Measuring hydraulic throw-out bearings (usually referred to as bearings in hydraulic clutches) requires a combination of the specific type and size of the bearing, the operating environment and the parameters to be measured. The following are some common measurement methods and steps for bearing measurement in general hydraulic systems:

I. Measurement of hydraulic throw bearing preparation

1. Tool preparation: According to the size and type of bearing, prepare suitable measuring tools, such as outside micrometer, inside diameter ruler, wall thickness micrometer, lever micrometer and so on. Ensure that the accuracy of the measuring tools meets the measurement requirements.

2. Environment preparation: Make sure the measuring environment is clean, no vibration, no magnetic field interference to ensure the accuracy of the measurement results.

Second, the measurement of hydraulic throwing bearing method

1. Preparation:

Firstly, make sure the vehicle is in a safe lifting position and the clutch assembly is accessible. Ensure that the clutch slave cylinder is fully compressed.

   - Ensure that the clutch system has been completely disassembled and the throwout bearing can be removed from the clutch assembly.

   - Prepare measuring tools such as calipers, micrometers, depth gauges, etc.

2. Measure external dimensions:

   - Use calipers or micrometers to measure the outside diameter, inside diameter and width of the bearing.

   - Record these dimensions as reference.

3. Internal clearance measurement:

   - To check the internal clearance of the bearing, you can use a plastic clearance gauge or the probe of a micrometer.

   - Measure the clearance between the bearing inner ring and the rollers to ensure that the clearance is within the manufacturer's recommended range.

4. Axial clearance measurement:

   - Use a depth gauge or a special measuring tool to measure the axial clearance of the bearing, i.e. the distance the bearing moves back and forth when it is in the mounting position.

5. Setting Air Clearance: 

For most applications, the ideal air clearance (i.e., the distance between the bearing and the platen) is approximately 1/8 inch to 1/4 inch, or approximately 4 mm to 6.4 mm. The exact value may vary depending on the manufacturer's recommendation, which is usually about 4 mm (or about 3/16 inch).

6. ADJUSTMENT: 

If adjustment is required, this is usually done by adjusting the position of the clutch cable or slave cylinder to ensure that the correct air gap is achieved.

7. Check seals and dust caps:

   - Check that the bearing seals and dust caps are in good condition and if they are damaged, they will need to be replaced as well.

8. Record data:

   - Record all measured data for comparison with new bearing specifications or for subsequent troubleshooting.

9. Caution:

   - When measuring, make sure the bearing is clean and free of oil, so as not to affect the measuring accuracy.

   - Hold the bearing gently during measurement to avoid additional damage to the bearing.

If any of the bearing dimensions are outside of the specified tolerances, or if there is visible wear or damage, then the bearing may need to be replaced. As the measurement and installation of hydraulic throwout bearings requires a certain level of expertise and skill, it is recommended that these operations be performed by a professional automotive service technician if inexperienced.