landrover Workshop Repair Guides

Land Rover Workshop Service and Repair Manuals

Operation > < Power Assisted Steering (PAS) Pump and Reservoir
Page 224
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STEERING

DESCRIPTION AND OPERATION

57-21

Td6 PAS Pump and Reservoir

Cap
Reservoir
Rear engine mounting bracket

Pump assembly
Pulley
Front engine mounting bracket

The Td6 PAS pump comprises a body which houses the internal components of the pump. A pressure relief valve, 
which also incorporates a flow control valve, is installed in the housing. The pressure relief valve limits the maximum 
pressure to between 120 and 127 bar (1740 and 1840 lbf/in

2

). The flow control valve limits the maximum flow to 

between 9.75 and 11.25 l/min (2.14 and 2.47 UK gal/min).

A shaft runs longitudinally through the pump. One end of the shaft has a drive flange which accepts the drive pulley. 
The opposite end is closed by a cover. The shaft runs in bearings located in the body. Oil seals at each end of the 
shaft prevent leakage.

An oval cam ring is located in the body. Ten vanes are housed in a carrier and rotate within the cam ring. The carrier 
is mounted in the centre of the shaft and receives positive drive from the shaft via a drive pin. The carrier is seated 
against an end plate which is located in the cover. The front of the carrier is covered by a port plate which is located 
against a seal plate in the body. The port plate controls the fluid flow into and out of the vanes during their cycle.

The fluid reservoir used on the Td6 model is mounted integral with the pump. The fluid supply to the pump is direct 
from a connection to the housing and the return is via a hose connection.

Operation > < Power Assisted Steering (PAS) Pump and Reservoir