Pressure Regulator Test
Pressure Regulator Test126 Series
This test should be performed whenever pressure regulator switching noise is heard at short intervals while driving. Pressure tester kit No. 126589022100 is required for performing this test.
1. Release oil system pressure as follows:
a. Remove retaining ring, then disconnect adjusting switch control cable and pull control disk up to stop toward the rear to move valve unit adjusting to ``M'' position.
b. If stud on cable control adjusting switch has been accidentally released, proceed to step c to readjust control cable.
c. Completely push in instrument panel switch and move control disk forward up to stop into ``N'' position. Tighten stud, then actuate cable several times and ensure control disk rests against stop with switch pushed in.
2. Disconnect pressure line from pressure regulator.
3. Connect pressure gauge with distributor, pressure test line and vent screw between pressure regulator and pressure line.
Fig. 3 Valve unit adjusting switch:
4. Move adjusting switch, Fig. 3, into ``N'' position.
5. Start engine and run at approximately 3500 RPM and note cut-out pressure of pressure regulator on pressure gauge. Cut-out pressure should be 178-199 bar (2581-2886 psi) for a new pressure regulator, but may be as low as 165 bar (2393 psi) for a used pressure regulator.
6. With engine running, load front of vehicle so that level regulator switches to ``F'' position and note cut-in pressure indicated by a sudden rise in previously fallen pressure. Cut-in pressure should be 149-162 bar (2161-2349 psi) for a new pressure regulator, but may be as low as 140 bar (2030 psi) for a used pressure regulator.
7. Ensure difference between cut-in and cut-out pressure does not exceed 29-36 bar (421-522 psi) for a new pressure regulator or 20 bar (290 psi) for a used pressure regulator.
8. Ensure time required for pressure to increase from cut-in to cut-out pressure at 3250-3500 RPM does not exceed 10 seconds.
9. If pressure cannot be built up in pressure regulator, check throttle screw filter for contamination and correct as necessary.
10. If pressure regulator readings are not within specifications, perform pressure oil pump test as previously described and check valve unit for leaks as described under ``Valve Unit Leak Check.''
11. Release oil system pressure as described in step 1, then disconnect pressure gauge.