Chevy & GMC Vans

i know this is the wrong section to post this in but everyone checks this section out the most. okay i am going to flush my power steering system by running new power steering fluid thrigh the reseror, unitl it was clean what line is the return and what is the supply? and what line should i disconnect to drain the old fluid and continu to drain while running until it is clean??

The big hoses with the crimped ends are the pressure hoses. The return line is the smaller hose.