And better get a good HOW-TO repair and maintain your Automotive AC system as well.
On my top 10 ten list of DIY failures one of them is those servicing their own AC Systems.
AC Recharge Kits
- Thread starter BMW Dom
- Start date
- Status
On my top 10 ten list of DIY failures one of them is those servicing their own AC Systems.
You seem like a competent DIY,
You may also once in a while when you wash your vehicle to spray some good soapy suds on the condenser and rinse it well. Less mentioned on forums is radiators and condensers will get a film that causes them to slowly become less efficient. Although it is so small most would say "REALLY DUDE" roll there eyes and disregard me. I am use to it. LOL
My buddy charged his Subaru AC with one last month, it was low on refrigerant and short cycling. The gauge on the can apparently wasn't reading right, and you're only seeing low side pressure, so you have no idea what the high side pressure is, and you can't properly diagnose problems reading only side. He emptied the contents of the can, heard a loud pop which came from behind the AC clutch. That cost him a compressor. Not the first time I heard of someone hosing an AC system with this type of a setup. But hey they have plenty of happy customers.
Autozone will loan-a-tool lots of A/C service tools
You can borrow a uv leak detector kit from AutoZone. It comes with an injector for dye, but most systems these days come with dye.
You can borrow a uv leak detector kit from AutoZone. It comes with an injector for dye, but most systems these days come with dye.
The gauges on the can are not that great, you also have take into account, the outside temperature. I have a set of HVAC gauges , but if didn't and was sure i was low on refrigerant and wanted to add more without a high side gauge, i would do this.
Pick a hot sunny day.
Have someone else in the car.
Crank it up and set the A/C on max fan full blast.
Attach the adapter to a refrigerant can,( WITHOUT SEALER) Purge the air out before connecting and quickly connect.
Add refrigerant with the can right side up as not to slug the compressor.
Let go of the trigger as soon as the person in the car feels good cool air coming from the vents.
Leave the can an hose connected and put a thermometer in the vent.
If you have 40F-45F Stop.
The above would work if you know you are low, i.e. the compressor is rapid cycling.
IF you are already overcharged the above method will not work.
Gauges are a much better way to judge if you are low on refrigerant.
Pick a hot sunny day.
Have someone else in the car.
Crank it up and set the A/C on max fan full blast.
Attach the adapter to a refrigerant can,( WITHOUT SEALER) Purge the air out before connecting and quickly connect.
Add refrigerant with the can right side up as not to slug the compressor.
Let go of the trigger as soon as the person in the car feels good cool air coming from the vents.
Leave the can an hose connected and put a thermometer in the vent.
If you have 40F-45F Stop.
The above would work if you know you are low, i.e. the compressor is rapid cycling.
IF you are already overcharged the above method will not work.
Gauges are a much better way to judge if you are low on refrigerant.
Last edited:
It's probably a leaky evaporator. But there's a long list of potential problems that this will do nothing to resolve.
By the way this is an "always on" compressor. The stroke length changes but it's always spinning.
By the way this is an "always on" compressor. The stroke length changes but it's always spinning.
- Joined
- Sep 21, 2020
- Messages
- 452
This!
Most people only rely on the low side guage but you will be able to do a much better job if you buy a little digital probe thermometer
place the probe into the left center vent at least three inches into the duct.. If the ambient outside temp is about 90 F and humidity is around 50%you should look for a vent temp of about 39-44 F. Monitor the low pressure gauge as well, but you want to aim for those temps 44 F is totally acceptable on a less than perfectly operating system, while adding refrigerant stop when you see the gauge hit 44 PSI or the temp gets to
44 F. That's a general ballpark for most vehicles that use r134a. Also you can check the suction line (large metal lines which are the same one you are adding refrigerant to. Is it cold and sweating at that ambient temp I mentioned, the line should be cold and sweating almost up to the compressor, BUT THE COMPRESSOR SHOULD NOT BE SWEATING OR COLD, if it is you are probably overcharged and high pressure could cause an early failure various components.
That's $140.00! Ouch. 1234yf is expensive!
- Joined
- Sep 21, 2020
- Messages
- 452
It depends on the specific situation. If you have a TINY leak, you won't lose much oil to become a problem. I have a leak in the discharge hose
and the seal points upwards so the loss of oil is almost nothing at all. Literally a drop or two a year if that. If need be I can get one of those small cans with PAG 46 oil and just add 1/4 oz from that
It's actually gone way down. It was $100 a lb my cost 2 years ago.
What fan speed and recirc on or off?
@Chris142 Quote:
If he was losing refrigerant he was losing oil. Just like an engine. No oil and things blow up
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
That's true, if there was no oil from a big rapid leak or a blown hose or seal, but not when it comes to slow leaks. In the case of slow leaks there's more than enough oil in the system or every car low on a charge would blow up their AC compressor using one of these AC top up kits. All systems eventually lose their charge, through hoses, connections etc. Some sooner than others, which is why these products are so successful. His car took years before it needed a top up, and had no indication there was a leak, there was plenty of oil in the system before he charged it up.
@Snowflake White nailed it.
Edit to add: I have another buddy use one to charge up his VW. He set the gauge to the ambient temperature range on the little dial. He ended up blowing air warmer than when he started. He called me to ask what I thought. I said stop, you might be overcharged. Sure enough he was overcharged, not good. I suggested he bring it to a shop have them evacuate it, and charge it the right way, by weight. Problem solved for him.
If he was losing refrigerant he was losing oil. Just like an engine. No oil and things blow up
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
That's true, if there was no oil from a big rapid leak or a blown hose or seal, but not when it comes to slow leaks. In the case of slow leaks there's more than enough oil in the system or every car low on a charge would blow up their AC compressor using one of these AC top up kits. All systems eventually lose their charge, through hoses, connections etc. Some sooner than others, which is why these products are so successful. His car took years before it needed a top up, and had no indication there was a leak, there was plenty of oil in the system before he charged it up.
@Snowflake White nailed it.
Edit to add: I have another buddy use one to charge up his VW. He set the gauge to the ambient temperature range on the little dial. He ended up blowing air warmer than when he started. He called me to ask what I thought. I said stop, you might be overcharged. Sure enough he was overcharged, not good. I suggested he bring it to a shop have them evacuate it, and charge it the right way, by weight. Problem solved for him.
Last edited:
Pro's use a sniffer. Using dye can take time to detect.
Last edited:
Its not that simple although I guess they would like you to think so as they want you to buy their product.
Why b/c you don't have a gauge on the high pressure side like is being discussed here? I needed some charge, this worked. It's a bandaid.
Well first because the leak (if any) should be repaired. Dumping R134a into the atmosphere through a leak is not good for the environment. And the proper way is to evacuate it and fill by weight.
- Status
