Truck AC service question

I've done mine in my old truck. I over charged it by a little bit. No big deal. I just gassed a little off and good to go. The shop wanted to replace basically the whole system. That was not going to happen and it works fine now.

If you do it yourself my suggestion is to go slow. Put a bit in and drive it for a bit and check it out. Too low? Put a bit more in and drive it...………...

Using a little common sense can keep you from damaging pressures. I'm sure there are some that just hold the trigger until they can't get anymore freon in the system.

If it is a temporary fix, charge it yourself. No point in spending ~$120 knowing it's going to leak over the next couple months. If the charge will last till next summer, a can from Wal-Mart is a very appealing price.

I have used the little can before with no ill effects. Remember, if it is low it has a leak, you may make it work but it still has the leak.

K Charles wrote:
I have used the little can before with no ill effects. Remember, if it is low it has a leak, you may make it work but it still has the leak.

That's part of the dilemma, it's 16 y/o and slightly low (still works - kinda). I wonder if you can ask for much better than that. I suspect that if they went looking for a leak, it would be impossible to find if it took this long to get low.

$10 for a recharge can of refrigerant is a pretty cheap experiment before taking it in.
If it works for a while, you win. If it doesn't, you needed to take it in anyway.

I think some of those cans also have a sealant in them to aid in a leaky system in addition to the freon itself

Yes, do not get a can with sealant in it. top it off a little at a time. you are probably only 1/2 to 3/4 of a pound low if its still working as you say. It may work fine for a few years. If it were completely empty then I would just take it in.

I think topping it off will work for you!

After repeated visits to several "expert" shops, I bought the tools to do it myself. I would trade a vehicle before subjecting myself to that much abuse. It's a very long story, so I won't bore you with the details, but the AC business is pathetic.

I have used those cans and a low side gauge 100 times and it has never caused a single issue. If I find a leak in the system and have to replace a part then I have the tools to draw it down and I use a gauge set. I replaced the condenser in my wife's van a couple of weeks ago. It had a really bad leak. The van has front and rear air and take 40 ounces from empty. I drew it down and then added 40 ounces using those small cans. It works great. Working on an R134 system is super easy if you have the basic tools. As to the low side only gauges.. I think I have like 4 of them. The Ollies near me sells a low side gauge for like ten bucks. Get your R134 and it's an easy fix. If you have a leak you will be needing to fix that though. With that said, years ago we had an old Volvo V70 that had a leak in the evaporator core in the dash. That old car was a junker that I was trying to push as far as it would go. So, I bought the recharge with the good stop leak in it, not the cheap stuff. It worked for the two more years that we had it and was working great when we sold it. Keep in mind that a low system will cause a lot of cycling of the compressor clutch and will wear it out. Then a leak creates all kinds of unanticipated stressors on other parts. In some vehicles it will cause a chatter when the clutch is engaging that puts stress on the belt and tensioner (see some years of GM/GMC SUVs and trucks). So, keep the pressures right or don't turn it on till it's where it needs to be.

Thanks everyone for all the great information, it really helps! I also searched the interweb for stories about ruined compressors and the only "stories" I could find were written by shops. Actual users didn't seem to have any problem.

I went ahead and ordered a kit from Amazon.