Bruce,
The brakes on M series trailers work exactly like and with the brakes on the
towing truck. the only reason they have a separate brake master cylinder is
to isolate the brake hydraulics for safety and to make hithc up simple (in
my opinion).
When you apply the brake pedal in the truck, air pressure is variably
applied to the hydraulics in both the truck and the trailer. The air
pressure is maintained int he trucka t a minimum of 90 psi. and usually
max's at 120 psi.
If you want to control the brakes on your trailer from your truck you are
going to need to manufacture an air brake valve that is functionally the
same as those used in true airbrake systems. When this vavle is opened, it
will apply variable pressure to the trailer brakes through airhoses. The
cocnept is fairly simple, but it will be completely custom. The good news
is that you don't have spring brakes, so you don't need 90 psi just to
release the parking brakes.
Good luck! Let us know how this works out. It is going to be functionally
similar to electric trailer brakes with a separate controller on the
steering column.
Joe Garrett
cell 425-344-1402
This archive was generated by hypermail 2b29 : Thu Jul 05 2001 - 00:40:37 PDT