....you replace the valve the fittings broke off of?
What broke fittings anyway? Not a regular point of failure...
You should never get any air leak when brake pedal is pushed from ANY place in system. The air is probably coming out of the exhaust port on the dash valve.
It sounds from your post that the relay valve is plumbed wrong. The line from push in dash parking valve appears to be plumbed into the supply circuit of the "new" valve.
Easy way to check is to remove the smallest diameter line at the brake valve you just replaced/repaired. If you're lucky enough that there color coded, it's probably the yellow line....3/8 in diameter.
If Any air come out of the fitting you just removed line from, the valve is plumbed incorrectly. These valve's have several unused ports the have the be plugged off, ...if your guy didn't plug the same ports as the old one, it's a issue.
All brake valve's have to have a supply, delivery and exhaust port, as well as a brake relay valve will have a control port (line from dash valve)
If a supply is plumbed into a delivery side it will back feed air to dash valve.
As twinboat posted, a chamber diaphram will leak at the chamber,
A internal brake chamber leak will loose air at the brake relay valve exhaust port, parking brake supply air will leak back though the service hose from chamber to relay valve. Not the dash valve.
Sorry for the long explanation... hopefully this will get you pointed in right direction...
Google for a picture of a air brake parking/service valve.
btw, get a different repair guy. Someone who tells you that's normal to leak air isn't familiar with the system.
Please call a strong independent heavy truck shop or Local heavy truck dealer. This ain't no area to be sparing expense. ....
1999 American Eagle
ASE med/heavy certified technician
ASE advanced diesel certified