PPCH™ OPERATION AND MAINTENANCE MANUAL
© 2009 DH Instruments, a Fluke Company
Page 158
5.10.4
PUMP INLET FILTER (LIQUID) REPLACEMENT
PRINCIPLE
The pump inlet filter is intended to protect the pump and the PPCH from contamination in the
oil drawn from the PPCH reservoir by the pump. The filter is between the PPCH internal
reservoir and the pump. The filter may become clogged with contaminants over time
preventing adequate oil flow and causing the pump to be starved for hydraulic fluid. The
symptom of a starved pump is rapid cycling without generating pressure. The pump filter
should be replaced or cleaned by flushing as part of PPCH preventive maintenance or when
symptoms of clogging are observed.
PROCEDURE
To replace the inlet filter (liquid), proceed as follows:
Vent the PPCH and disconnect electrical power and
drive air supply.
Close the reservoir
FILL/DRAIN
valve on the PPCH
rear panel.
Open PPCH chassis to gain access to the mechanical
module (see Section 5.9 for instructions).
If the PPCH is a single Q-RPT or utility sensor (no Lo
Q-RPT), the filter can be accessed through the top of
the PPCH chassis.
If the PPCH has a Lo Q-RPT, the PPCH must be placed
on its side so that the bottom of the mechanical module
is facing you.
Looking at the PPCH from the rear, place the PPCH on
its RIGHT side to avoid draining fluid from the reservoir.
When turning the PPCH on its side, do so carefully
supporting the chassis and main body and the
mechanical drawer to avoiding damaging the slide rails.
Using 9/16 in. and 1 in. wrenches, loosen both sides
of the pump filter. NOTE DIRECTION OF EXISTING
FILTER!
Remove filter.
Install new filter
Units built prior to December 2008 will require filter
kit p/n 3401429 which includes replacement filter and a
pre-attached extension tube to compensate for difference
in filter length. Units built later will require only the filter p/n
3138000 (102808) (see Step 5).
Tighten fittings.
If the PPCH has a Lo Q-RPT, set the system back to
a normal position. Reconnect electrical power and
drive air. Power up the PPCH.
Perform pump prime procedure (see Section 5.10.1).
Check filter connections for leaks.
Open
reservoir
FILL/DRAIN
valve.
Close PPCH chassis (see Section 5.9).
Previous Pump Supply Filter P/N
3068879 (103727)
New Pump Supply Filter P/N
3138000 (102808)
Step 5
