E30 A/C Service Valves

[gilber33]

I am working on putting the AC all back together in my 89 E30. Someone had completely removed it some point in its life. One thing I could not find information on was the service valves. I see these Replaceable service valves that seem to go on the suction lines but it doesn’t look like the suction lines in my car would accept these. The replaceable ones: And the ports on my lines. I just want to make sure that the ports on my lines look correct and I’m not missing anything. I don’t know if there are several variations and the service valves on my lines are fixed?

[ForcedFirebird]

E30's are equipped with r12 fittings. When r134 was mandated, so were a whole new fitting system. When you see r134 ports in an e30, it's usually because someone bought a "r134 conversion kit" which is just the two adapters and r134 gas. If you are converting, you will need the adapters - and really should update the system since r134 in a r12 system, they never get as cold. There's a great thread on here for truly converting to r134...

https://www.r3vlimited.com/board/forum/e30-technical-forums/e30-faq-and-diy/213651-the-detailed-e30-r-134a-conversion-thread-diy

[gilber33]

E30's are equipped with r12 fittings. When r134 was mandated, so were a whole new fitting system. When you see r134 ports in an e30, it's usually because someone bought a "r134 conversion kit" which is just the two adapters and r134 gas. If you are converting, you will need the adapters - and really should update the system since r134 in a r12 system, they never get as cold. There's a great thread on here for truly converting to r134... https://www.r3vlimited.com/board/for...ion-thread-diy

I am very familiar with that thread and have read it a few times. The whole system has been updated to R134. I put in a new evaporator, condenser, expansion valve, drier, etc. That post doesn’t mention anything about the lines and adapters for r134 valves. So are these valves for r12? How are they converted for r134?

I did some more digging and I found these on ECS:



Do I remove the schrader valve from the R12 port and then screw this one on? And this adapter valve is hollow, so does a schrader valve get screwed into this or does a R134 valve get installed onto this? Thanks

[roguetoaster]

Doesn't look like that retrofit cap, which appears to be for 134a, has a provision for a schrader, perhaps it threads down low enough to use the current valve. If so, this may be to accommodate some systems that have a non-schrader type valve.

Also, the small new port goes on the larger diameter line, and I have heard tell of a 60% R-12 to R-134a weight of charge equivalency, but cannot confirm.

You may well be better off buying a generic kit that has more components for a lower cost, as $15 per adapter seems high.

[gilber33]

Doesn't look like that retrofit cap, which appears to be for 134a, has a provision for a schrader, perhaps it threads down low enough to use the current valve. If so, this may be to accommodate some systems that have a non-schrader type valve.

Also, the small new port goes on the larger diameter line, and I have heard tell of a 60% R-12 to R-134a weight of charge equivalency, but cannot confirm.

You may well be better off buying a generic kit that has more components for a lower cost, as $15 per adapter seems high.

This one appears to thread on to the R12 valves and then I assume a schrader valve threads into this. I’ll look at generic kits. I didn’t know that this was a thing with different valves for the two refrigerants.

[roguetoaster]

Normally you'll see small bore threads for a schrader install point, but I didn't see anything that looked like that on the valve in question, but they could be there.

[gilber33]

I think that adapter has threads for a schrader valve, it’s just hard to see. Anyways, now that I know what I need to do there, an issue with the compressor and suction line came up tonight. I had to piece this while AC system together and the suction line does not fit the inlet on the compressor. So looking at compressors on eBay I see there are a couple types - one with the valve and one without. So I’m assuming the compressor that doesn’t have the valve is smaller? Now I need to figure out is the compressor wrong to the car or is the hose? If so, which one do I need to replace? Sent from my iPhone using Tapatalk

[roguetoaster]

Try to reference the P/N of the compressor and see which hose matches/if that hose has thread pitch or other info listed that would let you compare it to your current.

Ultimately, you should probably just change the hose, considering the age of the current part, and with the presumption that your compressor is already known to work.

[gilber33]

From what I can gather the hose is supposed to be paired with a Seiko compressor. And I picked up a Bosch/Behr compressor. Trying to find the other hose. Sent from my iPhone using Tapatalk

[tomstin]

Trying to find the other hose.

If you have a hydraulic hose shop nearby they can often help with fittings and hoses. I took my R12 hoses to them and they replaced the hose with barrier hoses compatible with R134A.

