F40 Hyd. pump differences

[Cowcop]

Does anyone have any input on rebuilding an "early model" pump? Tractor is a '56 F40 I've had a bearing grenade in the center housing and debris was ground up and sucked through the pump. I never lost hyd. capability it just got weak. I tested the PSI (about 1250) and began to troubleshoot. Did all of the I&T book stuff, and didn't help much. Removed the pump and found some scoring and valve wear.
My question is that I am unable to find a straight replacement pump, all of my findings are to use the newer style replacement. Does anyone know about any rebuild parts for the early model, i.e. pistons, cylinders, and valves. I think the old pump p/n is 183500m91, .7990 pistons. I hate to buy the newer pump if I can redo this one.
Or better yet are there any backyard tricks for us cheap-os to do? I am afraid to hone the pump cylinders and smooth the pistons because to me there will be too much slop after doing that to help any.

[shona13]

G'day .
All the parts are available either after market or genuine,the early model f 40 did not come with a hydraulic filter but when rebuilding your original pump you can buy a filter kit ,it requires a hole to be drilled in the new filter housing to accomodate the control valve dowel pin,fitting this kit will eliminate the risk of unfiltered oil causing damage like you have had .
happy days.
Hutch.

[Cowcop]

Do you any info on where to find the old pump rebuild parts? I guess that is more my problem, the early pump parts do not seem available. I can find newer ones easy.