brakes

[cisco68]

front brake calipers, brand new, just installed. they won't fully release once applied. what can cause this condition? master cylinder? booster? any thoughts appreciated.

[alternativez2003]

before the caliper replacement? Do you mean the wheels will not spin freely once the pedal is released? I assume they are properly installed with the bleeders at the top of the caliper. How are the rear cylinders doing? Does the master cylinder piston (not just the pedal) return completely when the pedal is released? Just off the top of my head I would look at a couple of things if it is both sides not releasing. The master cylinder may be sticking, and a good cleaning might clear it up, or the vacumn one-way valve on the booster might be stuck or clogged. Otherwise, if your rear brakes are ok, bleed again, and bleed the rear also for good measure, going around the car from longest line to shortest a couple of times. If there is air in the lines you generally would feel the squishy pedal, but just a small amount of air could compress without being felt in the pedal and then keep the pressure one the pistons when the pedal is released. You've probably already considered or done all this, but I don't know what you already know. A new master cylinder is very$, and the rebuild kit is very$ also, but opening it up, cleaning and reassembling is not a big deal. These are the basics. Good luck.

[cisco68]

thanks for the thoughts. both front calipers are new. the pedal is firm and returns to correct position when released. the calipers won't release once applied. how do i tell if the master cylinder itself comes back to the correct position? how do i check the one way valve on the booster? any links to possible diagrams? thanks again.