DISASSEMBLY, OVERHAUL, AND TESTING OF BOSCH CRIN 4.2 INJECTORS WITH REDAT SPARE PARTS AND EQUIPMENT

REDAT S.p.A. is a manufacturing company specialized in the production of spare parts and equipment for the maintenance and repair of injectors for numerous Diesel engine brands and models used worldwide, with specific expertise in the heavy-duty sector.

Proper maintenance of a Diesel injector requires precise procedures, dedicated equipment, and components capable of ensuring reliable performance over time.

In the video filmed with our technicians directly in our workshop, we illustrate the complete overhaul process of a Bosch CRIN 4.2 injector, from disassembly through to final testing on a Hartridge test bench at our Villastellone facility in Italy.

This video shows injector repair procedures carried out by REDAT S.p.A. technicians.

The special tools and procedures shown in this video have been developed through years of experience. They are not intended to replace the official repair procedures issued by injector manufacturers but may be used as an introduction to injector repair.

1.     Bosch CRIN 4.2 injector disassembly

The disassembly procedure begins by removing the O-rings using hook tool 4 021 678. The injector is then positioned on fixing block 4 021 902 and secured in a vice to ensure stable and safe working conditions.

Using wrench 4 021 905, the nozzle nut is removed. Pliers 4 020 700 are then used to extract cage 1 214 512 and gain access to the components housed inside the bushing.

Open-end wrench 4 021 183 is used to remove the injector nut, while wrench 4 021 912 is used to unscrew the solenoid nut and separate the solenoid assembly from the injector body. Further disassembly of the solenoid is not recommended, as this could damage the electrical wires inside it.

Once disassembly has been completed, all components must be thoroughly cleaned and inspected. Damaged or high-wear parts, such as springs, O-rings, filter, valve, plunger assembly, and nozzle, can then be replaced with spare parts such as those manufactured by REDAT S.p.A. for original injector models..

2.     Bosch CRIN 4.2 injector assembly, adjustment, and calibration

Assembly is carried out by following the reverse order of the previously described operations while observing the specified tightening torques. The solenoid assembly is reinstalled, and its retaining nut is tightened to 90 Nm using wrench 4 021 912.

The injector nut is also tightened to 90 Nm using wrench 4 021 183. The components are then assembled inside the bushing and adjusted using shim kits 1 214 921 and 1 214 922.

Cage 1 214 512 is secured inside the bushing using pliers 4 020 700. The nozzle is calibrated using compensation washer kit 1 214 535. Finally, the nozzle nut is tightened to 105 Nm using wrench 4 021 905.

After installing the O-rings and the flame washer, the injector is fully assembled and ready for the subsequent inspection procedures.

3.     Injector filter replacement

The video also demonstrates the procedure for removing and replacing the injector filter. Threaded bushing 4 021 901 is screwed onto the injector body delivery fitting together with male guide bushing 4 021 549.

Tap 4 021 552, mounted on tap wrench 4 021 553, is used to cut a thread into the filter. During this operation, it is advisable to use a suitable lubricant to prevent seizure.

Extractor nut 4 021 551 and threaded pin 4 021 603 are then used to progressively extract the filter from its seat..

The new filter 1 216 111 is installed using pin 4 022 170, pushing it fully home inside the guide bushing. If necessary, the operation can be completed by carefully using a hammer.

4.     Final testing on the Hartridge test bench

At the end of the overhaul process, the Bosch CRIN 4.2 injector is installed on the Hartridge test bench in the REDAT workshop using the dedicated equipment. The injector brand and model are selected in the software, which automatically starts the complete testing sequence.

The results are displayed directly on the monitor: a green indicator confirms that the test has been passed, while a red indicator highlights a non-compliant result. Each individual test can be selected to display the recorded data in detail.

All components manufactured by REDAT are tested in our workshop to ensure quality and performance equivalent to original spare parts. Through the online catalogues available on the REDAT website, it is possible to identify compatible spare part and equipment reference numbers, consult product specifications, and check stock availability.

Bosch Iniettori - Guarnizioni - Spessori

Contact our team for more information at +39 011 979 1111 or email us at sales@redat.com