slow front o/s puncture

had a slow o/s front puncture so out came the car pump to get  its correct psi, and then off to get it fixed.  but when checking the n/s rear wheel the brass outer thread on the valve had broke just leaving the inner valve sticking out. off to a tyre place asap, well the guys where great and fitted a new valve on the rear wheel and balanced, along with taking the front tyre off and checking tyre wall and wheel rim but found no problems? so new valve fitted and tyre replaced along with both front wheels being balanced.  total cost £15  what a great deal and a good job done as all wheels are now fine.