DIY AC R134a recharge writeup.

[SecretAznSauce]

As with all DIY writeups. Proceed at your own risk.

It was 85 degrees today, and the secretaznman, thats me, can't stand heat too well. So I proceeded in recharging the bimmer.

you will need r134a freon, hvac gauge and about 25 minutes

first remove the inlet caps. the big one on the left is the High side. the small one on the right is the low side. Use ONLY the low side to charge with.


<BR><BR><img src="http://www.dynamicautoworkz.com/cars/BMW%20325i/ac%20recahrge/142-4214_IMG.JPG"><BR><BR><BR><BR>See what your current charge is. Start your can on and turn the ac to max. Also note your engine needs to be at normal operating temperature.<BR><BR><BR><img src="http://www.dynamicautoworkz.com/cars/BMW%20325i/ac%20recahrge/142-4216_IMG.JPG"><BR><BR><BR>An over charged systems can also not cool. attach your gauge to the low side and then the high side, you should be around 25-35 psi on the low side and 160 - 185 psi on the high side. mine was around 20 psi and 140 psi.<BR><BR><BR>attach the freon can to the valve and attach to low side inlet. slowly open can and you should feel the can getting cold. this means the compressor is sucking in the freon. <BR><BR><BR><img src="http://www.dynamicautoworkz.com/cars/BMW%20325i/ac%20recahrge/142-4215_IMG.JPG"><BR><BR><BR><BR> I added about 1 can of freon, but I am very familiar with ac systems, you should do half a can at a time and check your levels. My ac was cold at 25 psi low and 175 high<BR><BR><BR><BR><BR><img src="http://www.dynamicautoworkz.com/cars/BMW%20325i/ac%20recahrge/142-4220_IMG.JPG"><BR><img src="http://www.dynamicautoworkz.com/cars/BMW%20325i/ac%20recahrge/142-4221_IMG.JPG"><BR><BR><BR><BR><BR>at 48 degrees. it was cold enough for me <BR><BR><BR><BR><BR><img src="http://www.dynamicautoworkz.com/cars/BMW%20325i/ac%20recahrge/142-4219_IMG.JPG"><br><BR><BR>if you have to add more than 1 can of freon, you might have a leak and so you will need to check that out. time for a test drive TTYL

[vml]

You mention half can at a time but how do you know when the can is halfway done?

[SecretAznSauce]

you can physically feel it

[tomas3314]

Thanks...its been something I have been meaning to research and address. This makes it a whole lot clearer about what I have to do. Seems easy enough, thanks for the write up. Hopefully it will get attached to the e36 libraryr.

[dmurray14]

Nice...I think I need to do this. With the AC on full blast, I get warm air. How much does the freon cost, as well as the tubing and guage and whatnot? Where would I get this?

Dan

Edit: Oh, one other question - is the car running the whole time?

[thurst0509]

Eric,

You said if you have to add more than 1 can of freon, you might have a leak... Seems to me that if you're having to add freon at all, there's gotta be a leak somewhere right? Since the system cycles the freon, it doesn't seem like it should be "using" any of it up. Or am I missing something here? You probably know more about this stuff than I do.

And thanks for the writeup! Obviously I haven't needed the A/C much lately but last summer it didn't seem to cool as well as it used to. So I was planning to recharge it before the weather heats back up again.

[kinghawk]

Great write up. One question Ive been wanting answered but get lots of different answers is what would I need to do to recharge my A/C after needing to replace my condensor unit.

[SecretAznSauce]

Eric,

You said if you have to add more than 1 can of freon, you might have a leak... Seems to me that if you're having to add freon at all, there's gotta be a leak somewhere right? Since the system cycles the freon, it doesn't seem like it should be "using" any of it up. Or am I missing something here? You probably know more about this stuff than I do.

And thanks for the writeup! Obviously I haven't needed the A/C much lately but last summer it didn't seem to cool as well as it used to. So I was planning to recharge it before the weather heats back up again.

dude, the molecular compound of r134a is much smaller than that of the old r12. everything under high pressure leaks or seeps one way or another. the amount is whats important.

[BMWFAN]

Great write up! Thanks! I can't believe it's already AC time here in Texas...Here we go again..

