Model 640 & 640CC Instruction Manual
D01206676
Revision A February 2016
40
13
Troubleshooting
The following section consists of a table listing possible remedies for the most
common consistometer problems.
Table 13-1 Troubleshooting Model 640 & 640 CC
Symptom
Cause(s)
Remedy
System builds pressure but
will not hold pressure
Leak
Check fittings for leaks and
tighten fittings. Heater
ferrules, contact pins, and
magnetic drive housing are
also possibilities.
PRESSURE RELEASE
and AIR TO CYLINDER
valves are not closed
tightly
Close valves tightly.
PRESSURE RELEASE
or AIR TO CYLINDER
valves worn out.
Replace valve stem or entire
valve. PRESSURE
RELEASE valve is most
likely to wear out.
System builds pressure and
oil runs out between pressure
vessel and top plug.
Metal o-ring (C-0061) is
scratched or dented.
Replace o-ring.
O-ring sealing surfaces
and/or seal shaft are
worn, pitted, or scratched.
Lap o-ring sealing surfaces.
Pump strokes but little or no
pressure is obtained.
Valve open, severe leak,
blown rupture disc.
Locate problem and correct.
Pressure vessel has
trapped air.
Open thermocouple connector
slightly and release trapped
air.
Oil reservoir is empty
Fill reservoir with oil
OIL SUPPLY valve is
closed (dual
consistometer only)
Open OIL SUPPLY valve.
AIR SUPPLY valve not
opened or air not
connected to instrument.
Connect air supply and open
AIR SUPPLY valve.
Severely clogged low-
pressure filter.
Replace low-pressure filter
element.
Faulty pump check valve.
Clean and/or overhaul pump
outlet check valve.
No air supplied to air
operated valve (if so
equipped).
Check air lines leading to
valve. Check valve solenoid
valve. Restore air supply.
Pump builds and maintains
pressure to a certain level
than then stops.
If not oil is coming from
pump muffler, oil
reservoir ran dry.
Add oil to reservoir.
If oil is coming from
Overhaul or replace pump.
