7 семестр (Бормотов А) / 1man_bw_l23_30_chn_23_30_instruktsiya_po_ekspluatatsii_1 / MAN-BW L23-30 H Vol-1 (Instruction)+

Dismounting of fuel injection pump

1. Dismount the fuel injection pipe pos. 1 fig 1 and the fuel inlet pipe pos 2.

2. Separate the spring loaded lever from the regulating rod on the fuel injection pump.

1 2

Fig 1 View from Control Side

3.Remove the pipe for lub.oil and drain.

4.Remove the screws in the bottom flange (4 pieces) and take the fuel injection pump away.

Separation of fuel injection pump.

5.If necessary, clean the exterior of the injection pump.

6.Mount the injection pump in the clamping bracket PYO-W020 (see plate 52014 item 037), on the test pump.

7. Press the thrust cap (N) fig. 2 downwards and remove the securing ring (P). Remove the thrust cap

(N) with lower spring plate (O) and plunger (M). Be sure not to damage the plunger.

D

A

1. Back-up ring (spirally coiled)

2. O-ring inside dia. 45.7 mm x 2.6 3. O-ring inside dia. 51 mm x 3

4. Back-up ring

5. O-ring inside dia. 43 mm x 3.5 6. O-ring inside dia. 37 mm x 3

8.Take out the plunger spring (L), upper spring plate (K) and pinion (J). If necessary remove the lock ring (R) and guide pin (I) and dismount the regulating rod (H) as well as the cap screw in the opposite end of the regulating rod (H).

9.Unscrew the four screws (A) and remove the connecting piece (B). Take out the valve spring (D) and the non-return valve (F).

10.Loosen and remove the four screws (C) and take out the barrel (E).

11.Remove all the O-rings and back-up rings from the injection pump.

12.All parts must be cleaned, using kerosene or gas oil and a hand brush (not a steel brush).

Blow through the holes for sealing oil in the pump houses and the barrel (E).

Inspection of fuel injection pump:

13. Insert plunger (M) and non-return valve (F) into the barrel (E) after wetting with clean gas oil. Plunger and non-return valve must slide into the barrel by their own weight.

Plunger (M)

Fig 3 Clearance between Lower Spring Plate and Plunger

14.The axial clearance between lower spring plate and plunger foot must not exceed 0.25 mm. The clearance between lower spring plate and plunger foot is 0.05 to 0.1 mm when new. See fig 3.

15.Check the cavitation plugs (G) for wear and renew if necessary.

16.Barrel (E), plunger (M) and non-return valve

(F)are manufactured to very close tolerances. Any attempt to refinish these parts causes alterat-

ions of the tolerances and must therefore NOT be carried out.

If during the visual inspection of the parts, heavy abrasion symptoms or damage can be observed, the part in question must be replaced.

Assembling of fuel injection pump:

17. When assembling the injection pump, proceed in the reverse order to disassembling. Pay attention to the following:

Marking on regulating rod

Tooth with chamfer

Marking on pinion

Fig 4 Mounting of Regulating Rod Mechanism

A.At initial tightening up of new parts the following

(C)for barrel (E).

Tighten screws to 90 Nm, loosen and tighten again to 90 Nm and then tighten to 90 Nm + 10 Nm. Employ the same procedure when tightening the other pump components for the first time.

Stopped engine

Shut-off starting air

Shut-off cooling water

Shut-off fuel oil

Shut-off cooling oil

Stopped lub. oil circul.

Description:

Dismounting, overhaul, pressure testing and mounting of fuel injection valve.

Starting position:

Top cover on the cylinder head and front cover on the fuel injection pump has been dismounted.

Related procedure:

Antiseizure product.

(Copaslip, Molykote GN Plus or similar).

Replacement and wearing parts:

L23/30H

The fuel injection valve is the single component that has the greatest influence on the diesel engine condition. Various forms of operation and quality of fuel oil affect the overhaul intervals. In some cases it may be necessary to shorten the prescribed intervals.

Dismounting and cleaning:

1. Dismount the fuel injection valve from the cylinder head by means of the special tool as shown in fig. 1.

Fig 1 Dismounting of fuel injection valve from cylinder head.

2. Mount the fuel injection valve into the clamping bracket VTO-W020 (see plate 52014, item 025) on the pressure testing pump, and loosen the lock nut

(B) fig 2.

Unstress the nozzle spring by turning the adjusting screw (D).

3. Clean the lower part of the nozzle (J) from carbonized oil deposits before dismantling the nozzle nut (H). Remove the nozzle nut (H) and the nozzle

(J).

Fig 2 Fuel injection valve.

Attention!

Do not damage the lapped surface.

4.The nozzle spring (F) and the spring spindle (G), are to be taken out by loosening the adjusting screw (D), completely.

5.All parts must be cleaned with kerosene or gas oil and a hard brush (not a steel brush).

6.Clean the nozzle holes of charred coke by means of the supplied special drill (see plate 5201401H item 108) with holder.

7.Clean the cooling chamber and the cooling ducts in the nozzle guide and injector body by placing these in a cleaning liquid and then blow through the parts with dry working air.

Inspection of the parts:

8.Nozzles are matched by lapping and are therefore only interchangeable as units. Insert nozzle needle with gas oil in the needle guide. It must be controlled whether the nozzle needle slides down by its dead weight on its seat.

9.If the holes are oval worn, which is checked with of a magnifying glass, the nozzle must be scrapped.

10.The best way, however, to check if the holes are worn out is to control the flow rate of the nozzle which, in general, only can be made at the manufacturer's works on a special test stand.

11.Every effort to refinish will result in alterations of these values and malfunction of the nozzle. If heavy abrasion symptoms, respectively damages are observed at the visual inspection of the parts, the parts in question must be replaced.

Reassembling:

12.When all parts have been overhauled, found in good order and carefully cleaned, assemble the fuel injection valve again.

13.When assembling the injection valve, proceed in the opposite order compared to the disassembly. Pay attention to the following:

A.Lubricate the threads on the adjusting screw

(D)with lub. oil, and the threads of the nozzle holder for the nozzle nut. The shoulder of the nozzle which is in contact with the nozzle nut, must be lubricated with an antiseizure product.

B.The sealing plane surface of body and nozzle must be wiped dry with paper.

C.Renew the sealing rings (C) and (E).

D.Tightentorquefornozzlenut (seepage500.40.)

L23/30H

Pressure testing of fuel injection valve:

14.The most effective checking of the fuel valves is obtained through pressure testing, preferably carried out after each overhaul and also in case of irregularities in operation. The pressure testing is carried out in the following way by means of the pressure testing apparatus supplied.

15.Mount the fuel injection valve in the bracket VTO-W020 (see plate 52014 item no. 25) again. The bracket to be in such a position that the nozzle of the injector is pointing downwards.

16.For test of the injection pressure and atomizing mount the test pipe VTO-W021 (see plate 52014 item 049), increase pressure by means of the lever on the test pump, and adjust the opening pressure to

320bar, by the adjusting screw (D), see fig 2, then tighten lock nut (B) and check opening pressure again.

Do not expect chattering, but make sure that the nozzle spray from all holes in the same angle. The nozzle might chatter if the lever is worked very fast, actually by hitting it.

Do not expect a nozzle tip with more than 1000 running hours to perform like a new nozzle in the test pump.

Then increase the pressure to 300 bar and keep the pressure by working the lever slowly downwards. When the pressure is kept at 300 bar, there should be no more than one drip from the nozzle tip for approx. 3-5 sec.

WARNING: Keep out of the fuel jets as they will penetrate the skin. Fuel which has penetrated the skin can cause painful inflammations (blood poisoning).