Pump Flow and Pressure Tests

The pump flow and pressure tests will confirm or rule out the power steering pump (3A674) as the cause of steering system problems.

Prior to performing the pump flow and pressure tests, perform Pinpoint Test A in this section.

If the system tests OK, or the concerns have been corrected, and the loss of assist still exists, test the power steering pump flow and pressure to determine whether the trouble is in the power steering pump, steering gear (3504) or power steering pump valve (3A561) using the following test equipment.

F-150, F-250, F-350, F-Super Duty Chassis Cab and Bronco

Test Equipment

• engine tachometer
• thermometer — -17°C to 140°C (0°F to 300°F)
• Power Steering Analyzer D79L-33610-A (Rotunda Model 014-00207) or equivalent
• one set of adapter fittings

Test Procedure

 CAUTION: Possible contamination of the power steering system fluid may cause permanent damage to gauges and instruments incorporated in the analyzer.

This procedure used in conjunction with Power Steering System Analyzer D79L-33610-A (Rotunda Model 014-00207) or equivalent provides a method for checking the complete power steering system. The analyzer can be used to determine the cause of hard steering and/or lack of assist problems. The analyzer provides readouts for the following:

• system back pressure
• pump flow
• steering gear internal leakage
• power steering pump valve and cylinder internal leakage

Interpretation of the above readouts will determine which of the following conditions or components are the cause of the problem:

• restriction in hoses or fittings
• control valve and cylinder
• sticking gear valve
• inefficient pump cam pack
• sticking relief valve
• binding in suspension

F-Super Duty Motorhome Chassis Vehicles

Test Equipment

 CAUTION: Possible contamination of the power steering system fluid may cause permanent damage to gauges and instruments incorporated in the analyzer.

Power Steering System Analyzer D81T-33610-A (Rotunda Model 014-00230) or equivalent is to be used when the power steering system is suspected of erratic steering operation or insufficient power assist, and neitherpower steering pump norsteering gear have sustained failure or internal damage that may contaminate the fluid in the steering system. The analyzer consists of a pressure gauge, flow meter, shutoff valve, thermometer, hose and adapter attachments.

Test Procedures

Refer to Pinpoint Test D for testing procedures.

Item	Part Number	Description
1	3A697	Power Steering Oil Reservoir
2	—	Thermometer
3	3504	Steering Gear
4	—	Shutoff Valve (Part of D81T-33610-A)
5	D81T-33610-A	Flow Meter (Analyzer)
6	3A674	Power Steering Pump
7	—	Gauge (Part of D81T-33610-A)