Bio-Rad BioLogic Signal Import Module (SIM) - Manual (Page 211)

Problem Possible Cause Solution
Pump is not Check valves are fouled and
delivering the should be replaced.
correct flow rate
(continued)
The check valves should be
replaced on a regular basis,
depending on the usage and
type of solution or sample
pumped through the
pumphead. Refer to the
Maintenance section for more
information on how to replace
a check valve.
Liquid is continu- The pump’s piston seals are
ously leaking from worn or damaged.
the pumphead
washout drain
trough.
Erratic or reduced Columns packed with soft gels
flow rate when or large particles typically pro
pumping onto duce very low back-pressures
columns which when run at low flow rates.
produce low back-
pressures
(eg., Econo-Pac
®
cartridges or small,
agarose gel affinity
columns).
Loud or unusual Residue buildup behind
noise coming from piston seals.
the front of the
workstation.
Sticky pistons.
TROUBLESHOOTING MAINTENANCE AND TROUBLESHOOTING
12-4
5. Clean (or replace) the check valves (see
Section 11.3.3, Routine Maintenance of the
Workstation Pumps.)
a. Cleaning: Sonicate check valves in a warm
detergent solution, rinse with DI water, and
re-install.
Replacing: Replace badly clogged or
damaged check valves.
b. Recalibrate the pumps after
cleaning/replacing check valves. Select
Gradient Pump Calibration from the
Utilities drop-down menu.
1. Replace the piston seals on both pumpheads.
Clean pistons and piston guides with water,
followed by methanol as a precautionary
maintenance step.
2. Recalibrate the pumps after changing seals by
selecting Gradient Pump Calibration from the
Utilities drop-down menu.
1. Insert the backpressure regulator between the
pump and the injection valve.
CAUTION: Low-pressure columns may burst
if the backpressure regulator is placed after
the column.
1. The pistons should be rinsed on a nightly basis.
This may easily be done automatically by
programming a water rinse step at the end of
each protocol. This may also be done manually
by washing the pistons with the syringe
provided in the Fittings kit.
2. Follow the maintenance procedure to carefully
remove and disassemble the pumpheads.
Wash the pistons thoroughly with water to
remov debris or salt crystals. If the piston seals
have many hours of use, they should be
replaced following the information in the
maintenance section. Ater re-assembly of the
pumpheads, pump 100 ml of 100% methanol
(MeOH) through each pumphead at 5 ml/min
with the 40 psi backpressure regulator in place.