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[email protected] stans4@prolynx.com is offline
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Default Anyone rebuilt a gear pump?

On Jan 6, 5:05*pm, Jim Wilkins wrote:
I'm trying to fix a worn Parker D17AA2A hydraulic gear pump for my
tractor. As bought (for $20) the max pressure was less than 200 PSI. I
found the aluminum end plate opposite the shaft worn away 0.010" by
the gears. The bronze plate on the shaft end looks pretty good(???).

I milled the end plate smooth, routed the O ring groove deeper and
shortened the gears by about 0.0007" with fine sandpaper, so the shaft
still turns by hand when I bolt the housing together. A sandpaper
donut removes close to 0.0001" when squeezed between the endplate and
the spinning gear, in the mill.

Does that sound right? This sleeve-bearing pump only needs to work
until I make and harden another involute splined broach to fit a new
steel pulley onto my other pump.

jsw


Air-cooled VW oil pumps are quite the same, although not nearly as
high pressure. What you've outlined is the basic overhaul for one.
Remove grooves from the end plate, make the housing zero-clearance
with the gears endwise and shim the cover with a gasket to get free
running. If the gears are chewed up, replace with a new set. If the
housing is chewed up, replace the pump. The way most guys did the
gears and housing was to get a sheet of fine wet-or-dry, put it on a
flat surface, a table saw would do, and sand until the gears and
housing had the same pattern of scratches. Done. I've built a couple
of new ones this way with no problems.

As the other poster said, check your shaft and bushing for wear, same
with gears. I suppose you could bore and sleeve the shaft bearing
with an under-sided sleeve and maybe grind the drive shaft down, but
how much time do you want to spend on what's really a fungible item?

Stan