late HPOP test device build

Hydro said:

I am thinking that many of the "bad" pumps have suffered from the swashplate holder rotating in the bore -- the location affects the timing of the pistons and valve plate > then the pumps ability to move oil. Just a simple roll pin to locate that part would be a good fix

The brass valve plate in the pictures is junk -- those scratches connecting the valve ports are a killer in this style of pump -- the higher the pressure the pump is making, the worse the lifting affect is on the plates -- this causes the whole cylinder block to lift from the valve plate and spew oil from between the cylinder and valve plate , rather than deliver out the pressure port -- when the pressure called for is reduced, or the system is shut down, than the plates will come back into contact -- and pumping will seen normal again, until high pressure is reached -- the no or low pressure again as the plates separate

I have ran into this scenario many times with the machines I work on -- a pump will flow almost to spec at lower pressures but as the max is reached the flow drops off all of a sudden -- testing with gauges and a flow meter

Not the valve plate, it is keyed as you mention -- the problem is the "plug" which contains the swash plate, that is the part that is not keyed, in some / most of these pumps

Maybe that is not the best description, so here goes -- the part that contains the swash plate and rear bearing, has to be indexed to the valve plate, for the pump to work properly
this "plug" is just a press fit in the pumps I have seen -- A very poor design -- A locating pin or protrusion to lock that part would have been good

Reference Hartwig's post, the first picture -- the part the pistons are sitting in

late HPOP test device build

Hello Gentlemen, I would like to build a device to test second/late generation HPOPs. To see how they work I have started to disassemble a pump. Can anyone tell me how these inserts are fixed in the housing? I can't hammer them in, nor can I pull them out with an impact hammer.

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