I need to change two hoses on my OC4.
It there any procedure to minimize fluid loss?
Is there a procedure to bleed air after changing hoses?
Put a drip pan under the down hill end of the hose and lossen that end first. Then lossen the uphill end and let it drain into the pan. You're going to probably lose some anyway. No real science to it. Be creative!
I just bought 19 hoses to replace all of the ones on the OC-4 I'm restoring.
Not even going to mention what that cost
A lot of those old hoses on these machines have replaceable ends, so you can buy bulk hose and re-use the ends.
About bleeding the air out - don't worry about it, as it will bleed out as you use it.
Blake