MG Car Repair: brakes, return spring, master cylinder

Question
wheel making squeal when going forward, brake pedal will not go down at all and feels as though brake is on. I am a novice, but this is a 1959 MGA, brake fluid or any other suggestions?

Answer
Hi Curtis,
Yes, the brakes are on. This is usually caused by either the rod between the brake pedal and the master cylinder is adjusted too long, the pedal is sticking and not returning or the piston in the master cylinder is sticking in the bore and not returning.

Normally when the brake pedal is released it returns with the help of a pedal return spring which retracts it and the rod away from the master cylinder piston which also has a spring on it to return it to the end of it's travel and hits a end plate that holds both the clutch and brake pistons in. The pedal return spring pulls the brake pedal rod away from the stopped piston just a small amount giving you a free play in the pedal of about an inch.

When the piston is allowed to retract all the way to the end plate a port is opened between the reservoir and the whole brake hydraulic system allowing any pressure to be exhausted into the reservoir.

Something on your car is holding that master cylinder piston in enough to close that port, thus maintaining pressure in the system.

Howard