AC recharge

[Jimmy9190]

I was in an accident about 5 weeks ago. Had to get a new AC condenser, radiator and other parts. Now that I have my truck back, the AC is not quite as cold as before. It is cold enough to be comfortable on a hot day, but not like it was before. Before the wreck, when I started my truck and turned the AC on, after about 5 or 6 minutes of driving I had to turn the temp selector up because my ears would be freezing. Now it stays on max cold all the time and the only time I increase the temp is in the morning when it's not so hot out. AC does not seem to cool as well when driving at slower speeds around town either.

I am thinking the body shop charged the AC but did not use quite the same amount of refrigerant as I had in the system before the wreck. I wonder if I could get one of those AC recharge canisters with the hose and gauge and top off the refrigerant on the low side of the system and have it work better? Any info on it is very much appreciated, I sure don't want to ruin my AC system.

Taking the truck back to the body shop is not really an option. I can't take the time off work to go there and I already had to make them replace the cheesy aftermarket front grille they used with an OEM grille, and I don't think they were real happy about that. I think they would probably say the AC is cold enough and refuse to do anything else with it. I'd rather just get the AC system topped off (if that will work) and not have to see that body shop again.

Thanks for any help here.

 

[JHZR2]

first thing to do is ge a set of good gauges on there and see what is up. I bet overcharged.

 

[stranger706]

Hopefully we have some AC guys that can chime in. I have some limited knowledge about it.

Your AC system may be over-charged just as easily as it can be under-charged. There is a range of pressure that is optimal for AC performance, it is not one specific number.

You can get a low pressure gauge (one that plugs into the "low side" of your AC system) from Walmart or any auto store, and that will give you a "rough idea" if your system is over or under charged. If its obviously under charged, you can buy the small cans of R134 and add a small amount at a time. Very easy to do.

However for accurate readings, both low and high pressure gauges are needed as well as running the engine at a certain rpm and amount of time; for this you would need to take it to a mechanic.

 

[brianl703]

You may also have air in the system. If that is the case, you have to put a vacuum on the system to get it out.

 

[Trav]

As the truck was in for body repair i assume the took the AC Condenser out and left it out until the repairs were complete.

They should have replaced the accumulator/Receiver-Dryer at this time and also added a small amount of the correct oil to the system (IIRC 2 oz usually for condenser replacement and 1 oz for the accumulator/Receiver-Dryer)then vacuum the system down and refill.

IMO you have 2 real options.

Check the Accumulator/Receiver-Dryer and if its old buy a new one with a low end gauge set and inexpensive vacuum pump (providing you own a compressor)from say HF
A small can of the correct oil and refrigerant and do the job myself.

Take it in to a A/C shop for a proper refill and service.

If the accumulator/Receiver-Dryer looks old you can bet they just threw a new condenser in and refilled it,if its new then they may have either done the job right or farmed out the job after repairs.
Call and ask them?
Without knowing this is all a guessing game but just adjusting of the refrigerant level IMO could be asking for trouble,the rest of the system may take damage which could could big $$.

PS The truck may use an accumulator or Receiver-Dryer depending on the system but not both.

 

[jorton]

Originally Posted By: stranger706
However for accurate readings, both low and high pressure gauges are needed as well as running the engine at a certain rpm and amount of time; for this you would need to take it to a mechanic.


AC comes second nature to these guys at full service shops. When I had a broken wire I overcharged the system with one of those re-charge bottles from AZ. Would have saved money if I'd just taken the car to the shop, first.

 

[Jimmy9190]

Thanks for the replies. I am headed out now to a shop down the street now that is adverising a "Free AC Check". I wonder how much they will try to charge for the free service.

 

[mechtech2]

Odds are that they'll find something wrong. Otherwise they would be out of business.
But you may simply be overcharged right now - a little over makes a big difference with R-134a. Undercharged is of course the other easy fix.
It's hard to believe they would not evacuate a system before charging it, but it's possible .

 

[Jimmy9190]

At the shop the outside temp here is close to 90 degrees today. On the AC gauges my truck had 40 on the low side and 240 on the high side. That is supposed to be within range. The tech evacuated my AC system, it had 1.92 pounds of refrigerant, the spec for the truck is 1.875. That may or may not have damaged the AC system, I don't know enough about it to be sure.

The valve for the high side AC line had a leak. It may have been a very small leak at first but it was really spewing when the tech took the coupler from the AC charging machine off. The shop was very cool about everything and they charged me $40.00 to evacuate and recharge the system and $20.00 for a new valve. The tech dialed it in and put back in 1.88 pounds of refrigerant. The AC seems to be cooling better now, but I realy need to go on a longer test drive, but wanted to get back home and finish what I am doing to my truck today. The shop is literally 3 blocks down the street from my house. The shop manager was one of the most genuinely nicest people I have ever met in a garage; he was kind of a character, an old biker-type, just out to make an honest living and not rip people off. He even gave me half a can of evaporator deodorant foam to use after I had been talking to him about BG Frigi-Fresh. This shop is a BG shop but they don't use Frigi-Fresh, they use a mold and fungus cleaner/AC deodorant that sprays up into the evaporator through the HVAC drain tube. He told me how to use it and said they get it from Napa, about $20.00 a can.

I am submitting the bill for this AC service and the bill for the leak detection pump and emissions hoses I bought last weekend to Allstate, so maybe they will reimburse me for them.

Thanks for all the help here. I don't know much at all about AC systems but am learning..