Home » OM 617 » OM 617 – Disassembly, cleaning, assembly and adjustment of injection nozzles

OM 617 – Disassembly, cleaning, assembly and adjustment of injection nozzles

Note
The injection nozzle with Bosch designation DN 0 SD 240 i s a perforated pintle nozzle. It differs from
pintle nozzle by a crosswise bore and a longitudinal bore (1 4 and 15) in throttle pintle. I n addition, a
maintenance-free rod-type filter (1 3) i s pressed into injection nozzle holder top (7).

The advantage of a perforated pintle nozzle is better injection at lower volume and less load, as well as a reduction of coking on ring gap.

Disassembly
1. Clamp injection nozzle holder top (7) with protective jaws into vise in such a manner that the
leak oil line connections are not damaged.
2. Loosen injection nozzle holder bottom (5) with socket wrench insert and screw off.

5. lnjection nozzle holder bottom
7. Injection nozzle holder top

3. Remove steel washer ( 10 ) , compression spring (6), pressure pin (4),nozzle holder element (3)and
nozzle body (2) with nozzle needle (1).

Attention!
During disassembly make sure that the nozzle body, the nozzle needle and the individual components are not mixed up among each other.

Cleaning
4. Brush off combustion deposits outside on face of nozzle body ( 2 ) , mainly around nozzle mouth, by
means of a brass brush.
Touch up nozzle holder element (3) and nozzle body (2) on face of both sides on a surface plate.

5. Clean pressure chamber (5) of nozzle body by means of ring groove scraper.

6. Clean nozzle needle seat in nozzle body with cleaning cutter from inside out. Do not clean from
outside (to guide cleaning cutter or to prevent canting). Do not exert excessive pressure with cleaning cutter.

7. Clean longitudinal and cross bore of nozzle needle with cleaning needle 0.13 mm dia.

8. Clean nozzle needle with brass brush.

Testing nozzle needle
9. Visual test. Upon cleaning, test used nozzles visually. Test nozzle needle for dented or rough needle seat and for worn or damaged spray pintle. Replace damaged nozzles.

10. Slide test. For this purpose, immerse nozzle needle and nozzle body in filtered diesel fuel and
insert nozzle needle into nozzle body. With nozzle needle held vertically the nozzle needle, which is
pulled out by approx. one third, should slide back on i t s seat under its own weight. Replace injection
nozzle, if required.

Assembly
11. Insert all parts in vice versa sequence into injection nozzle holder bottom (5) and screw on injection
nozzle holder top (71, while inserting pressure pin (4) with bore into nozzle needle (1).

12. Clamp injection nozzle holder top (7) with protective jaws into vise and tighten injection nozzle
holder bottom (5) to 70-80 Nm.

Testing
13. Test injection nozzles for jet, buzzing noise, opening (ejection) pressure and for leaks (07.1-1 35).

Adjusting
14. Install or remove steel washers (10) between compression spring (6) and injection nozzle holder
top (7) to maintain specified ejection (opening) pressure, if required for adjustment.

Putting in = increased ejection pressure
Taking out = decreased ejection pressure

Washers are available 1.0 to 1.8 mm thick in steps of 0.05 mm. An increase of preload by 0.05 mm increases ejection pressure by approx. 3.0 bar gauge pressure.

 

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