Reader Question I have a 86 VW scirocco 1.8 litre 8 valve I replaced the master cylinder, flex lines to the front calipers, calipers and rotors. Now my front brakes will not release. The master cylinder cap seems like it gets very tight as if there allot of pressure building up. Any ideas what would cause this. Any advice is appreciated.
I am not familiar with this vehicle model. If you did not have this problem before you replaced these parts…I would suspect either you were given the wrong parts, and you should compare them closely to the old parts, or there is a problem with the installation of these parts.
Unscrew the front bleeder screws on the calipers one at a time and see if there is pressure at the caliper. If the fluid squirts out the bleeder screw at the caliper, I would double check your installation then try bleeding the entire system again starting with the master cylinder.
Or best yet, gravity bleed the system, open each bleeder screw and let gravity slowly suck out the fluid/air. Just make sure you keep the master cylinder full of fluid. This can take an hour or so.
If this is the problem you were trying to solve with the parts you replaced…then I would look to see if there is a separate brake proportioning valve, and either try to bleed the valve or replace it. Follow the metal brake lines from the master cylinder to the rear brakes, and you should find the valve.