Brake apply pressures-Service versus spring?

[Low Class]

Does a full service brake application deliver full system pressure to the diaphrams?

What about the spring brake?  I would guess that it would equate to the pressure that it begins to release, which would be what__40-50 psi?

Some time ago, I read a good article about brakes that was written by RJL.  I can't find it.  RJ, is it still available?  Link?

[bevans6]

A normal spring brake application is about equal to 60 psi.  If your brake system is working properly a full brake application at the pedal should send 100% of available air pressure to the chambers.

Brian