215676
426
Revision A
Pressure Compensator Valve
The pressure compensator valve protects the header drive pumps from overheating under very heavy loads.
When the operating pressure reaches the absolute pressure limit setting (refer to Table
for hydraulic
pressure setting) the compensator valve in the pump is activated and the header drive will slow down to avoid overheating
the drive pumps. When this occurs, reduce the windrower
’
s ground speed to reduce the hydraulic system pressure.
NOTE:
An optional pressure sensor is available which monitors the knife or reel drive hydraulic pressure. This sensor will cause the
cab display module (CDM) to emit a warning tone if it detects that the hydraulic system pressure has reached a preset
limit. The system pressure limit can be configured using the CDM. For information on the pressure sensor kit, refer to
. The warning tone is only heard if the pressure sensor is installed and enabled.
NOTE:
The CDM emitting a warning tone is normal when the operating pressure is close to the compensator valve
’
s pressure
setting.
Table 5.3 Header Hydraulic Pressures
Header
Model
Application/System
Windrower Absolute Pressure
Limit Setting
kPa (psi)
Suggested Overload Warning Setting
kPa (psi)
R/R1 Series
Disc pressure
28,958 (4200)
27,579 (4000)
D/D1 Series
Reel/draper pressure
22,063 (3200)
20,684 (3000)
A Series
Knife/conditioner
pressure
28,958 (4200)
27,579 (4000)
If lift or drive capacity problems occur, the pressure compensator valve may require adjusting. Contact your MacDon Dealer
for assistance.
Flow Control Blocks
Two hydraulic valve blocks equipped with multiple cartridges are used for various windrower functions The flow control
blocks are regulated by the windrower control module (WCM), according to inputs from the Operator. The valve blocks are
located behind the left cab-forward platform.
1000864
Figure 5.194: Hydraulic Valve Blocks
The valve blocks do not require any scheduled maintenance
other than to check for leaking fittings or loose electrical
connections. If service is required, contact your MacDon Dealer.
