MacDon 871 Combine Adapter - Manual (Page 23)

23
MAINTENANCE/SERVICE
HYDRAULIC SYSTEM (continued)
Flow Control Relief Pressure
A possible cause of insufficient draper speed is
low relief pressure.
To check relief pressure:
1. Attach a 5000 psi (34.5 MPa) pressure gauge
in gauge port (GP) of valve block.
2. Install a needle valve between orange colour
coded male coupler on adapter and orange
colour coded female coupler on header.
3. Set flow control knob to number 6 on dial.
4. Run combine engine at operating speed.
5. Engage header drive.
6. Close needle valve until flow stops. Pressure
reading should be 2850 psi (19.7 MPa).
WARNING: To avoid bodily injury
from bursting hoses and/or
exploding components, do not
exceed 3100 psi pressure (21.4 MPa). Do not
continue closing needle valve if pressure
exceeds 3100 psi (21.4 MPa).
If relief pressure requires adjustment:
1. Loosen jam nut (C).
2. Turn relief screw until relief pressure is correct.
3. Tighten jam nut.
FLOW CONTROL RELIEF ADJUSTMENT
GP
C
COMBINE ADAPTER HYDRAULIC SCHEMATIC