A. Double check valve assembly

B. Air control line

C. Relay piston

D. Diaphragm assembly

E. Exhaust port

F. Atmospheric inlet

G. Atmospheric poppet

H. Air pressure poppet

J. Poppet return spring

K. Residual line check valve assembly

L. Brake pedal

M. Master cylinder

N. Diaphragm return spring

P. Hydraulic piston

Q. Piston return spring

R. Pushrod

S. Power piston

T. Trailer connection

Figure 7-61. - Air-hydraulic power cylinder (Air-Pak) during operation.