how would I go about checking and adjusting the main relief valve pressure, the machine is coming up on its 1000 hour service, craining operation seems a little weak
You're going to have to be more specific with a Serial Number. There are too many different models of 305E2 to guess which one you have.
cat0305eah5m08613
See attachment.
is illustration number two looking at the back of the pump
The valve should be this one I think.
great, thank you sir