PCX5200 User’s Manual Chapter 4
4-4
5. Remove the pump from the chassis by 1) loosening the captive screw and 2)
unplugging the electrical connector. Place the pump in a more accessible place to
continue.
6. Remove the pump head from the pump as follows (Figure 4-1): with a 5/32˝ hex
wrench, remove the two bolts while holding the pump head against the pump housing
(the pump head is under spring tension). Gently pull the pump head straight out from
the pump housing, in line with the axis of the piston. Do not tilt the pump head
sideways; the piston may break.
7. Inspect the piston. If the piston has scratches on the sapphire, or significant corrosion
on the stainless steel piston holder, it should be replaced. Clean any deposits on the
sapphire with soapy water, deionized water, and then methanol. If the sapphire
cannot be cleaned, the piston should be replaced. Set the cleaned piston in a safe
place.
8. Remove the retainer assembly from the pump head. Insert the hooked end of the
installation tool into the pump head through the back-up washer and piston seal.
Discard the seal. The back-up washer is usually reusable. Do not scratch the walls of
the seal cavity with the tool.
9. Inspect the retainer. Clean the retainer if necessary. If there is evidence of wear, or
the piston does not fit snugly in the retainer, or the retainer grips the piston too
tightly, the retainer should be replaced.
10. This step is only necessary if there are signs of corrosion on the stainless steel piston
holder in step 7. Remove the pushrod from the pump housing with round-end
tweezers. Inspect for corrosion damage; clean or replace the pushrod if necessary.
Coat the pushrod with a light film of SAE 30 oil and re-install with the tweezers.
11. Inspect the pump head, paying special attention to the cavity for the piston seal.
Any scratches or irregularities will require replacement of the pump head. The
whole pump head may be cleaned with soapy water, and then with deionized water
in a sonicator bath.
Figure 4-1. Pump assembly with wash system. 1) Back-up Washer; 2) Piston Seal; 3) Wash
Cylinder; 4) Inlet Port of the Wash System; 5) Outlet Port of the Wash System; 6) O-ring
Piston
Outlet
Check-valve
Inlet
Check-valve
Pump
Head
Retainer Assy
Spring
Pushrod
Bushing
Compression Ring
1
2
3
16
2
4
5
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