Oshkosh JLG 1500SJ, Руководство по обслуживанию и ремонту

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SECTION 5 - BASIC HYDRAULIC INFORMATION & HYDRAULIC SCHEMATICS
3121262 – JLG Lift – 5-117
5.6 PRESSURE SETTING PROCEDURE
Cold temperatures have a significant impact on pressure read-
ings. JLG Industries Inc. recommends operating the machine
until the hydraulic system has warmed to normal operating
temperatures prior to checking pressures. JLG Industries Inc.
also recommends the use of a calibrated gauge. Pressure read-
ings are acceptable if they are within ± 5% of specified pres-
sures.
To ensure all pressures are set correctly, the following proce-
dures must be followed in order.
1. All applicable steps in Section 5.9, Drive & Function
Pump Start Up Procedures must be followed.
2. Set up of the function pump.
3. Adjustments made at the main valve bank.
4. Adjustments made at the platform valve.
5. Adjustments made at the jib valve.
Set Up of the Function Pump
HIGH PRESSURE RELIEF
1. Install a high pressure gauge at the MP port of the main
valve block.
2. Using a screwdriver, remove the Din connector from the
lift down coil.
3. Activate lift down. The gauge should read 3400 psi
(234.4 bar).
4. To make an adjustment to this pressure on a Rexroth
pump, go to the engine compartment and locate the
function pump which is the back pump. The high pres-
sure relief adjustment is the adjustment closest to the
pump. Using a 17 mm wrench, remove the cover nut. Be
careful not to lose the o-ring washer inside the cover
nut. Loosen the jam nut at the setscrew with the 17 mm
wrench. Using a 3 mm allen wrench, adjust clockwise to
increase, or counterclockwise to decrease pressure.
To make an adjustment to this pressure on a Sauer
pump, loosen the 4 mm setscrew towards the engine.
Using a 6 mm allen wrench, turn clockwise to increase
pressure and counterclockwise to decrease pressure.
5. After adjusting the pressure, tighten the jam nut and the
cover nut if applicable. This is the
maximum relief pres-
sure for all the functions governed by this pump.
STAND BY PRESSURE OR LOW PRESSURE RELIEF
1. Install a low pressure gauge at port MP of the main valve
block capable of accurately reading 300 psi (20.6 bar).
2. Start the engine, the gauge should read 300 psi (20.6
bar).
REXROTH PUMP
SAUER PUMP