Curso paus

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Series 51

Bent Axis Variable Motors Repair Instructions

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q When Series 51 units are used in vehicular hydrostatic drive systems, the loss of hydrostatic driveline power in any mode (forward, reverse, or “neutral” mode) of operation may cause a loss of hydrostatic braking capacity. A braking system, redundant to the hydrostatic transmission must, therefore, be provided which isadequate to stop and hold the system should the condition develop. q Certain service procedures may require the vehicle/machine to be disabled (wheels raised off the ground, work function disconnected, etc.) while performing them in order to prevent injury to the technician and bystanders.

Series 51 MV Repair Instructions
Genuine Parts Original Ersatzteile

BLN-10044 Page 2

August 30, 1993Safety Precautions
q Use caution when dealing with hydraulic fluid under pressure. Escaping hydraulic fluid under pressure can have sufficient force to penetrate your skin causing serious injury. This fluid may also be hot enough to burn. Serious infection or reactions can develop if proper medical treatment is not administered immediately. q Some cleaning solvents are flammable. To avoidpossible fire, do not use cleaning solvents in an area where a source of ignition may be present.

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Series 51 MV Repair Instructions
Genuine Parts Original Ersatzteile

BLN-10044 Page 3

August 30, 1993

Major Repair Instructions — General
CAUTION — DISCLAIMER OF LIABILITY These repair instructions are provided for technicians who have been trained by Sauer-Sundstrand in the repairof Sauer-Sundstrand Series 51 motors. Sauer-Sundstrand recommends that any repairs be performed by Sauer-Sundstrand trained technicians. Sauer-Sundstrand expressly disclaims any liability for workmanship related failures resulting from repairs performed by any person using these instructions. The procedures on the following pages are for the complete disassembly and reassembly (Major Repair) ofthe Series 51 Variable Displacement Motors. Cleanliness is a primary means of assuring satisfactory hydraulic motor life, on either new or repaired units. Cleaning parts by using a clean solvent wash and air drying is usually adequate. As with any precision equipment, all parts must be kept free of foreign materials and chemicals. Protect all exposed sealing surfaces and open cavities from damageand foreign material. During the assembly of the Series 51 variable motor, all surfaces which have relative motion between parts should be coated with a film of clean hydraulic oil. This will assure that these surfaces will be lubricated during start-up. It is recommended that all O-rings and gaskets be replaced. Lightly lubricate all O-rings with clean petroleum jelly prior to assembly. All gasketsealing surfaces must be cleaned prior to installing new gaskets. Refer to the Series 51 Bent Axis Variable Displacement Motors Service Manual for further information.

Multi-function Block Control (Hydraulic Proportional)

Pressure Compensator Override

Minimum Displacement Limiter Valve Segment Bearing Plate Tapered Roller Bearings Motor Output Shaft

4-Way Valve and Sleeve

ControlSprings Synchronizing Shaft and Rollers

Piston

End Cap Servo Piston Cylinder

Housing Charge Pressure Relief Valve Minimum Angle Servo Cover
Copyright 1993, Sauer-Sundstrand Company. All rights reserved. Contents subject to change. Printed in U.S.A. 0893H

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Series 51 MV Repair Instructions
Genuine Parts Original Ersatzteile

BLN-10044 Page 4

August 30, 1993

Major RepairInstructions — Disassembly 1
Remove the control and multi-function block (if installed), 4-way valve spool and sleeve (if installed), control springs (if installed), and minimum angle servo cover from the motor. Refer to the Series 51 Service Manual for details. Remove the screws (items G32 and G34) retaining the end cap assembly to the motor housing. Remove the end cap assembly, gasket (item...