3-Point Hitch Lift arms will not lower

[8men]

I just replace the hydraulic pump in my TO35. The only replacement available is used on the later mode/serial number Massey's Original was P/N 183005M91 replaced with P?N 184473M93.
There were no problems with the exchange, except picking up the cover as it is heavy.
Started the tractor and the lift arms went up nicely. Set the control to down and nothing happened. Moved the control and still nothing happened. Turned off engine and the lift arms stayed up.
Took off side cover and moved arms and control valve, nothing happened.
My guess is the control valve is defective. Anybody have suggestions before I take the pump out and send it back to where I purchased it.

 

[murphy1244]

Maybe just maybe you locked up the adjustable rate control between your legs on the OP platform.

 

[8men]

Murph, Thanks for the quick reply. The Massey Ferguson TO35 doesn't have an adjustable rate control on the lift cover, I just have the operational and draft control on the quadrant to the right of the seat.

Thanks, Jim

 

[Backwoods Welding]

Mine does this when I pull the position control lever too far back. The linkage on the top cover falls out of place and binds up not letting it drop but when it does work free it will drop and not work at all. It's hard to explain but it is a forked piece that sits around a roller. You might have to take the top off and look at it. I can fix mine from the inspection cover but I have done it a time or two. Did you pull the lever past the word "up"?

 

[8men]

Thanks Backwoods for the suggestion. No, that would have been easy and this past week not much has been that way. I ended up taking the pump out and sent it back to All State Ag Parts for replacement. Now-a-days many of the parts for our old tractors are made in China or India and I'm afraid the quality is not as good as the original parts. And in some cases not as good as the worn out parts they are replacing.
There really was only one possible problem and that was the control valve. By carefully removing the auxiliary valve plate on top of the cover and relieving the pressure in the system, the arms dropped. I post the results of the next pump after it is installed.

 

[Backwoods Welding]

I just bought a pump for mine from reliable aftermarket parts inc on eBay. It works perfect.

 

[billyinvt]

This sounds like the problem I am currently having. Does anyone know where I can get pictures of what I'm looking for when I take the inspection cover off?