Ever since I changed the master cylinder and brake booster on my 1990 civic my brakes will lock up. The car runs perfectly at first. But with every stop my brakes become harder to depress. Eventually the brakes will fail to retract and slow the car. I am trying to repair the system... using haynes manual as a guide, but I can't find out what is wrong... HELP

Possibilities:

. Pushrod clearance adjustment--before installing the master cylinder, check and adjust the pushrod clearance (0-0.4 mm or 0-0.02 in.). Adjust the pushrod length when the booster is removed to 116 mm +/- 0.5 mm.

. Brake pedal height adjustment. Standard pedal height, with floor mat removed, for a manual transmission is 160 mm or 6.3 in. minimum.

. Caliper problems--if the brake fluid has not been regularly changed, caliper corrosion could be preventing the calipers from retracting. Similarly, caliper pins should be lubricated with silicone grease, to allow the calipers to "float." Pull a wheel and see how the caliper and caliper pins are functioning.

. Brake fluid--properly flush and bleed brake system.

My guess is that the brake system has not been well maintained and calipers and wheel cylinders are binding. If so, they would need to be rebuilt or replaced. Pads and shoes may be so worn that the calipers/wheel cylinders are at the end of their effective range and are binding. The problem can be compounded further, if the discs and drums have ever been turned. This forces the pistons to extend even further. Standard front disc thickness is 9.0 mm and max. refinishing limit is 8.0 mm. Standard inside drum diameter is 180 mm and the service limit is 181 mm for most Civics of this era with manual transmission.