sensing air shutoff valve 40 extends rearwardly from the top plate 51 it receives its connection to the pilot air duct 33 by a hose 53 from the manifold 50 the output 43 of the filling head source valve 44 is located on the bottom of the manifold 50 and is connected to the filling head 92 by a hose 96 the start valve 24 and blow down valve 28 are located on the same side of the manifold 50 in the prior art the start switch 22 and blow down switch 26 are rather complicated mechanisms the appropriate valve is actuated by a leaf spring that is pushed by a pivoting arm at the free end of the arm is a roller that is pushed by an external cam the reason for the roller is so that friction is kept to a minimum as the external cam slides by the various moving parts require regular maintenance to keep operating properly the present invention replaces each roller arm mechanism with a simple ball bearing 57 inside a collar 58 as can be seen in fig5 the front surface 56 of the manifold 50 is covered by a front plate 59 the front plate 59 includes a clearance hole 60 for the collar 58 the collar 58 is a short tube with a flange 62 at the inner end the inside diameter of the tube is slightly larger than the ball bearing 57 so that the ball bearing 57 slides easily within the tube an internal lip 64 at the outer end of the collar 58 as an inside diameter slightly smaller than the ball bearing 57 so that the ball bearing 57.