Page 291 - CTS - Mechanic Diesel - TP

MECHANIC DIESEL - CITS

EXERCISE 15.7: Servicing Unit Injector

Objectives

At the end of this exercise you shall be able to
• to dismantle the unit injector
• to clean and injection parts
• to Reassemble the unit injection
• to test the spray pattern & opening pressure.
Requirements

Tools/Equipments Materials
• Trainee’s tool kit - 1 No. • Tray - as reqd.
Machines • Cottoncloth - as reqd.
• Kerosene - as reqd.
• Unit Injector - 1 No. • Diesel - as reqd.
• Injector holding fixture - 1 No.
• Injector test bench - 1 No.
• Air compressor - 1 No.

Procedure

Dismantling
1 Mount it in a holding fixture and remove the filter caps from the inlet side.
2 Remove the filterfrom inlet side andcheck up the filter seating

3 To remove the stop pin, push the follower slightly down without hand and with plier in the other hand.
4 Turn the stop pin 90° and with draw it.
5 On the fuel pinchar unit injector, push the follower down.
6 Rotate clock wise to align the relief lot with roll pin and with draw the follower.

7 Turn the injector fixing vise about 145° to 15° to with draw the follower, & follower spring and plunger,
8 Again to tilt the injector vise about 180 and using a deep socket spanner to loose the injector nut and take it
out.

9 Keep the spray tip separately with needle valve.
Note: Keep spring cage, spring seat, spring check valve cage and check valve in the separate
container with oil.
10 Remove the bush and insert the plunger
11 Remove the gear container and remove the control rock.
Cleaning & inspection: Clean all individual parts separately using solvent fuel etc.

Inspection
Inspect the body, threads of the fuel filter cap and the nut. Check the dowel pin. Resurface the ring face with a
reamer by using a straight flute reamer any nicks and burrs from the bore turn the reamer only in a clock wise
direction to prevent damage the flutes. Check to contact surface of the bush, other part must be check up&
inspect

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