I unscrewed the bolt that sits below one of the brake lines leaving the master cyl (dont ask why), but in the process it took some threading out with it and it really wont go back in. It also seems like maybe a plunger or something has moved into place obstructing it from going in more than around half way.
Anyone got an explaination on what this bolt is all about? As for the moment I have no brakes until I can get something back in there..!

Last edited by Bug on Sun Mar 22, 2009 12:25 pm, edited 1 time in total.

That bolt as you put it sounds like the brake fail switch, is it plastic?

Never heard of one doing that but? the plunger is supposed to reset itself when the brake fluid is equalized. Your switch should have a little pin and a spring on it? Maybe someone before has bled the brakes and not taken that switch out first?

If it is not plastic then it may be a bolt that retains the primary piston of the master cylinder?

Not plastic, looking through the service manual there's actually a brake line coming from that point on some models, although mine is just a bolt. So that's three lines on some, 2 on mine.

I always seem to get punished when working on cars one way or another, undid it as part of a brake disc swap which was a surprisingly easy job but on a bit of bad advice I unscrewed this as a way to drain some fluid. Brakes 1 hour job.. fixing this 5 hours and counting..

now with pics! (that wasn't a bump a all)

Its Stuffed.

ABS equipped cars have this brass plug, front brakes are run from one main to the ABS block, then front brakes are fed from this.

Non ABS cars each front wheel run a brake line directly to the master cylinder.

either way, its under pressure.

easiest:
Replace it.
or
Mess around and helicoil it.
However this is best to do it while its off. There's nothing worse than alloy fragments in tiny pipes.