how much gas do i need to put in my blazer k5, 90, 5.7L A/C system?

 

If by gas you mean R12 (what it was originally filled with) or R134a (if it has been converted), it is 1,463kg (3lbs 2oz).

 

My 90 pick up takes 2lbs 2 oz but might be different in a k5. There should be a sticker under the hood. But its probably worn off

 

When they changed body style, the system capacity dropped. I took the info from my 90 R/V FSM.

 

sorry i forgot to mention - it's R134a

 

instead of opening a new thread i'll ask it here - it's all on the same installment.
when i tried to install the accumulator i noticed that when i bolt the nut from the evaporator to the accumulator, all the way in with an o-ring of course, the accumulator wobbles on the tube.
and i don't remember how it was when i removed it, but i guess the accumulator needs to sit tight in order to be air tight, right?

 

It should be supported... (i.e. not flopping around)

So it doesn't tighten up when you tighten the lines?