Anyone recharge their AC system?

[turboawd]

Looking through the TIS manuals, and i only see vacuum out freon and then fill by weight. Isn't there a recommended high and low pressure check?

[turboawd]

Connected the gauges and pressure readings were 20 low and 140 high. That seemed low to me. I added only a little freon and got to around 35 low and 180 high and seemed a lot cooler inside. Though it's evening now and 85f, and will test again when it's in 90s again.

[TOPEC]

Originally Posted by turboawd

Looking through the TIS manuals, and i only see vacuum out freon and then fill by weight. Isn't there a recommended high and low pressure check?

its telling u to fill by weight cause its assuming u to be pulling out all the old freon. just look up high and low pressure numbers online, it should be like any other automotive ac system, nothing special.

[turboawd]

Originally Posted by TOPEC

its telling u to fill by weight cause its assuming u to be pulling out all the old freon. just look up high and low pressure numbers online, it should be like any other automotive ac system, nothing special.

Don't the f15 x5 have variable ac compressor? I did check pressure with ac max on, so I assume the compressor would be at full capability.
And from looking at charts, they say at 85f the low side should be around 45 and high around 220. Not sure if bmw ac should be that high at idle. Driving around now again with temp outside saying 90 and it's keeping cool inside without having to use ac max. My x5 is 6 years old, so i assume a little freon leaked out over time.

[NERO X]

I'm an AC automotive engineer and guessing at charge level by using pressures on a variable displacement compressor is difficult. All AC systems leak, but a very small amount each year. 6 yrs should not be so low that you feel a difference in the cabin. My guess is that you have a leak. Best method is to to do a full refrigerant recovery, hold vacuum for an hour to see if it holds, then full recharge with leak detector dye and leak inspection at all the major joints. UV leak detector dye shows up with a UV flashlight. Mine X5 developed a leak in the evaporator around 50k miles and is hard to diagnose and costly to fix. Luckily was under extended warranty. AC work is hard DIY, because of the special equipment needed.

[turboawd]

Originally Posted by NERO X

I'm an AC automotive engineer and guessing at charge level by using pressures on a variable displacement compressor is difficult. All AC systems leak, but a very small amount each year. 6 yrs should not be so low that you feel a difference in the cabin. My guess is that you have a leak. Best method is to to do a full refrigerant recovery, hold vacuum for an hour to see if it holds, then full recharge with leak detector dye and leak inspection at all the major joints. UV leak detector dye shows up with a UV flashlight. Mine X5 developed a leak in the evaporator around 50k miles and is hard to diagnose and costly to fix. Luckily was under extended warranty. AC work is hard DIY, because of the special equipment needed.

Hi nero. Thanks for your input. Attached is a picture from the BMW tis information. Which can also be found here.
https://www.newtis.info/tisv2/a/en/f...eck/1VnYI6BJG5

Their freon loss chart only goes up to 5 years of age and says that at 5 years, up to 150 grams of freon can be lost. Am i reading that right? Up to a 1/3 of a pound?

[NERO X]

Yes, that is how the chart reads. All manufacturers take into account the annual estimated looses and build that into the total charge level that they fill with in production. I see that 675 g is the full charge, but this should take into account a certain amount of loss without a significant impact to AC performance. The max. 150 g at 5 yrs should not require filling to improve AC. Back to your original comments; I think it is likely you have a small leak and lost more than 150 g, so by topping off("adding a little"), you probably got it back closer to nomial level to feel AC improvement. But, if you do not know how much was in there to start and you don't know exactly how much you added, you're refrigerant level is completely unknown now. Over-filling a system can lead to compressor failure and other issues too, so ideally, you would have followed the instructions and evacuate the ref., put on vacuum, then filled to the measured full amount. It might be fine, or not; hard to say. Good luck.

[turboawd]

I really dont want to go thru whole process of draining and refilling. Even though I do have a vacuum. Lol.
I didn't add much like I said, so I think I'll be ok.....

[CatalinP]

I did it twice at the Dealer. One time on my request, as the car was 3 years old, and 2nd time due to evaporator compressor suction pipe replacement.

Both times it was done using empty - refill method.

[CatalinP]

bad post.