Recharging A/C

Post Sun Jun 23, 2013 10:26 am

I've been told you need some kind of adaptors to re-charge the A/C on an E30.

As far as I understand, the high/low connectors on our cars are known as R134a, but the modern A/C machines use R12?

So do I need R134a to R12 adaptors?

Any links to eBay items would be useful

Post Sun Jun 23, 2013 10:31 am

Wrong way round. R12 and R134a are the refrigerant oils - Modern machines use R134a; R12 has been banned in the EU, so a top-up requires a sneaky trip to Ukraine.

The R12 to R134a conversion kit includes new valves (the adaptors) and a new receiver/drier, but on a 20+ year old kit you might end up replacing most of the system. The O-rings for R12 aren't that great at stopping R134a, so you get leaks in places you never had leaks before.

Obligatory Wiki link:

http://www.e30zone.net/e30zonewiki/inde ... efrigerant

Post Sun Jun 23, 2013 10:53 am

I work in a garage and we got an A/C charging machine, so was planning to do it that way.

Grrrmachine, thanks for that. Sounds like quite a PITA...Checked the kit price with BMW and it's 145 quid.

Considering I don't even need an A/C, I don't want to spend over 100 quid on something that I'll rarely use.

To be honest, the reason I thought about recharging/oiling it up, is because the compressor itself seems to be making a "checking noise", if that makes sense? The AC is always off, but the noise is there when the engine is running - maybe bearings?

The belt is new, so I guessed if I get everything recharged that might cure the noise...Otherwise, windows-down is my AC

Post Sun Jun 23, 2013 10:59 am

IF you can find the recharge valves elsewhere, then you can get the condensor for a lot cheaper - I paid about 30 quid for a brand new one, but my system is R134a from factory.

Post Sun Jun 23, 2013 11:26 am

The receiver dryer in the R134a kit has the same part number as what I found on BMWfans.info

So what would be the point of replacing it?

Would it possible just to get the valves and recharge the system as it is? I'm not too worried about it being freezing-cold. I only want to get rid of the annoying noise from the compressor...

Post Sun Jun 23, 2013 11:55 am

Are you absolutely sure the kit you have now is R12?

If so, you need to replace the drier with an R134a-specific unit to recharge the system. This is 114 quid from BMW (80% of the kit) or 32quid from Amazon (click here). They are made by Hella, Valeo, Nissens or NRF. The valves themselves are only 6 quid each from BMW.

If your kit is already R134a, you ought to change the drier anyway as that's considered a service component.

If you just want the noise gone, cut the A/C belt.

Post Sun Jun 23, 2013 12:34 pm

Sounds silly, but how do I check which kit I have? Based on the valves? I assumed since the car's 1990, it will have R12?

Yeah, cutting/removing the belt is probably the best option lol

My condenser is a big piece of chocolate, so will need to be replaced + dryer + valves and we're talking close to £100...

Doesn't sound too bad, but I've got more important things to worry about

Post Sun Jun 23, 2013 12:57 pm

The quickest way to check would be to get the part number off either the compressor or the receiver/drier. The r/d is really under the car behind the driver's headlight, so just park on a kerb and stick your head underneath.

Bear in mind I'm no aircon expert; I've not installed my own system yet, I just wrote the Wiki retrofit article from the Tech Help archives