Hydro pump Shaft cylinder block removal

[Petes Horse 20]

Hello all, Figured I would share some info. I had to disassemble my d160 hydro pump motor and don't have a press.

I also had no idea how far to press the shaft or how much force to use.

I ended up using my small drill press to compress the spring and hold pressure downward on the shaft while i tapped down on the pump body with a rubber mallet.

It popped with very little force. I think tapping it helped the most. Make sure to put a socket or something for the other side of the shaft to move into.

Thanks, Pete

[Petes Horse 20]

 Doesn't look too bad. 

[daveoman1966 3,762]

I can see lots of scratches and scarring on the brass-surface parts.  you MUST get the surfaces as smooth as possilble, using 220 400 600 progressive grit sandpaper on a FLAT surface.  All 9 pistons and the valve plate....as well as the BASE of the cylinder block need refinished. 

Parts should look like this: 

Edited October 14, 2017 by daveoman1966

[Petes Horse 20]

Thanks for the pics. it helps to have a reference. I managed to slowly sand off a few finger tips but i think I got it.

 

The first picture the plate looks like steel but it's still brass.

 

[daveoman1966 3,762]

The base of the cylinder block looks ok.  HOWEVER...  the VALVE PLATE needs work...lots of it.  You must continue to sand out the circular gouge using 220 grit paper on a FLAT SURFACE plate.  If you don't hot oil will simply bypass thru the gouge, detrimental to oil pressure, resulting in loss of power.