Subaru Robin PKX201 - Manual (Page 37)

Centrifugal Pumps - PKX Service
- 37 -
34. Hand tighten the impeller onto the crankshaft. Make
sure it is threaded on all they way. If the impeller is
not threaded to the full extend, the impeller face could
strike against the inside of the volute.
35. To make sure the impeller is installed correctly, hold
the volute against the back plate and check
the clearance with a feeler gauge. If the clearance is
larger than 0.040 thousands of an inch then another
shim must be added.
If the clearance is 0.020 or less and the pump grinds
and turns over hard, it is possible that a shim needs to
be removed.
36. Re-tighten the impeller with a hard rubber mallet, hit-
ting the blades in a clockwise position. It should be
tight enough that you should not be able to turn it
loose by hand.
33. Re-install the shim(s) using the same number as
was taken off. If new components such
as impeller or volute was used, it may become
necessary to re-shim with new shims for proper
clearance.