That time of year: educate me on recharging A/C

Yep, I know that needing a recharge means the refrigerant is leaking out, which is an indication of a larger problem. But my better half's '00 Focus needed a shot a couple seasons ago, and it only just now needs a recharge, so I think the problem is pretty minimal.

Now, I've watched a pretty good YouTube tutorial on this so I'm not completely ignorant, but I've never done any service to a vehicle AC system. I'm mainly concerned with the possibility of overcharging. Is there a good DIY way to do this that doesn't involve buying pressure gauges? Money's tight, so new tools aren't an expense I can swing at the moment.

Teach me about the intricacies of the recharge process.

Follow the instructions on the can. I've never had any problems.

I think the parts stores rent gauges, though for best results, it should be charged by weight.

Worth popping for one of the cans with the hose and a dubious gauge attached?

In reply to alex:

No, they are junk. Every plastic charge hose I've ever bought failed. Buy a decent one with brass fittings and it will last forever.

If you have a Ollie's Bargains close buy, they are selling R134 for $6.88 a can.

What ever you do, don't install any can that says "sealant" in it unless the next step for the car is the junkyard. No Pro will work on your system again if it tests positive for that stuff.

Adding on to what shuttlepilot said, I have also heard that at least some of the systems it will outright ruin (like my Saturn's). Sadly, the majority of the stuff that many auto parts places sell has the sealant in it. I sprung for an inexpensive but reasonably sturdy fill hose a few years back and it has worked quite well the few times I've had to recharge the Saturn.

Another source for cheap R134 is Big Lots- they have straight (no sealant) cans of R134 fairly cheap, and I stocked up on one of the 20% off days.

I just went through this. The plastic gauge assembly I had before was apparently for use with only that company's R134 cans so I bought a new gauge setup from Advance for $15 after coupon. Then, 1 can of the $10 stuff from wally world and my AC is ice cold again.

As far as the sealant stuff goes, has anyone found a can with the dye but not the sealant? I wanted to put some of the dye in my system because I assume there is some sort of small leak somewhere but every single can with the dye also had the sealant in it.

Enyar wrote: As far as the sealant stuff goes, has anyone found a can with the dye but not the sealant? I wanted to put some of the dye in my system because I assume there is some sort of small leak somewhere but every single can with the dye also had the sealant in it.

I know I found a can of refrigerant with dye at Autozone when I was initially trying to diagnose my system's issues...

Ashyukun wrote:

Enyar wrote: As far as the sealant stuff goes, has anyone found a can with the dye but not the sealant? I wanted to put some of the dye in my system because I assume there is some sort of small leak somewhere but every single can with the dye also had the sealant in it.

I know I found a can of refrigerant with dye at Autozone when I was initially trying to diagnose my system's issues...

Just read the labels. Don't forget about compatible refrigerant oil either!!

alex wrote: Worth popping for one of the cans with the hose and a dubious gauge attached?

I've never had an issue with them. And I'm the one who ends up having to charge peoples AC, what with the training and all.

Ok, Not to hyjack, but more just a add on question: I recently did a major repair and my AC system was opened. Can I refill in this manner? Or is a shop service required?

BobOfTheFuture wrote: Ok, Not to hyjack, but more just a add on question: I recently did a major repair and my AC system was opened. Can I refill in this manner? Or is a shop service required?

Well.............. It depends.

How long was it open?
And was it left open?
Did you vacuum the system?

If no, to the last 2 questions, no. If longer than just a few minutes to the first and no to the second, you need to put a accumulator/drier on it. Then you need to vacuum the system down and recharge with the proper charge and oil.

If you have the time check with the Auto Department of a local Community College. I have had my AC fixed a couple of times this way. Here at least all you pay for are any parts they need to fix the issue, the lab fees of the students cover the refrigerant and oil.

In reply to Rusted_Busted_Spit:

Check with the HVAC class as well. We had all the scales, vacuum pumps, nitrogen and all to really get your ac working great.

Did it all the time while I was there.

It was an accident, the accumulator got ripped open and replaced after a few weeks of gathering parts. Off to the local college, Then...

In reply to Grizz:

Cool, Ihad not thought of that. The only upside (maybe) of the auto class is they do all the work.

In reply to Rusted_Busted_Spit: So did the HVAC class. It's essentially the same system as an outdoor unit, so it's all learning/practice there.

I've used the can with the hose and gauge and had it work fine. Get the kind with dye in it and you can find the leak if it gets bad enough to make it worth the trouble. My MR2 just needed new O Rings at the compressor and the dye make it easy to find. I'd never done any AC work either, but it was pretty straightforward. Though after the repair, I did use a gauge manifold and Harbor Freight vacuum pump to evacuate the system and verify it wasn't leaking before I recharged.