The Detailed E30 R-134a Conversion Thread/DIY

[RampageRR]

Anyone have a link/URL for a parallel flow condenser that isn't from Amazon? That link says the part's currently unavailable (with an "unknown" time for restock), so if anyone has a link to another seller of a known good parallel flow condenser, please post it up. Thanks!

[pandaboo911]

The Detailed E30 R-134a Conversion Thread/DIY

Just buy an oring kit for the compressor

I've got something similar going on. Previous owner disconnected the pressure switch and jumpered the plug to power the compressor.



I believe on my 91' 318is I'm working with the original compressor/condenser but converted fittings/o-rings. My question is which pressure switch do I need? OP makes it seem like some special high pressure switch is needed, but wouldn't this only apply for cars with higher pressure compressor?



There is a pretty good price difference between the 2 switches so I'm wondering what the deal with this is.

You only really need the high pressure switch for safety, you can jumper the low pressure switch, but don't run the compressor without refrigerant.

However with the 134a drier the r12 switches won't fit. The newer style is both high and low pressure in one switch and is only needed if you replace the drier. I got one from an e36 at PnP. If you're running the r12 drier, you should at least wire the high pressure switch back. While you're at it just do both, the low pressure switch protects your compressor in case all the 134a leaks out.

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[spike68]

I'm not sure what you're referring to as the top place. Do you mean the manifold?

[jrobie79]

looking for a new compressor (charged my system up and the compressor started smoking)....instead of shelling out the $200+ for the new denso unit - 318is - is anything preventing me from buying this and just slapping my old top plate on?

http://shop.advanceautoparts.com/p/d...7344/3896625-P - reman

http://shop.advanceautoparts.com/p/t...358/10053434-P - new

on rockauto it lists the 4 seasons compressor as a 10pa17c compressor - which the links go to, it appears it just doesnt have the top plate - I have my existing one. Advance has a killer 30% coupon which would bring it down to $134, much more reasonable.

[b-rad]

Great write up.
Have to read all the details.

I have an 325is / S50 swapped with A/C.
I did not do any of the work that is within the hood.
I am not sure what I exactly have for the consider or the compressor.

I would like to replace the fan on the front so that I can slip a oil cooler in there.
Suggestions on fan? or other pics on where to place oil cooler.
I have reg non elec fan still in there and stock ... much like this

Thinking "thinner" fan and then push oil cooler
below as much as I can.

I would like to handle some of the mounting myself and then let my shop do the rest with the Euro filter I bought.

[c0rbin9]

I've got something similar going on. Previous owner disconnected the pressure switch and jumpered the plug to power the compressor.

I believe on my 91' 318is I'm working with the original compressor/condenser but converted fittings/o-rings. My question is which pressure switch do I need? OP makes it seem like some special high pressure switch is needed, but wouldn't this only apply for cars with higher pressure compressor?

There is a pretty good price difference between the 2 switches so I'm wondering what the deal with this is.

[vladimirhtg]

OP, thanks for a great DIY. Especially grateful for the M42 specifics :)

I used PAG oil on all my seals, no ragrets. Even left the lines open from the expansion valve to the engine bay for a week or so and still pulled a great vacuum. We'll see how long that lasts, but it's been good for the last week.

An AC wiring question--(318is, stock compressor, replaced fan, condenser, seals, switch, expansion valve):
Finished the DIY, charged it up with the system all together but the compressor didn't turn on. No voltage at the connector.
Checked for voltage at the high pressure switch--inconsistent (like it cycled every 5-10 seconds, duration ~0.1 seconds).
Checked for voltage out of the evaporator temperature regulator. No dice, nothing. Bought a new regulator, waited on the mail...installed new FAE regulator but still nothing. Jumped the regulator relay, and we got dice!

Of course, then I had voltage at the high pressure switch, but then the high pressure switch was open....before the compressor had even run. Huh. So I jumped the pressure switch leads and went on my road trip with moderately cool AC (didn't dial it in, just 'guessed' at 28oz).