[SecretAznSauce]

Great write up. One question Ive been wanting answered but get lots of different answers is what would I need to do to recharge my A/C after needing to replace my condensor unit.

after replacing condensor, you should flush your system, add new oil and then pull a vaccum and then replensih the system, our system holds about 2.2 pounds

[SecretAznSauce]

Nice...I think I need to do this. With the AC on full blast, I get warm air. How much does the freon cost, as well as the tubing and guage and whatnot? Where would I get this?

Dan

Edit: Oh, one other question - is the car running the whole time?

yes, the compressor has to running

[Jimmie Jazz]

What year did NA BMWs get switched from R12 to R134a?

[SecretAznSauce]

i believe 93, well i've had two 93's and they both were bmw r134a. I converted a 92 before with no problems

[bmw3er]

they now make the r134 self recharge systems with a gadge built in. it has a green side and a red side of the dial. you just keep the valve open until the needle reaches the green. The hose/gadge kit that is like $25 then you just have to buy the can of r134 each time.

[kinghawk]

Whats the best way for the DIY to pull a vacuum on the system? Also as noted before I would need to upgrade the A/C system to adapt to the 134A gas. What are the appoximate costs for each of the parts so I can get a heads up.

[dmurray14]

This is probably a stupid question, but...

It's fairly cold here right now (45F), but I have tried the AC on warmer days and I'm sure it doesn't blow anywhere near cold. Would I still be able to do the recharge now, while it's still cold, or should I wait until it's warmer out?

[Yonip]

I have a leak in my a/c system. I traced it using a freon with dye. The leak is probably in the evaporator since I see the dye when water starts dripping from evaporator (water condensation). I was able to remove the whole dashboard of my car but I wasn't able to remove the evaporator because I am still trying to figure out how to go about removing the evaporator. I might need to get a bentley manual first before I will start replacing my evaporator. I was driving my bimmer for almost a week without the dashboard then finally installed it back and just fix it later when it is really hot here.

[kinghawk]

after replacing condensor, you should flush your system, add new oil and then pull a vaccum and then replensih the system, our system holds about 2.2 pounds

What does flushing consist of? I heard of just using air but Im doubting what I heard! Also do you add oil before pulling the vaccum or after? And last what steps should I be having the engine and/or A/C running.

[BobCT]

with the gauge and it's worked great. Took about 1/2 a can and made a huge
difference in the output. Change your cabin filter too !

Bob

[SecretAznSauce]

Whats the best way for the DIY to pull a vacuum on the system? Also as noted before I would need to upgrade the A/C system to adapt to the 134A gas. What are the appoximate costs for each of the parts so I can get a heads up.

you can rent a vacuum machine from a rental place. but i bought a vacuum puller from harbor frieght and used it with my air compressor. the forcing air through the pump created a pull, kinda like how turbo works. little 12 dollar gadget but you need a strong air compressor to push it with

[kinghawk]

you can rent a vacuum machine from a rental place. but i bought a vacuum puller from harbor frieght and used it with my air compressor. the forcing air through the pump created a pull, kinda like how turbo works. little 12 dollar gadget but you need a strong air compressor to push it with

Alright thanks. How is a flush done? I guess you can say Im one of the extreme DIYers. I havent taken my car to a machanic for years, fixed every problem Ive had. I saw the vacuum pump from harbor freight also concidering on buying that when I get all the right info about how to fill my system.
Is it possible to do a write up or add to this write up for when the A/C system has been opened for repair?

[Steve530]

This is probably a stupid question, but...

It's fairly cold here right now (45F), but I have tried the AC on warmer days and I'm sure it doesn't blow anywhere near cold. Would I still be able to do the recharge now, while it's still cold, or should I wait until it's warmer out?

You should be able to do this when it's cold. If you have trouble getting the R134a to flow out of the can, you can set the can in a container of warm water.

[jetpilot18]

Great write up! Thanks! I can't believe it's already AC time here in Texas...Here we go again..

Could be worse . . . check out my location

[hellrot325]

Could be worse . . . check out my location

Could be much worse, we are going to have a high of 48 today w/ AM snow flurries It was 80F last week

[jetpilot18]

Could be much worse, we are going to have a high of 48 today w/ AM snow flurries It was 80F last week

I would rather freeze than melt to death with high temps and 100% humidity