I believe I have a CESSNA model K 20644 Hydraulic Pump that came on my 1957 FORD 800 Tractor that had a Sherman backhoe attachment. It has a FORD 701 front end loader.
I took the Name and numbers off the case. I am wondering if you might be able to help me determine the capacity and a replacement pump. The pump has two mounting holes on the flange at the shaft end and might be 4" on center or close there of. This was originally connected to the PTO thru a RPM increaser that failed 10 years ago and was moved to the front when the vane pump there failed. The only other numbers I could get off the case are as
follows:

#619 G 8 found on left side of case at the shaft end.
# K 20644 1CCD found on right side of case at shaft end.
#15147.17C3 found at right side of inlet outlet end of case.

If I could find out the capacity I believe I could find a replacement for this unit.
I have not taken it off yet s the tractor is still being used although minimally.
I thank you for any info and time you might be able to give me for this unit. This is a privately owned unit for personal use only.

Thanks again,
Roger Gleason

I can be reached at e-mail address roger.gleason@uconn.edu

Take a look at this page for a sizing formula when you know the Gear Diameter, Center Distance of Gears and Gear Width.

http://www.baumhydraulics.com/pumpsize.htm

I know I am probably too late with a reply but this is my first time to log on. I had some info on your Cessna pump and I believe the displacemnet is approximatelky 2.02 cu.in/rev.

This message has been edited. Last edited by: BillK,

2.02 cu.in./rev would equate to what in gpm &
pressure? I assume the rpm to be 1200 to 1400rpm.

cu.in./rev X rpm / 231cu.in./gal = gpm
therefore 2.02 x 1200 / 231 = 10.5 gpm
and at 1400 you'll have around 12.25 gpm

pressure unknown: pumps can just create flow, resistance to flow creates pressure

hp = gpm X psi / 1714 X % efficiency

note: using 1500 is a good rule-of-thumb for 85% efficiency

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