2. Using a set of flat feeler gauges and a metal ruler, measure the gap between the pump cover and the rotors. Nominal value: 0.04-0.085 mm (inner rotor); 0.04-0.09 mm (outer rotor). If the gap is greater than the nominal, replace the rotors as a whole.
3. Measure the gap between the rotor teeth tips. Nominal value: 0.025-0.069 mm. If the gap is greater than the nominal value, replace the rotors as a whole.
4. Measure the clearance between the outer rotor and the pump body. Nominal value: 0.060-0.090 mm. If the clearance is greater than the nominal value, replace the rotor assemblies or the pump body.
5. Check the ease of movement of the pressure reducing valve plunger and the length of the spring in the free state. Nominal value: 46.6 mm. The valve plunger should freely fall into the seat under its own weight.