Classic/Antique Car Repair: mg midget 79, flex lines, dot 4

Question
front wheels are locked up. I had the master changed. I drove it 10 minutes and they started to drag again. to a halt. running out of solutions with the local mechanic as well as money. Please help    Mike

Answer
Hi Mike,
You need to do a couple of simple tests.
While you have the front wheels locked up just loosen a caliper bleeder valve. If the wheels do NOT free up you have a caliper problem. If they do free up you need to do more tests. Close the bleeder valve and drive the car again to get the brakes locked again. Now check to see that the brake pedal is a little loose meaning it should have a little free play. If it does NOT have any free play, check first for a sticking pedal. If the pedal is not sticking but the pedal does not have any free play loosen the mounting bolts holding the master cylinder about a quarter way out then check to see if the front wheels are free. If they are still locked up do one more test. Loosen the line fitting for the front brakes going into the master cylinder and check to see if the front brakes get free. If they do free up you have a bad master cylinder, If they do not free up you have either a pinched brake line or your caliper flex lines are swelled shut. If your flex lines are swelled shut or you have a bad master cylinder you need to check that DOT 3 brake fluid was ever used in this car. You must use DOT 4 or if it is a restored car and not driven much you can use DOT 5 fluid. Never DOT 3 though.
Driving the car is heating up the brake fluid because the brakes are dragging. Normally when your foot is off of the pedal the fluid can expand and go through the master into the reservoir and no pressure is built up. In your case the brakes are dragging and the fluid can not return to the reservoir for one of the above reasons.
Let me know what you find.
Howard