Gradall LOED 534A Service Manual - Manual (Page 35)

FIELD TESTING PROCEDURES
To set main relief valve pressure, install a pressure gauge in the inlet line and set pressure as follows
R e m o v e a c o r n n u t a n d l o o s e n j a m n u t .
Back off pilot adjustment screw and reset so that pilot adjustment screw just seats against pilot
p o p p e t .
R u n e n g i n e a t n o r m a l o p e r a t i n g s p e e d .
Operate one plunger of the control valve at the extreme position until a pressure reading is observed.
R e s e t a d j u s t m e n t s c r e w u n t i l d e s i r e d p r e s s u r e o b t a i n e d .
Holding adjustment screw at this setting, tighten jam nut and install acorn nut.
Retest to check pressure setting.
NOTE: THE ABOVE SETTING WILL PRODUCE A RELATIVELY CONSTANT RELIEF VALVE SETTING ACROSS
FULL ENGINE RPM.
To set pressure on the Service Port Relief Valve, install a good pressure gauge in the line which is in com-
munication with the Service Port Relief Valve. Apply a load to reach the set pressure of the Service Port
R e l i e f u n i t . T h e n p r o c e e d a s o u t l i n e d f o r F i g . 29 ( S e e A b o v e ) .
NOTE: THE VOID CONTROL FEATURE IS DESIGNED TO OPERATE WHENEVER THE CYLINDER PORT PRES-
SURE IS LOWER THAN THE RESERVOIR PRESSURE AND IS NOT ADJUSTABLE.
Pilot Operated - Sleeve Type Main Relief Valve
Cartridge Type - Main Relief Valve (identical in design port relief valve).
35
FIGURE 29
FIGURE 30