Great Plains Case Drain & Motor Return Tractor Connection Guide - Manual (Page 3)

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CDMR 08/27/10
Great Plains Manufacturing reserves the right to make changes or to add improvements to this guide at any time without notice or obligation.
Explanation
Early production YP Planters and Air Drills were not manufactured with fan motors that utuilized a
case drain connection. If there are only two lines connected to the fan motor, then the case drain
connection is not utilized. If there are three hoses connected to the fan motor, then case drain is
utilized.
The purpose of this guide is to show the port locations for connecting case drain and motor return
for Great Plains YP Planters and Air Drills that utilize continuous flow fan motors. The information
obtained for this guide was taken directly from the tractor manufacturer’s information that is
available on-line and through tractor dealers.
Since tractor equipment and options vary, the connections shown in
this guide must be verified through the tractor manufacturer or dealer
to prevent damage to the tractor and implement hydraulic systems.
Great Plains continuous flow fan motors require case drain and motor return lines to protect
the motor during use. The case drain line must be connected first, then connect motor return
line before connecting the pressure line. Failure to do so can cause damage to the motor
seals. When disconnecting, always disconnect pressure, then motor return, and case drain
last.
ALWAYS Connect ALWAYS Disconnect
Case Drain First Fan Pressure First
Motor Return Second Motor Return Second
Fan Pressure Last Case Drain Last
Case Drain
This connection is required to carry the motor case internal leakage directly to the
tractor hydraulic reservoir (sump) with zero pressure. This oil serves to lubricate and
cool motor components not directly exposed to the working oil. Great Plains supplies a
3/8” body size ISO 16028 zero pressure flat face case drain male coupler on a 1/4”
hydraulic hose for the fan case drain line. It is normal to have seepage from this fitting
when disconnected from the tractor to protect the motor seals from thermal expansion.
If the tractor is not equipped with a female flat face case drain coupler, then it must be
sourced through a tractor dealer or hydraulic supplier.
0.72”
0.26”
3/4-16
FORB
0.777” 0.5”
Great Plains
P/N 841-099C
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NOTE: Dimensions are for reference only. Not exact size.