[Farmall] 504 Utility

[Kevin Bish]

 Hello,
 does anyone know the grade of hydrauilc oil used in a 504 utility? I have a 
customer that just bought one, and wants to change all the oils and filters 
in it. I have a barrel of hydrauilc oil here, that is a ISO 68 weight. Is 
this to heavy for in the transmission,pto, and hydrauilc system for his 
tractor? I have tried to look up the specs for this tractor, but can't find 
anything on the internet. Thanks, Kevin.