Bayer HealthCare RapidPoint 400 Series Service Manual page 348

When reinstalling the cartridge interface assembly, do not bump the
NOTE:
spring plate and locking tabs on the pump housing or the spring plate can
pop off and interfere with system operation.
7. Reassemble in the reverse order. Refer to Replacing the Cartridge
Interface Assembly on page 309 and Installing the Rear Cover,
Cartridge Interface Assembly, and Power Module Assembly on
page 378.
348 Rev. C