Gradall 534C-10 (2460-4129) Service Manual - Manual (Page 67)

Reason for Inching Check
Loss of control pressure can affect machine speed.
A low pressure gauge (1,000 PSI), hose, # 6 run tee and adapter should be teed into the Ps port on the drive
pump. Apply the park brake and run the engine at full throttle (2500-2700 RPM). The gauge reading should be
the same as in the previous control pressure test. Depress the brake pedal. The control pressure should start to
fall after one-half inch of pedal travel. This pressure should drop as the pedal travels farther and the service
brakes apply. The controlled linkage length should be 12-1/4 inches from the centerline of the yoke pins. The
lever arm position on the inching valve should set 1/8 inch off the pin as a starting point.
See Figure 16 and Figure 17.
Another check for the inching adjustment is to install a high pressure gauge (10,000 PSI), hose and adapter on
MA port on the drive pump. With the park brake on, move the shift lever to the forward position. At full throttle,
depress the inching/brake pedal slowly. When the roller on the pedal just touches the brake valve plunger, the
gauge should read 2,300 PSI +/- 100.
See Figure 15.
FIGURE 15
MAIN PUMP ASSEMBLY (SIDE VIEW)
VII. Inching
Form No. 29633 3/97 534C-9 & 534C-10
HYDROLASTIC DRIVE PERFORMANCE CHECKS MANUAL
15