I did a complete replacement of all my brake parts (master cylinder, calipers, rotors & pads). I bled out all the old fluid and filled the system with new. Everything was great for about a week when suddenly there was no pedal. I found fluid dripping under the ABS pump. There was no obvious source of the leak. All the line fittings were tight. I had my son pump the pedal a couple of times and fluid squished out from a black plastic quarter sized plug directly under the left rear line connection. I removed the plug and there was a small brass fitting with a hole in the middle. When the pedal was pumped again, fluid sprayed out.
Can anyone tell me what is causing this leak?