Land Pride | Table of Contents |
Section 1: Assembly and
| Pressure Line |
Inlet Valve of | Quick Coupler |
Backhoe Valve |
|
Press.
Tank
(Male) (Female)
Circuit when Backhoe
is removed
(Male)
(Female)
Return Port
(Female)
Power Beyond Port
Quick Coupler
Oil Reservoir
(Backhoe or
Tractor Sump)
Quick Coupler
(Male)
Pump
(Rear, Front or Tractor)
Suction Filter
(Backhoe, Tractor)
Valve Return Hose
Tractor Loader Valve
Return Outlet
19548
Inlet of Valve
Backhoe Independent Hydraulic Systems
Figure
Testing Procedure for
Hydraulic Circuits
Identification of terminology:
1.PSI (Pounds per square
2.GPM (Gallons per
A glycerin filled hydraulic pressure gauge (located on the right hand side of the valve) is factory installed on your Land Pride Backhoe for your convenience in testing and diagnosing any problem that may arise in the backhoe hydraulic system.
The gauge indicates only PSI, but with proper use, one can diagnose almost any hydraulic problem in a backhoe’s hydraulic system. The first thing to remember is the backhoe hydraulic valve is made of six individual valves, each doing a single function. The only thing that is common to the valve bank is the hydraulic valve and the master relief valve.
Testing Open Center System
Check the pump and master relief: If a problem exists on all hydraulic circuits, the pump or master relief usually causes it. To check these, operate the tractor at a very
low speed while actuating the stabilizer control in the UP position until the cylinder is entirely collapsed, continue holding the control lever and read the PSI on the gauge. Next, speed the tractor up. If the PSI increases as the speed increases, this indicates a worn pump. If the PSI remains steady, but less than 2250 lbs, then the backhoe’s master relief is set too low (See HOW TO SET PRESSURE ON MAIN RELIEF VALVE section).
!CAUTION!
Never attempt to adjust any relief valve without a gauge in a pressure line.
Checking a Single Circuit
If the power or speed goes down on one function the problem is in that valve section, circuit relief, cylinder, or a restriction in the hoses (The boom and stick are restricted to prevent sudden drop). To check the individual circuit, move the cylinder to the end of its stroke, and continue holding the valve, then take a pressure reading and compare the readings, they should be the same. If they are not the same it could be a faulty circuit relief. Circuit reliefs are on the down stroke of the
7/14/08 | BH3512 Backhoes | 11 |