[gilber33]

If you have a hydraulic hose shop nearby they can often help with fittings and hoses. I took my R12 hoses to them and they replaced the hose with barrier hoses compatible with R134A.

I do have some around me, but I’d be afraid of them making a hose without have one for them to copy. Not only is the nut a little too small on the one I have, but the angle of the hardline at the end doesn’t line up perfectly.

I read that the Seiko and BOSCH compressors are interchangeable, if that’s the case, then I just have no idea what hose mine came off of so I know nothing else is screwed up.

While looking for info I also found people saying the Bosch compressors are not r134 compatible. Is this the case? I will have the system evacuated and charged by a shop, but will there be a problem with the compressor I have?

[ForcedFirebird]

The r134 adapters are available everywhere, they are not BMW specific. Your local auto parts store will have both fittings for about $10.

As far as the compressors, yes there were a few different types in e30's over the years - with different hoses to match, they are NOT directly interchangeable. There's also Denso, along with Bosch and Seiko - and they all have different fitting arrangements.

As far as getting a custom hose to fit, just order the ferrules/fittings/hose, then cut to your dimensions, and bring the assembly to a hydraulic hose shop and have them crimp only.

I have a few compressors sitting on the shelf here at the shop, and it appears the hoses you have are for a Denso. The large nipple on it is right next to the little one, and smaller diameter than the Bosch and Seiko.

[gilber33]

The r134 adapters are available everywhere, they are not BMW specific. Your local auto parts store will have both fittings for about $10.

As far as the compressors, yes there were a few different types in e30's over the years - with different hoses to match, they are NOT directly interchangeable. There's also Denso, along with Bosch and Seiko - and they all have different fitting arrangements.

As far as getting a custom hose to fit, just order the ferrules/fittings/hose, then cut to your dimensions, and bring the assembly to a hydraulic hose shop and have them crimp only.

I have a few compressors sitting on the shelf here at the shop, and it appears the hoses you have are for a Denso. The large nipple on it is right next to the little one, and smaller diameter than the Bosch and Seiko.

Thanks for the info. I'll grab the adapters locally.

The compressors are a little frustrating. I can't seem to find any rhyme or logic for which one would be on the car and there seems to be several variations, so part numbers are everywhere. The compressor I have on the car is from an 89 325ix, the other compressor I have is from a late 325e (both of these are the same Bosch compressor), and the hose I have is from an 89 325i, but yet they don't match up despite being from the same year.

Do I need to be worried about the Bosch compressor and converting to R134a if I am taking it to a shop to have it completely evacuated and recharged with the correct pag oil and everything?

[ForcedFirebird]

Welcome to the club. I have been professionally working on e30's for over 10yr and have had two cars in the shop side by side, same year different compressors - and wondered the reasoning too.

As far as r134 compatibility, not sure. I do know r134 uses different oil than r12, but not sure why the compressor wouldn't work (maybe seals?).

EDIT: Found this on an e32 forum:

that are only a very few compressors and only used in the very early stage in some models.
Excerpt from Johan's site: Converting the aircon system to R134a on most E32 is quite simple. All you have to do is replace the dryer and the old mineral oil used with R12 for PAG oil. BMW has a kit available for this purpose. However some early cars have a compressor made by Kiki-Diesel Zexler for Bosch for Behr for BMW (not so simple anymore huh?). The seals on these compressors contain elastomers that can't keep the R134a molecules in. The retrofit manual lists the following part numbers for unusable compressors:


Compressors incompatible with R134a (part numbers)
1 377 940 1 377 941 1 377 943
1 377 944 1 377 946 1 377 947
1 385 416 1 385 930 1 386 411

[gilber33]

Welcome to the club. I have been professionally working on e30's for over 10yr and have had two cars in the shop side by side, same year different compressors - and wondered the reasoning too.

As far as r134 compatibility, not sure. I do know r134 uses different oil than r12, but not sure why the compressor wouldn't work (maybe seals?).

Then I'm glad I'm not the only one experiencing this.

Apparently some compressors aren't compatible with R134, but none of the conversion/update threads mention that. I think it's more of a matter of making sure that the system has been flushed clean from the R12 stuff. It appears that the compressor I am using was already part of an R134a update since I dumped out PAG oil with UV dye in it when I got it.