IH 574 pto and hydro problems

[IH812]

I just picked up a 78 IH 574 with a 4 cylinder diesel that had a freeman 4000 loader and kelly 70 backhoe. The previous owner said the hydraulic pump was bad and after getting it home I replaced it. The tractor runs fine but now I'm not getting any power to the loader or backhoe along with the PTO not engaging. The power steering is working and I can get the 3-point hitch arms raise but that's all I can get out of it. I talked to the dealer and they said it was most likely the MCV valve being bad. If that's the case I can repair it but i want to know anyone else has had similar problems that weren't the MCV valve and something in depth I will just take it to the dealer and have them fix it.