renhod

1995 ce lti a4

I replaced the piston in the driver’s rear caliper. Paid attention to how it came apart. The piston fit, paid attention to how it went together. Bled the caliper. Got some bubbles maintained the fluid level in the reservoir. Got some more bubbles, then none. Now no bubbles and no pedal. Goes right to the floor with warning light. Hteres air some where? Abs pump?

drcook

You need to rebleed the entire system, starting with the right rear wheel (passenger side). Do rt rear, lt rear, rt front, lt front. Get yourself a rubber/plastic mallet. Tap the calipers before opening the bleeder. Banging the caliper will dislodge any air bubbles.

If you left the caliper/line drain while working on it, you most likely have an air bubble going to the right rear. Bleeding the entire system will clean it out and get any water contaminated fluid from the rest of the system. (brake fluid is hygroscopic and sucks water out of the air, even through the system)

renhod

thanks. that did it. after about 50 pumps got all air and old fluid out.

ctmccloskey

In the future you might try a "Phoenix Reverse Bleeding System". It is a hand pump that pushes the fluid from the caliper to the master cylinder. It is so much easier to push air up and out than to force it down out the bottom. I use this tool to flush my brakes every five years and it makes it a easy job on my C3 and the infamous 1988 C4 brake system.

This tool is the only one to ever get ALL the air out of my hydraulic clutch on my Chevy P/U. I have used my reverse bleeder on cars, RV's, motorcycles and even aircraft all with great success. The tool is not expensive and works wonders.