Narrow frame Hydo-unit 12A74 manual
 

Does anyone have a manual for taking the pump apart? I have to replace the seal on the front and the spring that returns the control back to neutral?
Any help will be appreciated.

The pump for a hydrostatic drive?? Or the external hydraulic lift unit for the 122, 123, 1X4, and 1X5 series?

If you mean a hydrostatic drive pump, the only repair manual would be found in the service manual for your tractor. What model is your tractor? If you tell us we can direct you to the free PDF manual here on this site.

If you mean the external hyd. lift pump, I looked through the manuals here and did not see it, though I know I've read it before. Someone has the manual for it somewhere I'm sure.

We need more info on your machine if you want the hydro trans repair instructions

As for a manual to the external hyd. lift pump, I didn't find a manual but I found this website with repair instructions:
http://www.cubcadetman.com/cc/how-to...draulic-pumps/

If you need parts for one look here: https://www.ccspecialties.org/liftparts.html