Description And Operation; Power Steering Return Line; Power Flow And Pressure - Jeep cherokee 2000 Service Manual

19 - 6 STEERING
DESCRIPTION AND OPERATION (Continued)

POWER STEERING RETURN LINE

DESCRIPTION
Power steering return line is a hose which is
clamped at the pump and the gear.
OPERATION
Power steering return line, is used to transfer low
pressure power steering fluid, from the power steer-
ing gear to the power steering pump.
DIAGNOSIS AND TESTING

POWER FLOW AND PRESSURE

The following procedure is used to test the opera-
tion of the power steering system on the vehicle. This
test will provide the gallons per minute (GPM) or
flow rate of the power steering pump along with the
maximum relief pressure. Perform test any time a
power steering system problem is present. This test
will determine if the power steering pump or power
steering gear is not functioning properly. The follow-
ing pressure and flow test is performed using Power
Steering Analyzer Tool Kit 6815 (Fig. 2) and Adapter
Kit 6893.
Fig. 2 Power Steering Analyzer
1 – TUBE
2 – ADAPTER FITTINGS
3 – ANALYZER
4 – GAUGE HOSE
FLOW AND PRESSURE TEST
(1) Check the power steering belt to ensure it is in
good condition and adjusted properly.
(2) Connect pressure gauge hose from the Power
Steering Analyzer to Tube 6865.
(3) Connect Adapter 6826 to Power Steering Ana-
lyzer test valve end.
(4) Disconnect high pressure hose at the pump.
Use a container for dripping fluid.
(5) Connect Tube 6865 to the pump hose fitting.
(6) Connect the power steering hose from the
steering gear to Adapter 6826.
(7) Open the test valve completely.
(8) Start engine and let idle long enough to circu-
late power steering fluid through flow/pressure test
gauge and to get air out of the fluid. Then shut off
engine.
(9) Check fluid level, add fluid as necessary. Start
engine again and let idle.
(10) Gauge should read below 862 kPa (125 psi), if
above, inspect the hoses for restrictions and repair as
necessary. The initial pressure reading should be in
the range of 345-552 kPa (50-80 psi).
(11) Increase the engine speed to 1500 RPM and
read the flow meter. The reading should be 2.4 - 2.8
GPM, if the reading is below this specification the
pump should be replaced.
CAUTION: The next step involves testing maximum
pump pressure output and flow control valve oper-
ation. Do not leave valve closed for more than three
seconds as the pump could be damaged.
(12) Close valve fully three times and record high-
est pressure indicated each time. All three read-
ings must be above specifications and within
345 kPa (50 psi) of each other.
• Pressures above specifications but not within
345 kPa (50 psi) of each other, replace pump.
• Pressures within 345 kPa (50 psi) of each other
but below specifications, replace pump.
(13) Open the test valve, turn steering wheel
extreme left and right positions against the stops.
Record the highest indicated pressure at each posi-
tion. Compare readings to specifications. If highest
output pressures are not the same against either
stop, the gear is leaking internally and must be
repaired.
CAUTION: Do not force the pump to operate
against the stops for more than 2 to 3 seconds at a
time because, pump damage will result.
PUMP SPECIFICATIONS
RELIEF
ENGINE
PRESSURE
9653 kPa
2.5L
(1400 psi)
9653 kPa
4.0L
(1400 psi)
FLOW RATE (GPM)
50
1500 RPM 2.4 - 2.8
GPM
XJ