Series 50 – Section 3.3 Oil Pressure Regulator Valve

Section 3.3
Oil Pressure Regulator Valve

An oil pressure regulator valve maintains stable lubricating oil pressure within the engine, regardless of the oil temperature. Oil leaving the pump under pressure passes into the pressure relief valve. The valve is installed into a vertically drilled passage in the balance assembly. See Figure "Oil Pressure Regulator and Relief Valve Mounting" .‪

Figure 1. Oil Pressure Regulator and Relief Valve Mounting

The oil pressure regulator consists of a valve body, a hollow, piston-type valve, a spring, a spring seat and a pin to retain the valve assembly within the valve body. See Figure "Oil Pressure Regulator and Relief Valve Details" .‪

1. Pin‪	5. Valve‪
2. Pressure Regulator Pin Location‪	6. Spring‪
3. Pressure Relief Valve Pin Location‪	7. Spring Seat‪
4. Valve Body‪	‪

Figure 2. Oil Pressure Regulator and Relief Valve Details

The valve is held on its seat by the spring, which is compressed by the pin in back of the spring seat. The entire assembly is bolted to the balance support and sealed against leaks by a gasket between the block and valve body. When conditions are such that the oil pressure at the regulator valve exceeds 427 kPa (62 lb/in.² ), the valve begins to be forced from its seat and oil from the engine gallery is bypassed to the engine oil pan. Thus, stable lubricating oil pressure is maintained at all times.‪

Note: Whenever the lubricating oil pump is removed for inspection, remove the regulator valve and spring and thoroughly clean and inspect them.

Section 3.3.1
Repair or Replacement of Oil Pressure Regulator Valve

To determine if repair is possible or replacement is necessary, perform the following procedure. See Figure "Flowchart for Repair or Replacement of Oil Pressure Regulator Valve" .‪

Figure 3. Flowchart for Repair or Replacement of Oil Pressure Regulator Valve

Section 3.3.2
Draining and Removal of Oil Pressure Regulator Valve

Precleaning is not necessary.‪

Remove the oil pressure regulator valve as follows:‪

1. Drain the lubricating oil and remove the oil pan. Refer to "3.9.2 Cleaning and Removal of Oil Pan" .
2. Remove the two regulator-to-balance support attaching bolts and washers.
3. Tap the regulator body lightly to loosen it from the balance support.
4. Remove the oil pressure regulator valve.

Section 3.3.3
Disassembly of Oil Pressure Regulator Valve

Disassemble the oil pressure regulator valve as follows:‪

1. Clamp the regulator in the soft jaws of a bench vise.

   EYE INJURY ‪
   To avoid injury from flying parts when working with components under spring tension, wear adequate eye protection (face shield or safety goggles).‪

2. Depress spring seat and hold it securely while removing the spring seat retaining pin from the regulator body.
3. Remove the spring seat, spring and valve from the regulator body.

Section 3.3.3.1
Inspection of Oil Pressure Regulator Valve

Inspect the oil pressure regulator valve as follows:‪

1. Clean all of the oil pressure regulator valve components in fuel oil.

   EYE INJURY ‪
   To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 276 kPa (40 psi) air pressure.‪

2. Dry the components with compressed air.
3. Inspect the oil pressure regulator valve for movement.
   1. Check to see if the oil pressure regulator valve moves freely in the valve body.
   2. If oil pressure regulator valve binds, replace it with a new part.
4. Inspect the components for wear or damage.
   1. Check to see if valve or the valve body are scored.
   2. If the valve or valve body parts cannot be cleaned up with a fine emery cloth, replace with new parts.
5. Inspect spring for following:
   1. Check for pitting or fractures.
   2. If spring is damaged, replace it with a new part.

Section 3.3.4
Assembly of Oil Pressure Regulator Valve

Assemble the regulator valve as follows: ‪

1. Apply clean engine oil to the outer face of the valve.
2. Slide it into the regulator body, closed end first. See Figure "Oil Pressure Regulator and Relief Valve Details" .
   

   1. Pin‪	5. Valve‪
   2. Pressure Regulator Pin Location‪	6. Spring‪
   3. Pressure Relief Valve Pin Location‪	7. Spring Seat‪
   4. Valve Body‪	‪

   Figure 4. Oil Pressure Regulator and Relief Valve Details

3. Insert the spring in the valve and install the spring seat.
4. While compressing the spring, install the retaining pin behind the spring seat.
5. Press the pin flush to 0.254 mm (0.010 in.) below the surface of the valve body.

   Note: The valve body has two retaining pin holes. Install the pin in the outermost hole for the regulator valve. The retaining pin must be positioned correctly so the proper valve opening pressure will be obtained. Although the same casting is used for both the pressure regulator and relief valves, the regulator valve has a slightly larger opening machined into the side. See Figure "Comparison of Pressure Regulator and Relief Valve Assemblies" .

   

   Figure 5. Comparison of Pressure Regulator and Relief Valve Assemblies

Section 3.3.5
Installation of Oil Pressure Regulator Valve

Install the oil pressure regulator valve as follows:‪

1. Remove all traces of old gasket material from the mating surfaces of the regulator body and the balance support.

   Note: Detroit Diesel has determined that, when the oil pressure regulator is properly fastened to the cylinder block, a gasket between the block oil gallery and the valve body is not required. Due to the flatness tolerances of the valve face and the block mounting surfaces, the seepage of lubricating oil around the valve body at this joint is minimal and has no significant effect on oil system pressure requirements. For this reason, the regulator valve-to-block gasket has been eliminated from all Series 50 engines.

2. Secure the regulator assembly to the balance support with two bolts. Torque the bolts to 30-38 N·m (22-28 lb·ft).
3. Refer to "11.1.2 Lubrication System" for verification of proper oil pressure regulator installation.