GEAR PUMP

HYDRAULIC

the pump drive gear which meshes with the camshaft

GENERAL

gear, The pump drive gear also drives the engine

governor.

The hydraulic system consists of the following

assemblies: Hydraulic tank, full-flow filter, system pump,

When the circuit selected has received the required

manual control valve, tilt cylinder, hoist cylinder. (Fig.

amount of oil, or the pressure within the circuit becomes

too high, excess oil is by passed by a relief valve, which

is located in the manual control valve.

The hoist cylinder assembly, which includes the lowering

control valve, and tilt cylinder assembly,/are discussed

GEAR PUMP

in the Hoist Section.

Although procedures for several hydraulic components

A. GENERAL

are outlined in other sections, it is important that these

components be considered when troubleshooting the

This pump is located on the left side of the engine,

entire hydraulic system.

under the engine manifold and attached to the timing

gear housing. (Fig. 3)

A positive displacement pump draws oil from the

hydraulic tank and delivers it to the manual control

Oil is prevented from by-passing the body and end

valve. This model is equipped with a gear type pump.

cover by a neoprene gasket between the components.

A replaceable shaft seal is pressed into the front cover.

Pump mounting utilizes an adapter (Fig. 2) which is

Communication

machined to hold the pump in alignment with the driving

gear. Contained within the adapter is a ball bearing and

Figure 1.

B-145