Service Manual

HY13-1521-M2/US Service Manual
General Information Series HB Hydrostatic Transmission
Remove the cylinder block
Remove the snap ring from
the pump shaft with external
snap ring pliers. Use care
not to over-stretch snap ring.
Take special notice not to
scratch sealing zone on shaft
while removing and replacing
snap ring.
Remove spring retainer
Remove the spring retainer
and the cylinder block spring
from the shaft.
Remove the cylinder block
assembly
Inspect pistons, bores and
both running surfaces
Remove the cylinder block
from the pump shaft by
sliding the cylinder block off
the splines on the pump
shaft. It may be necessary
to rotate the cylinder block
by hand while lifting.
Check for excessive wear
Check surface of rotating
group and sides of pistons
for excessive wear, indicated
by scoring. Remove pistons
and check bores and springs
for signs of scoring. Check
top of OD of pistons for
pitting or scratch marks.
Parts must be replaced if the
scoring is deep enough to
catch a fingernail.
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Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee USA