leaking master brake cylinder

[surfingfreeman]

Hi All
My brake light just started coming on so i checked the brake fluid reservoir and i am losing brake fluid, at first i thought it was from a leaky rear caliper but turns out it is leaking at the junction where the front brake fluid reservoir feeder line meets the plastic rubber fitting on top of the master cylinder body, so what is replaceable that will stop the leak, in the Brooklands manual it looks like these are nipple type connectors which the the hoses connect to, are the fittings that go into the body of the master cylinder just a pressure fit? Do the fittings get loose over time and leak? Thanks for the help.
Mike

[So Cal Mark]

the nipples on the master cylinder are a push fit into a rubber grommet. Some of the aftermarket mc's have nipples that are held in by a spring retainer

[surfingfreeman]

thanks mark, so i can
replace the grommet and nipple and hose to try and stop the leak? thanks for the help.
Mike

[surfingfreeman]

Upon closer inspection one of the feeder lines from the reservoir that attaches to the master cylinder via a nipple and grommet connection had come unseated (at the grommet connection point), a good downward push and it snapped back into the cylinder body and now holds fluid nicely.

[So Cal Mark]

love to hear about those no-cost fixes!

[surfingfreeman]

im curious as to why/how the grommet came loose, i did recently put some new EBC greenstuff pads on which are truely excellent brake pads, we're talkin sticky good at stopping, my mechanic was very impressed with their braking performance. So my question is could it be that during part of the pad break-in process which includes carrying out a number of hard stops where you bring the car up to 60mph and firmly brake decelerating down to 10mph like 6 times in a row, is there any back-pressure at this grommet...................probably not.

[kmead]

The stopping causing it to pop up, not so much.

In order for him to replace the pads he had to push the pistons back in, which displaces fluid back through the MC and on into the reservoir. Could the reservoir have been already full since you are a careful and fastidious owner?

The vent in the cap may be blocked or it is so small that the back pressure built up and since the fluid is not particularly compressible, it had to go somewhere so it forced the nipple out of the top of the MC grommet and thus your leak.

A long shot for sure.

The other possibility is your mechanic inadvertently pulled on the hose during the brake change and it pulled out of the top of the MC.