Ransburg Evolver Solvent Applicator 79190-XXXXXXXX - Manual (Page 37)

32
Evolver Solventborne Robotic Atomizers - Maintenance
Rear Needle Replacement
(See Figure 8)
1. Remove the air cap, fluid tip, and the fluid nozzle
as described in steps 1 through 8 of the "Fluid Tip,
Nozzle, and Front Needle Replacement" in the "Main-
tenance" section.
2. Remove the rear needle [6] and lock nuts [4]
and [5] as an assembly. Pull the assembly out from
the rear of the spray head.
> Fluid seal [29], seal washer [28], and seal spring
[27], will come free at this point. Place hand over
end as not to drop parts.
C A U T I O N
!
3. Inspect metal portion of the rear needle [6] for
excessive wear. If wear is observed (longitudinal
grooves or a noticeable reduction in diameter), re-
place the needle. Remove the two (2) lock nuts from
the rear needle and save. When ever replacing rear
needle section, you must also replace
the seal [29] at the same time.
4. Place the rear needle assembly back into the
spray head.
5. Place seal spring [27] over the rear needle in
the front end of the spray head. Hold the spray
head upward as the spring will want to fall out.
6. Still holding the spray head upward, place the
seal washer [28] and thread the fluid seal [29] onto
the rear needle. The tapered end of the fluid seal
should be pointed toward the front of the gun.
7. Insert the lubricated o-ring [30] into the gun head.
Gently push, with small flat object, down upon its
seating edge. Be careful not to push
o-rings into fluid groove (see Figure 8).
8. Reassemble fluid nozzle [32] by pushing the
nozzle into the spray head and through the o-ring
until the threads engage. Screw the nozzle into
the spray head. Torque to 23-25 lbs•in (2.6-2.8 Nm).
Plastic threads damage easily; do not overtighten.
Note the front flange of the fluid nozzle will not seat
flush against the spray head.
9. Apply Loctite #222 Low Strength (purple) Thread-
locker into the threads of plastic front
needle [31] before assembling onto the rear needle.
Be sure that the rear needle assembly is pushed all
the way forward before threading on front needle.
10. Reassemble fluid tip [34]. Hand tighten first;
then with a small wrench turn an additional 30 °.
11. Reinstall the two (2) lock nuts [4] and [5] in the
correct order on the back needle as shown making
sure to maintain an 1/16" clearance (see Figure 8).
12. Reassemble air cap [35] and air cap retainer
[33]. The air cap rotate positioning pins must be
engaged with the air cap locator holes before final
tightning.
13. Apply a thin film of petroleum jelly to valve
spring [3] and needle spring [2], and insert back into
the end cap. Screw end cap [1] back on.
14. Lubricate all of the o-rings on the underside of
the spray head with petroleum jelly, and apply a thin
coat of dielectric grease to the grooves of the spray
head and the valve manifold before reassembly.
15. Reattach spray head to manifold block by engag-
ing the connection plug [24] into the mounting block
cavity [3], and turn clockwise until head contacts stop
pin on the block.
Air Valve Removal
(See Figure 9)
1. After removal of end cap and spring, the air valve
can be pulled straight out the back of the head
assembly.
2. Inspect and replace the u-cup [8], if necessary, by
holding the air valve shaft on it's flats and loosening
the piston nut [7] counter-clockwise.
3. Remove the seal carrier with seal removal tool
[B].
4. Use a bent hook to reach inside the air valve
bushing [14], grip slot and pull out. Use the same
procedure to pull out the rear seal carrier [17].
5. Remove and replace all o-rings if necessary.
6. O-rings [12] and [18] must be installed inside
their mating parts (see Figure 9).
AA-03-02.11