So here are questions:
Why would the evap temp regulator not give me voltage on a system that hadn't even been run yet (obviously a non-frozen evaporator)?
Any ideas on why my brand new high pressure switch would be open on a normal-pressure system? Not really dying to replace it, bought it months ago in prep for the project and don't want to open the system if I can avoid it.

Obviously not excited to run the system without a high pressure switch or evap temp reg but...I'm not too worried about it.

Once I get these issues taken care of, it'll be efficiency time (likely starting with the compressor).

Thanks for helping guys!

[pandaboo911]

I bought an assortment of green orings and that's all I needed.
Also used oring grease to keep the seal/prevent corrosion


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[spike68]

Yeah of wouldn't worry about those. You won't need them for e30s. I believe I had the same ones in my oring kit and I didn't use them

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[Codym42]

1. I didnt have to lube my rings at all. I feel like any kind of lubrication will attract moisture. I have not had any issues with not lubing them.

2. You probably wont use all the rings in the kit. I'm not sure why I had tons of rings left over, but I was happy about it because just in case I did not place an ring correctly and it happened to blow out, Id have an extra laying around. Its pretty obvious which rings go where, but I recommend that while you swap out the rings you compare the sizes of the new ones to the old ones by holding them next to each other. I had a couple of occasions where I thought I had the right size and realized I almost put on a size too big. So be critical about those steps.

3. I recommend using an r-12 flushing agent and some compressed air to run through the lines. I didnt have to do that with mine because my lines were exposed to open air for as long as Ive owned it before my conversion, so all I had to flush was the evaporator, which I just did with some compressed air in one line and holding a towel on the other line. Its effective enough I guess.


As another recommendation. I say just go for getting that new condenser. With r-134a not being as efficient as r-12 the system needs all the help it can get and upgrading to a modern flow condenser along with an aux fan upgrade will help out drastically. Plus those parts are pretty inexpensive. If the compressor winds up not working then you will probably have better luck finding a used one here on the forums for $100.

Awesome thanks!

I've acquired pretty much all the parts for the conversion including a brand new Nissens parallel flow condenser, aftermarket fan, expansion valve, pressure switch, and dryer. I'll probably order some a/c flush as well.

I'll show you what I'm not sure about in the kit. I really doubt these parts are used but I'll post up a pic. The parts circled in red I'm unsure about.

[spike68]

Great writeup! I have a few questions though if someone could help me out.

1. What are you guys lubing your o-rings with? I've heard Nylog or mineral oil works but some say not to use the PAG oil because it attracts moisture.

2. I ordered this conversion kit http://www.autohausaz.com/search/pn....FUI9gQodpGUPYQ

What are the 2 smaller rings and washer looking things for? Its a universal kit so maybe they aren't needed for the e30. I know I need the o rings and conversion fittings.

3. What is the best way to flush out the evaporator and lines? Thought about using brake cleaner or alcohol... not sure if that's a bad idea or not.

Thanks!

1. I didnt have to lube my rings at all. I feel like any kind of lubrication will attract moisture. I have not had any issues with not lubing them.

2. You probably wont use all the rings in the kit. I'm not sure why I had tons of rings left over, but I was happy about it because just in case I did not place an ring correctly and it happened to blow out, Id have an extra laying around. Its pretty obvious which rings go where, but I recommend that while you swap out the rings you compare the sizes of the new ones to the old ones by holding them next to each other. I had a couple of occasions where I thought I had the right size and realized I almost put on a size too big. So be critical about those steps.

3. I recommend using an r-12 flushing agent and some compressed air to run through the lines. I didnt have to do that with mine because my lines were exposed to open air for as long as Ive owned it before my conversion, so all I had to flush was the evaporator, which I just did with some compressed air in one line and holding a towel on the other line. Its effective enough I guess.


