[MR_GRUMPY]

Just get a new Presta only head, to replace that presta/schrader head.

90 degree heads are for disc wheels. (the pop off rather easily)

You can buy this stuff most everywhere

http://www.westernbikeworks.com/search/pump-parts-and-accessories

http://www.excelsports.com/main.asp?page=7&major=3&minor=9

http://www.coloradocyclist.com/product/display/70580/