABS pump an old piece of vacuum pipe on the nipple is all you need. Makes them easier to push back too

[battmiceter]

Thanks,

What is the correct procedure, do I loosen the bleed nipple then push the pad back?

[Doctle Odd]

Yes loosen 3/4 turn. An old piece of vacuum pipe or similar attached to the bleed nipple and the other end into an old bottle. Never re-use old brake fluid and replace it every 2 years