Hydraulic Pressure Testing With H-31 System
CHECKING OPERATION OF POWER STEERINGH 31 System
- Engine at Operating Temperature -
Check hydraulic fluid level in tank. Check all hose connections and equipment (pump, brake booster. sower flow regulator and steering gear) for leaks before checking operation.
Discharging Pressure:
Stop engine and operate brake pedal about 20 times.
Disconnect line on power flow regulator. Mount Special Tool 32 4 007 on power flow regulator and install Special Tools 32 4 000 and 32 4 008 between the pump and power flow regulator,
1. Pump connection
2. Power flow regulator or steering gear connection
A = Shut-off valve (low pressure: 0 to 15 bar /0 to 213 psi):
Caution!
Shutoff valve (A) must always be closed for high pressure tests to avoid damaging the pressure tester.
B = Shutoff valve (high pressure: 0 to 150 bar /0 to 2133 psi)
Open valve (B).
Close valve (A).
Start engine and fill tank with hydr. fluid.
Bleeding System:
Turn steering wheel twice each against left and right locks.
Operate brake pedal 5 times, wait 30 seconds and operate pedal another 5 times. Hydraulic fluid temperature should be approx. 50° (122° F) for all tests.
Turning the steering wheel against locks with the engine running could cause a rise in the temperature.
1. Checking Flow Pressure:
Open valve (B).
Close valve (A) and run engine.
Open valve (A) and reed pressure when pressure is less than 15 bar (213 psi).
Max. permissible flow pressure of 8 bar (114 Psi) must not be exceeded.
Pressure Greater than 8 bar (114 psi):
Continue with 32 41 505.
2. Checking Pump:
Install pressure taster between pump and power flow regulator.
Close valve (A). Start engine.
Close valve (B) max. 10 seconds and read pressure.
Rated pump pressure ± 10 % should be reached.
Rated pressure exceeded replace pump
Rated pressure not reached, check drive belt tightness.
Repeat pressure still not reached, replace pump.
3. Checking Reservoir Charging Pressure:
Pressure tester between pump and power flow regulator.
System bled.
Engine not started.
Valve (B) open.
Valve (A) closed.
Start engine and observe pressure tester. Pressure must rise to max. 57 bar (811 psi) and then drop immediately to less than 8 bar (114 psi).
If max. permissible pressure of 57 bar (811 psi) is exceeded or there is no immediate pressure drop after reaching the maximum permissible pressure, replace power flow regulator.
4. Power Steering:
Pressure tester between pump and power flow regulator.
System bled.
Valve (B) open.
Valve (A) closed.
Engine not started.
Lift car.
Stop steering from reaching final left lock by 1/2 to 3/4 steering wheel turn with a piece of wood or something similar,
Start engine.
Pull steering wheel against final left lock with a force of force of 100 N (22 lbs.) (force meter) about 5 seconds and read pressure.
Limit final right lock and repeat test on right lock.
If pressure values are lower than pump pressure determined in point 2, replace steering gear.
5. Checking Mechanical Play of Steering.
- Pressure point adjusted.
- No play in steering column.
Pressure taster between pump and power flow regulator.
System bled.
Valve (B) open.
Valve (A) Closed.
Engine not started.
Steering drop arm held in straight ahead position with Special Tool 32 4 060.
Paste strips of paper on the steering wheel hub and casing upper Section.
Make mark (center) on steering wheel hub.
Start engine:
Open valve (A).
Read flow pressure.
Turn steering wheel counterclockwise until pressure tester shows 1 bar (14 psi) more pressure than the flow pressure value. Mark position of steering wheel hub Repeat this in clockwise direction If max. permissible travel (C) = 7 mm (0.276") is exceeded, replace the Steering gear.
Remove special tool holder and pressure tester. Bleed hydraulic system and, if necessary. add hydraulic fluid.