hi there my name is don i will try to help you on this
your system is a bendix system
here is the diagram for that system

also can you please tell me what the problem is

copy and paste this into your browser

don

http://www.tamesisriver.com.ar/PDF/Compresores%20Bendix%20Tu-Flo.pdf

hi there thanks for that information

the brake system is like the one i sent you it is a fairly simple system
from what you have explained to me the safety valve they put in will be on the supply side

so the circuit you want to be concerned with is the green circuit

the valves you are going to need are the QR1C valve and the r12
the Qr1c kinde looks like the star ship enterprize

the r12 has a flat top with a t ontop and two airlines entering the t this valve controls your braking when you put your foot on the brake

the qrc1 valve is for the parking or emergency if you will

if you look on the brake pots you will see service side and emergency or supply side
the r 12 goes to the service side nd the ports from the qrc1 go to the supply or emergency side

check and verfy and get back to me or if you could take a picture and up load it that would be great
thanks
don

hi there the diagram is right under the first page all in color

i am back for a bit now
don