It is the pump, but the more pressure you add here the more likley you can blow the power steering seals, lines and pump.
Here is a mod you can do to a standard pump this is a chevy example but the toy one will be similar from memory, this helps at lower rev's at higher revs you may loose some feel.
http://westtexasoffroad.homestead.com/p ... ering.html
Good luck, and I am sure Sadam will probibly give this a go and see what results he gets if he still has the old power steering pump.
