The Detailed E30 R-134a Conversion Thread/DIY

[rzmoser]

Thank you, i shall continue searching to find a "shorter" high pressure side adapter then.

Please reply back if you find one. I'm looking for one too

[S.J.1981]

There are different configurations of adaptors so just find one that fits. It can be tight but I've never heard of anyone have to mod that pipe to get one on.

Thank you, i shall continue searching to find a "shorter" high pressure side adapter then.

[jeffnhiscars]

There are different configurations of adaptors so just find one that fits. It can be tight but I've never heard of anyone have to mod that pipe to get one on.

[S.J.1981]

What did you guys do regarding the high pressure side valve?

Managed to remove the schrader valve from the low pressure side, and screw in the R134a adaptor, hood closes without issues.

The high pressure side adaptor sticks out about 1" or so, before the hood support hinge hits it. Can that whole hose be "twisted" somehow (when removing for replacing the o-rings), or keep the R12 factory fitting and screw in the R134a when filling only?

BMW does not make that hose anymore, it is from the evap to receiver/dryer line.

[jeffnhiscars]

I think ultimately I didn't properly flush the system. It's a heat wave in my area, I think I'm going to hand this over to a shop to have it flushed and refilled. I'm going to save myself from heat stroke while working on it.


It's gotta just be too much oil. Probably mineral oil too.

Mineral oil has to be thoroughly flushed before converting as it does not get along with r134 at all. I'm not exactly sure what the results are but I do know they are bad.

[Garemie]

I think ultimately I didn't properly flush the system. It's a heat wave in my area, I think I'm going to hand this over to a shop to have it flushed and refilled. I'm going to save myself from heat stroke while working on it.


It's gotta just be too much oil. Probably mineral oil too.

[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