General AC Recharge Questions

[Jimmy]

2001 Honda Accord LX with 144K miles (wife’s car)

In the beginning of the summer my wife was complaining of the AC not blowing as cold as it used to, and now it’s practically blowing warm air. I can see the compressor clutch engage, and verified it’s not completely dry by blipping the schrader valve on the high side. I assume the compressor would not kick in if it was dry. Also performed a visual inspection of the condenser and did not notice any cracks… lots of tiny dead bugs though! :cheer:

There might be a small leak, but I am not sure where it is, so want to start with recharging the system with dye. I’ve watched a few of ETCG’s AC videos regarding recharges, and was initially planning for a full evacuate + recharge. After watching the recent one where Eric performs a small recharge on his Integra GS-R, I am now leaning towards that as my first step. I’ve gone ahead and purchased a vacuum pump, manifold gauges, R134a refrigerant, dye, and PAG 46 oil.

My questions are:
1. When adding dye to the system in the yellow hose, how do I purge the air out of the hose without getting dye everywhere? Or will the refrigerant (being thinner than oil) sort of move ahead the oil and get purged first? Hopefully I’m explaining that correctly.
2. Assuming I am not replacing any parts (compressor, condenser, etc.), if a shop evacuates the existing refrigerant, do I need to add oil back to the system? Based on some Internet research some people recommend no oil should be added, some say “get the R134 cans with the oil”, some say we need to measure how much oil was taken out and add that amount exactly.

Thanks,
Jimmy

Topic

[college man]

I would not add any oil. Get refrigerant with the dye in it. When the gauges are hooked up
to the hi and low sides and the charging hose is on the can of refrigerant/dye crack the low
side port on the manifold set. this will put refrigerant up to the charge hose can valve. Purge
slightly. then start your recharge.

[Rob]

if you have no pressure I would replace all the o-rings… and check the condencer or the evaperator I forget which one it is …. the part in front of the car next to the ratator… and see if it has any damage…. lookinfg at the fins….
dont forget to oil your o-rings and make sure you get ac o-rings should be green in color…
you might also want to replace the valve stems if you want to at this time… then I would do a vacuum check…. and see if it holds vacuum for 30 mins… if it does… I would go about charging the system with oil and dye and stuff and see how it works… because about 70% of the its the grill or the o-rings that are bad… so if you have no pressure its a perfect time

[Andrew Harris]

Just one note on the oil thing. The oil is carried by the refridgerant. So if you do not fix the leak and you keep having to add refridgerant over and over again and dont add any oil back eventually the system will become low on oil and could damage the compressor. It should be fine not to add oil the first time.

[Ole Eggers]

I find it amazing, that you guys (America in general) fiddle around with A/C systems like it´s nothing. The coolant is both toxic and bad to got out in the atmosphere and yet you can buy it in any convenience store like chips or rice pudding.

Many here talks about using coolant to check for leaks, which means they are venting it, until they find the leak. Or just keeps filling up.

You know, here in Denmark, you have to be bloody certified to work with that stuff and you have to show your certificate to be able to buy the damn coolant.

Some here talks about evacuating the system, but into what ? I don´t see any pick up canisters in the kits you can get off Ebay. So you just suck the coolant out and vent it ?

Test for leaks with vacuum and nitrogen. NOT with coolant !! Even compressed air can do it, if you have taken the water out.

[Greg]

[quote=”Iznogood” post=174241]I find it amazing, that you guys (America in general) fiddle around with A/C systems like it´s nothing. The coolant is both toxic and bad to got out in the atmosphere and yet you can buy it in any convenience store like chips or rice pudding.

Many here talks about using coolant to check for leaks, which means they are venting it, until they find the leak. Or just keeps filling up.

You know, here in Denmark, you have to be bloody certified to work with that stuff and you have to show your certificate to be able to buy the damn coolant.

Some here talks about evacuating the system, but into what ? I don´t see any pick up canisters in the kits you can get off Ebay. So you just suck the coolant out and vent it ?

Test for leaks with vacuum and nitrogen. NOT with coolant !! Even compressed air can do it, if you have taken the water out.[/quote]

I couldn’t agree with you more. As a technician I also have to be certified to work on AC systems and if I were to vent to the atmosphere I would be heavily fined if caught doing that. I wish that auto parts stores couldn’t sell refrigerant either although I do make good money when one of those charge it home kits causes major damage from improper use. This is one area of repair that I do not offer advice or instruction on to for the DIY person.

[Jimmy]

I purchased a 12 oz can of R134a + dye last Wednesday, and got everything attached through the manifold. I struggled a bit with the yellow fill hose – couldn’t figure out why it wasn’t sending any refrigerant into the manifold – turns out I had to unscrew the little things inside the hose that push in the schrader valves. Part of learning new tools I guess 🙂

I started out with low side at 35, then highs around 70-75. I added refrigerant a few seconds at a time and saw the low side starting pulling vacuum. but did not notice any increase on the high side. Eventually added the entire 12oz can and now highs are still around 70-75. The A/C now cools a bit better, but not cold. Ambient temps in garage around 60F, temps on vent around 49-50F.

I purchased a 2nd can of r134a with the dye, started adding a bit more. Got about 1-1..5 oz in and still no improvement on the high side, and the compressor is cycling on and off. About 15 seconds on, then 10 seconds off. Here are the readings when off and on. When holding the throttle at about 1500-1800, the high side doesn’t get much better, maybe hitting 77.

On:

Off:

After a bit of Googling, this seems to indicate there is air or moisture in the system, and instead of adding refrigerant, I should get the system evacuated, boil off the moisture with a vacuum pump, and then go with a full charge. Is this the correct next step, or should I continue adding more refrigerant?

Thanks,
Jimmy

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