The Detailed E30 R-134a Conversion Thread/DIY

[jeffnhiscars]

Much of the physical restriction when pulling a vac and filling is from the schraeder valve. It can be removed and replaced with a core removal tool. The second most common problem is latent moisture in the system which can actually settle in to the compressor oil and become quite stubborn to remove. The only way to effectively deal with it is to have a micron gauge.

Then there's not purging your hoses properly, inadvertently letting air back in and not having the right amount of oil.

[Garemie]

It took about 8 hours of charging time yesterday to get 24oz of Freon into my system. I need to get at least 4 more in today.

After some fiddling around I discovered that the “can tap” i ordered is probably the problem. The flow restriction it makes is ridiculous. After i tap a can and open the tap valve there is inconsistent flow and I found one position for the valve that allows the Freon to exit, its about 1/2 open. Test your tap and see if its your problem too.

I'm not using a side puncture can tap, I'm using a thread on type. Flows like a mad man. Today I took it all apart again (kill me) and looked for blockages and anything weird. Blew out the evap core a little. I cleaned the screen on the compressor. It's been on vacuum for an hour now. Going to try again. Probably won't get any different results but who knows.

Going by the sight glass, it appears full at like 12oz. Anything more and it looks overfilled.

[325e '87]

I'm struggling with the same exactl problem...it's killing me.

It took about 8 hours of charging time yesterday to get 24oz of Freon into my system. I need to get at least 4 more in today.

After some fiddling around I discovered that the “can tap” i ordered is probably the problem. The flow restriction it makes is ridiculous. After i tap a can and open the tap valve there is inconsistent flow and I found one position for the valve that allows the Freon to exit, its about 1/2 open. Test your tap and see if its your problem too.

[Garemie]

Ok, I replace the condenser and the dryer, resealed and held 30” vacuum for about 12 hours.

I cant get my system to draw in more than about. 10oz. Of refrigerant. I’m getting kind of angry and considering pumping it back down to vacuum and trying again.

My pressures are nearly factory, 40psi low, hovering around 200psi high. I know the pressures need to go up from where they are but Ive been running my engine for an hour now, revving sometimes. When I rev it my low side drops to around 20psi, high side drops a little.

I'm struggling with the same exactl problem...it's killing me.

[S.J.1981]

I can not seem to find R134a cans here in Germany. Either 1kg, 2kg or 12kg tanks which can not be shipped or an extra charge for shipping since they are considered "dangerous goods".

I just received new parallel flow condenser, the correct dryer/receiver, pressure switch and expansion valve, along with various O-rings.

The R134a freon, compressor oil and vacuum pump is all i need. But now i need to ask, if it is alright to use 12a gas (which replaced R134a/R12) or a similar "replacement for R134a". Or do all the hardware myself, top up oil and let a professional vacuum test the system and charge for me.

What do you guys recommend? is that replacement R134a gas alright and go ahead? or let a professional shop do the filling/vacuum part?

[325e '87]

Ok, I replace the condenser and the dryer, resealed and held 30” vacuum for about 12 hours.

I cant get my system to draw in more than about. 10oz. Of refrigerant. I’m getting kind of angry and considering pumping it back down to vacuum and trying again.

My pressures are nearly factory, 40psi low, hovering around 200psi high. I know the pressures need to go up from where they are but Ive been running my engine for an hour now, revving sometimes. When I rev it my low side drops to around 20psi, high side drops a little.

[325e '87]

Thank You!! Ordered.

[The Dark Side of Will]

You'll need a "can tap"

The T-handle drives a spike which punctures the can seal.

https://www.amazon.com/Interdynamics-Certified-R-134a-Dispenser-DV-134/dp/B000CO7Q6U

https://www.autozone.com/test-scan-and-specialty-tools/a-c-manifold-gauge-set-and-components/santech-r134a-can-tap/944974_0

[325e '87]

Ok, i have read everything i can find and am doing the upgrade to the parallel flow condenser this week.

I went and got a vacuum pump and the harbor freight a/c service manifold (red, blue gauges and yellow fill/evac line).

My question is, when I go to refill with 134a do I just screw the yellow hose fitting onto the bottle of 134a? I don’t see if there is a prong in the center that will break that seal. The end of the yellow hose that is supposed to go on the manifold looks like it has some kind of Schroeder valve, or is that the prong that is supposed to break the seal on the refrigerant bottle?

Thanks

[S.J.1981]

id like to ask, before ordering all the parts required. Is there any way i can actually test the compressor? in terms of proper function instead of just if the clutch engages or not?

I know the clutch engages, but the system is empty. Id like to safely test the compressor first. Any suggestions?

Update: Got a 510g can of R12 "replacement" gas, filled the system (i know there is a leak at the condenser and the dryer/receiver is the original 1990 one and rusted out), but i wanted to see if the system can still cool.

So the fan came on, clutch kicked in, and as long as the car was moving, there was 1/2 decent cooling from the vents. So i know the compressor and condenser fan work. I shall be getting a vacuum pump, new parallel flow condenser (Nissens brand), new receiver dryer (R134a) with correct pressure switch, new evap (R134a) and maybe even a new evap (still undecided if i should clean out the original or get a new one).

If someone can be specific with the o-rings linked on page 1, which seal goes where (realoem is not helpful) id appreciate that.

[330SMG]

Looks like this thread is still active so any help is appreciated. I just got to the point of tearing everything apart under my dash and would like to know if anyone thinks my evaporator is good or not. I'm trying am trying to get this done asap. Thank you!

Links to photos since it wont let me upload for some reason...

https://drive.google.com/open?id=1eL1QD7IL4cMVCnQxq_Ti_yrwTX4hyrcm

https://drive.google.com/open?id=1VB...ISmwFe9VUwO9Cg

If it is the original one just change it. Mine blew out late last year. They are not that expensive and you might as well just rebuild the whole system to ensure longevity.

[S.J.1981]

It may look "bad" but honestly only a professional with a leak detector machine can tell.

[jwest11]

Looks like this thread is still active so any help is appreciated. I just got to the point of tearing everything apart under my dash and would like to know if anyone thinks my evaporator is good or not. I'm trying am trying to get this done asap. Thank you!

Links to photos since it wont let me upload for some reason...

https://drive.google.com/open?id=1eL1QD7IL4cMVCnQxq_Ti_yrwTX4hyrcm

https://drive.google.com/open?id=1VBSBIUuEugk1L5opGNISmwFe9VUwO9Cg

[S.J.1981]

Thank you for this detailed write up, despite it being a 2012 thread.

My R12 system is empty, and my local Bosch service center is the only one, who is willing to convert to R134a for me. He gave me a quotation between €2.000 and 2.500, which does NOT include a new compressor or condenser fan (if needed).

Since the system is empty, i was interested to see, from the hardware side, what is required, thankfully you covered all of this.

You gave me the confidence to tackle this myself, then let the professionals correctly charge the system.

[bignslow]

I am in the process of converting mine over. Anyone know what the high side R134a conversion fitting needs to be used? I was under the assumption that all cars were the same but out of the 2 conversion fittings that I got only the low side fits. The high side is different.