316 PC PASSENGER-BRAKE EQUIPMENT 



LUBRICATING THE CONTROL VALVE 



Equalizing Portion. The equalizing portions of the control 

 valve should be lubricated with a high grade of dry graphite 

 (not flake graphite) of the highest obtainable fineness and 

 purity. Oil should not be used for this purpose. A free use of 

 oil should be made in "rubbing in" the bearing surfaces of the 

 equalizing portion, but all oil, gum, or grease should be thor- 

 oughly removed from the slide valves and seats before lubrica- 

 ting them, as follows: Rub graphite on the face of the slide 

 valves and their seats, on the face of the graduating valves and 

 their seats, and on the upper portions of the bushings where 

 the slide-valve springs bear. The graphite should be applied 

 in such a way as to fill in the pores of the brass and leave a very 

 thin, light coating on the seats. After lubricating the parts, 

 care should be taken not to touch them with the hands, as 

 moisture tends to remove the thin coating of graphite and thus 

 destroy the lubrication. 



The graphite is best applied with a stick about 8 in. long, 

 to one end of which is glued a small pad of chamois skin. The 

 skin on the end of the stick is dipped in the graphite, and the 

 graphite is rubbed on the surfaces to be lubricated. A few 

 light blows of the chamois on the valve seats will leave sufficient 

 loose graphite on them. 



After the pistons and slide valves are replaced in the equal- 

 izing portion, they should be moved to release position so that 

 a little oil may be rubbed on the piston bushings; the pistons 

 should then be moved back and forth several times to make 

 sure that the oil is evenly distributed on the bushing. Only 

 a thin coating of oil should be used, and it should be well 

 rubbed in so that there will be no free oil left on the parts 

 after they have been oiled. 



Application Portion. The application valve and seat and 

 the exhaust valve and seat of the application portion of the 

 control valve should be cleaned; then they should be rubbed 

 in with oil, which should be thoroughly removed; and finally, 

 they should be lubricated with graphite in the same manner 

 as the slide valve and seats of the equalizing portion. During 

 the time that the piston is removed, the cylinder should be 



