5
Maintenance
Replacing the Primary Piston Seals
98
Accela 600 and 1250 Pump Hardware Manual
Thermo Scientific
4. Insert the piston into the primary seal no more than 3 mm (0.12 in.) (see
). The
primary seal is inside the displacement chamber.
Figure 97.
Displacement chamber with piston inserted
5. Because the piston is fragile, gently remove the seal by pulling on the piston while
applying side force. Do not allow the piston to touch any metal parts.
6. Remove the primary piston seal from the piston and discard the primary piston seal.
7. Check the piston for contamination and scratches, and then do the following:
• If the piston is in good condition, go to the next step.
• If the piston is scratched, replace it.
• If the piston needs cleaning, clean it as described in
8. Insert the piston into the guide bushing.
9. With the spring (see
) facing away from the guide bushing, slide the
replacement seal over the piston. Ensure that the replacement seal is flush with the guide
bushing and the piston protrudes out of the seal by 6 mm (0.24 in.) (see
).
Figure 98.
Piston, guide bushing, and replacement piston seal assembly
Piston
Displacement chamber
Guide bushing
6 mm (0.24 in.)
Piston seal
