On Jan 7, 4:40*pm, wrote:
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

Thanks. The end wear was all I saw, elsewhere the gears and shafts
have a mirror polish, including the other end which presses against a
bronze plate.

I can usually figure out how to make something broken work again, but
in this case I have no experience to predict how long it will hold up,
or how much clearance is right.

I have resleeved and bored a pump before, which taught me that the
play in the quill of my mill increases as it extends, IOW it bores a
slight taper. The knee feed fixed that.

jsw