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Q: Brakes won't let go after changeing main brake cylinder.

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OK, I changed the main cylinder (new part) because it went straight to the floor without brake power. Workshop said it was wrong fluid on the system. I changed all brake fluid and replaced with Dot +4.

After changing the cylinder the brakes locked. They do brake normally but does not let completly go, and my disks get hot. It is not impossible to drive, but the car struggles in 5th gear, and wont roll freely in gently downhill. However, the problem is solved by pulling the pedal gently outwards and by doing so after each braking it is possible to drive. This happends on all 4 wheels.

My trobleshooting in order: -Adjusted the pin rod in the brake booster inwards, to release pressure (if there) on to brake cylinder. -Adjusted the pedal inwards and outwards -Changed the brake booster (used part) -Replaced the vacuum hose to the booster -Changed all brake hoses -Disconnected ABS-fuses -Removed the brake light switch

And the problem is still there, and the brand workshop can't help me.

My car has 230000 miles.
My car has a manual transmission.

Rule out obvious causes such as sticking calipers. If you are positive that the caliper pistons are free and the pins in the torque plate are free as well, measure the brake line pressure at each wheel to determine both if the pressures are correct (and proportioning valve is working) and if pressure releases. If pressure is not releasing, see if failure to release is in one or both circuits (the brake system is sectionalized for safety). If the problem is global, the master cylinder is stuck. If this does not resolve it, request a brake system diagnostic - pressure testing and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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