AC Recharge

[bbeljefe]

The pressure is supposed to drop on the low side when the system is in use. What you're not seeing, because you don't have a manifold gauge on both service ports, is the rise in pressure on the high side. Nothing wrong with that but... if the label on the car says it takes 64 ounces, 20 ounces will cause the compressor to cycle. And, 64 ounces is four pounds so you're still way too low... even if the system wasn't leaking.

Which brings me to another point. If you're system ran out of refrigerant, you do have a leak. Refrigerant doesn't wear out and it doesn't evaporate. It either stays in the system or leaks out.

As far as the cost to repair it at a shop goes, you'd probably be able to buy a cheap vacuum pump, a set of R134 manifold gauges and four pounds of refrigerant for what the shop will charge in labor, depending on what's leaking, obviously. But just think of it this way, if you buy the tools and do the repairs yourself, you'll have the tools to do the next repair you have to do. And if you plan on living much longer and driving a vehicle with air conditioning, there will be a next repair. :-)

You can put a can of dye in the system and find the leak with a black light. And the dye won't damage the system, the manifold gauges or the vacuum pump.

[boom50cal]

Also don't use ANY refrigerant with all those oil and additives in it because when you take it to get a whole system recharge at a shop, they'll ask you if you have used stuff with additives in it and if it's yes, they'll refuse to do it. My brother works at a shop here and he said the additives with ruin their shops recharger.

Correct, don't do additives yourself. Incorrect, additives do not ruin rechargers. Most of the newer all in one rechargers pull all the remaining refrigerant, do a vacuum test, have programmable pressure points(as in you hit 2lbs 3lbs etc) and add oil to the systems as an option at the end of the cycle.

As for price, you'll be out $70-120 if you take it to a good shop. My dad is a service manager at a Ford Dealership and he charges around $80 for a AC Service. Ask if they have a "Summer Works" package, ie oil change, tire rotation, and AC service. My dad had a deal like that last summer for $130 for most vehicles, $150 for diesels. SOLD LIKE CRAZY.