Checking Pump Flow Rate; Fig. 5-24: Checking Hydraulic Pump Flow Rate - JLG Lull 1044C-54 II Series Service Manual

Supply, Pressure, and Return Hydraulics

Checking Pump Flow Rate

5-38
3
2
1
# Description
1 Return Filter Housing
2 Hex Cap
3 Hydraulic Tester

Fig. 5-24: Checking Hydraulic Pump Flow Rate

(Ref. Fig. 5-24) If the pump(s) is suspected of delivering below rated
capacity, use the following procedure to check pump flow rate:
1. Lower boom to the ground, apply parking brake and stop engine.
Release all hydraulic pressure in the system (See warning and
procedure under "General Hydraulic Maintenance Practices" on
page 5-3 of this section).
2. Loosen and remove pressure line hose (Item 6) from pressure port of
pump (Item 5) to be tested.
3. Loosen and remove hex cap (Item 2) from top of return filter housing
(Item 1).
4. Assemble a hydraulic tester (Item 3) in a test loop between the pump
and return filter. Use hydraulic hose (Item 4) with a minimum burst
pressure rating of 12,000 psi. Hose end fittings for the pump and return
filter must be 1 1/16-12 JIC (37°) female.
5. Determine the system's maximum rated pressure (which is the
specified-relief setting for boom hoist and extend control valve). See
Fluid Pressures under "Specifications" for your model forklift in section
2.
4
6
# Description
4 Test Loop Hose (2)
5 Hydraulic Pump
6 Pressure Hose (2)
4
5
6
31200079