As another recommendation. I say just go for getting that new condenser. With r-134a not being as efficient as r-12 the system needs all the help it can get and upgrading to a modern flow condenser along with an aux fan upgrade will help out drastically. Plus those parts are pretty inexpensive. If the compressor winds up not working then you will probably have better luck finding a used one here on the forums for $100.

[Codym42]

Great writeup! I have a few questions though if someone could help me out.

1. What are you guys lubing your o-rings with? I've heard Nylog or mineral oil works but some say not to use the PAG oil because it attracts moisture.

2. I ordered this conversion kit http://www.autohausaz.com/search/pn....FUI9gQodpGUPYQ

What are the 2 smaller rings and washer looking things for? Its a universal kit so maybe they aren't needed for the e30. I know I need the o rings and conversion fittings.

3. What is the best way to flush out the evaporator and lines? Thought about using brake cleaner or alcohol... not sure if that's a bad idea or not.

Thanks!

[LateFan]

For future searchers - these are available aftermarket for a lot less, $50 to $60. "Four Seasons" seems to be one of the major aftermarket AC suppliers.

https://www.amazon.com/Four-Seasons-55593-Hose-Assembly/dp/B001B78YMW/ref=sr_1_1?s=automotive&ie=UTF8&qid=1468866955&vehicle=1986-31-171-------------0&sr=1-1&ymm=1986%3Abmw%3A325e&keywords=1986+BMW+325e+air+conditioning+hose

https://www.amazon.com/Four-Seasons-55914-Hose-Assembly/dp/B000UOABB4/ref=sr_1_2?s=automotive&ie=UTF8&qid=1468867663&vehicle=1986-31-171-------------0&sr=1-2&ymm=1986%3Abmw%3A325e&keywords=1986+BMW+325e+air+conditioning+hose

http://www.partsgeek.com/catalog/1986/bmw/325e/climate_control/a-fs-c_refrigerant_suction_hose.html

https://www.summitracing.com/parts/fss-55914?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-four-seasons&gclid=CMGQ5frb_c0CFQqsaQodWnIJRA

http://www.rockauto.com/en/parts/four+seasons,55914,a/c+refrigerant+hose,6900

[GoldMember]

VERY useful thread - thanks OP!

So my son is having his 86 es converted by a local shop. We're not doing the condenser yet - mostly seeing if the compressor will still work.

They did the dye thing to check for leaks, and they found it at the pipe that wraps around the passenger shock tower and drops to the compressor. It's the very one in GoldMember's post above and I think it might be part # 64538391051. RealOEM doesn't show a shape anything like this one.

It has a joint in it from pipe to soft hose - somewhere just above that joint it's leaking, says the tech. I wasn't there - don't know if it's a cracked pipe, or it's coming up from that joint in the hose.

[ATTACH]109515[/ATTACH]

That pipe seems to list at $180+ most places. $200, 220. Is that right? Seems pretty steep for a pipe / hose. I don't suppose a small city has those shops that fabricate AC hoses - are those still around?

Any ideas or suggestions?

Thanks -

How about a junkyard or used one on eBay? Or if you DO spend the money, have one made that is r134a compatible (barrier hose).

[LateFan]

VERY useful thread - thanks OP!

So my son is having his 86 es converted by a local shop. We're not doing the condenser yet - mostly seeing if the compressor will still work.

They did the dye thing to check for leaks, and they found it at the pipe that wraps around the passenger shock tower and drops to the compressor. It's the very one in GoldMember's post above and I think it might be part # 64538391051. RealOEM doesn't show a shape anything like this one.

It has a joint in it from pipe to soft hose - somewhere just above that joint it's leaking, says the tech. I wasn't there - don't know if it's a cracked pipe, or it's coming up from that joint in the hose.



That pipe seems to list at $180+ most places. $200, 220. Is that right? Seems pretty steep for a pipe / hose. I don't suppose a small city has those shops that fabricate AC hoses - are those still around?

Any ideas or suggestions?

Thanks -