DISTRIBUTION SYSTEMS - PRIMARY HYDRAULIC POWER SYSTEM Gear Pumps 1. Fan Drive Output (rear pump) 2. Spreader and Rotary Air Screen Output (center pump) 3. Control Pressure Output (front pump) 4. Supply From PTO Gearbox, (for pump 3) 5. Supply From Hydraulic Reservoir, (for pumps 1 and 2) The gear pump assembly is mounted in the PTO gearbox and incorporates three separate gear pumps. -- The Control Pressure pump, (pump 3, nearest to the drive shaft), is supplied oil from the PTO gearbox and all of its flow is returned to the PTO gearbox. See specification page.
-- The Spreader/Rotary Air Screen Drive pump is supplied oil from the hydraulic reservoir and returns all of its flow back to the reservoir. See specification page. -- The Fan Drive pump is supplied oil from the hydraulic reservoir and returns all of its flow back to the reservoir. See specification page. 9 NOTE: If the seal was to leak between the front and center pumps oil could transfer between reservoirs. A.10.A / 13