Jeep Cherokee (XJ): Power steering pump

Power steering pump

DESCRIPTION

Hydraulic pressure for the power steering system is provided by a belt driven power steering pump (Fig. 1). The pump shaft has a pressed-on high strength plastic drive pulley that is belt driven by the crankshaft pulley. The reservoir is attached to the pump body with spring clips on the 4.0L engine.

A remote pump reservoir is used on the 2.5L engine mounted to the fan shroud. The power steering pump is connected to the steering gear by the pressure and return hoses.

OPERATION

The power steering pump is a constant flow rate and displacement, vane-type pump. The pump internal parts operate submerged in fluid. The flow control orifice is part of the high pressure line fitting.

The pressure relief valve inside the flow control valve limits the pump pressure.

NOTE: Power steering pumps have different pressure rates and are not interchangeable with other pumps.

Power steering pressure line

DESCRIPTION

The hose consists of two metal ends and rubber center section that contains a tuning cable.

Fig. 1 Pump With Integral Reservoir

1 - CAP
2 - FLUID RESERVOIR (TYPICAL)
3 - HIGH-PRESSURE FITTING
4 - DRIVE PULLEY
5 - PUMP BODY
6 - RESERVOIR CLIP

OPERATION

Power steering pressure line, is used to transfer high pressure power steering fluid, from the power steering pump to the power steering gear.

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 steering gear to the power steering pump.

Power flow and pressure

The following procedure is used to test the operation 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 following 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 Analyzer 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 circulate 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 operation.

Do not leave valve closed for more than three seconds as the pump could be damaged.

(12) Close valve fully three times and record highest pressure indicated each time. All three readings 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 position.

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

Pump leakage diagnosis

Power steering pump

NOTE: The power steering pump is mounted in the same position on LHD and RHD vehicles. On 4.0L RHD vehicles the front bracket is different. The service procedures are the same.

REMOVAL

(1) Remove serpentine drive belt, refer to Group 7 Cooling.

(2) Remove pressure and return hoses from pump, and drain pump.

(3) Remove 3 pump mounting bolts through pulley access holes.

(4) Loosen the 3 pump bracket bolts (Fig. 3) and (Fig. 4).

(5) Tilt pump downward and remove from engine.

(6) Remove pulley from pump.

INSTALLATION

(1) Install pulley on pump.

(2) Install pump on engine.

(3) Tighten pump bracket bolts to 47 N·m (35 ft.

lbs.).

(4) Install 3 pump mounting bolts and tighten to 27 N·m (20 ft. lbs.).

(5) Install the pressure and return hoses to pump.

(6) Install drive belt, refer to Group 7 Cooling.

(7) Add power steering fluid and perform Power Steering Pump Initial Operation.

Pump reservoir-2.5L

REMOVAL

(1) Remove the hoses from the bottom of the reservoir and drain the reservoir.

(2) Remove the push-in fastener from the top of the fan shroud.

(3) Slide reservoir up off the fan shroud.

INSTALLATION

(1) Slide reservoir down onto fan shroud.

(2) Install the push-in fastener in the top of fan shroud.

Fig. 3 Pump Mounting LHD

1 - PUMP BRACKET
2 - PUMP ASSEMBLY 2.5L
3 - PUMP ASSEMBLY 4.0L

(3) Install the pump hoses.

(4) Fill reservoir to proper level. Refer to Power Steering Pump Initial Operation.

Pump pulley

DISASSEMBLY

(1) Remove pump assembly.

(2) Remove pulley from pump with Puller C-4333 or equivalent puller (Fig. 5).

ASSEMBLY

NOTE: The pulley is marked front for installation.

(1) Replace pulley if bent, cracked, or loose.

(2) Install pulley on pump with Installer C-4063-B or equivalent installer (Fig. 6). The pulley must be flush with the end of the shaft. Ensure the tool and pulley are aligned with the pump shaft.

(3) Install pump assembly.

(4) With Serpentine Belt, run engine until warm (5 min.) and note any belt chirp. If chirp exists, move pulley outward approximately 0.5 mm (0.020 in.). If noise increases, press on 1.0 mm (0.040 in.). Be careful that pulley does not contact mounting bolts.

Pump reservoir

DISASSEMBLY

(1) Remove power steering pump.

(2) Clean exterior of pump.

(3) Clamp the pump body in a soft jaw vice.

(4) Pry up tab and slide the retaining clips off (Fig.

7).

NOTE: Use new retaining clips for installation.

(5) Remove fluid reservoir from pump body.

Remove and discard O-ring seal.

ASSEMBLY

(1) Lubricate new O-ring Seal with Mopar Power Steering Fluid or equivalent.

Fig. 4 Pump Mounting 4.0L RHD

1 - BRACKET
2 - PUMP ASSEMBLY

Fig. 5 Pulley Removal

1 - POWER STEERING PUMP DRIVE PULLEY
2 - SPECIAL TOOL C-4333

(2) Install O-ring seal in housing.

(3) Install reservoir onto housing.

(4) Slide and tap in new reservoir retainer clips until tab locks to housing.

Fig. 6 Pulley Installation

1 - POWER STEERING PUMP DRIVE PULLEY
2 - SPECIAL TOOL C-4063-B

(5) Install power steering pump.

(6) Add power steering fluid, refer to Pump Initial Operation.

Fig. 7 Pump Reservoir Clips

1 - RESERVOIR
2 - RETAINING CLIPS