Anybody ever change the A/C expansion valve in their E30 here?

[Galicianslash]

Hello fellow bimmerheads, I wanted to know how to change the A/C expansion valve that's by the evaporator for the A/C, Im pretty sure that's the reason my A/C is not working, anybody ever do it? Do you have to take out the dashboard? Can anybody help?

[djb2]

E30 A/C evaporator removal and expansion valve renewal instructions
by Donald Becker

Why you might need to do this:
Leak in A/C system
Flushing A/C system
Poor A/C performance after verifying full charge
Poor A/C performance only at idle
Conversion to r134a

Before starting this job

Remove any remaining refrigerant from the system
R12 must be recovered, typically free if you have enough
(The shop will resell it at $3/ounce = $100 for a full charge)

Get the following materials:
New insulating foam, 1/2" thick, 2"x3" sheet or 12"x 1/2"
My existing foam turned into sticky black bits when touched
New o-rings, HNBR, Nitrile (N-Butyl) or Neoprene
BMW lists o-rings by I.D. mm, vs standard sizes or dimension
1 7.64mm #6
2 11.1 mm #8 x 1/16" I.D.: 11.1mm O.D: 14.3mm T: 1.6mm
2 14 mm #10 x 1/16"
If you are replacing all o-rings buy
64-50-1-468-463 7.65mm (#6, for 3/8" tube) o-ring $0.18, 5@
64-50-1-468-464 11.1mm (#8, 1/2") o-ring $0.13 5@
64-50-1-468-465 14mm (#10 5/8") o-ring $0.17 4@
64-50-1-468-466 17mm (#12 3/4") o-ring $0.23 3@
Buy at least one spare of each size. Your compressor vapor inlet
may take #10 or #12

- Yes, five at the expansion valve. The parts sheet doesn't show
the o-ring in the valve,
which is likely the one that is leaking.
- I paid $1.86 each for the 11.1mm, the only two o-rings that the
Annapolis BMW dealer had in stock. It was July: what do they put on
cars in for service? They were silver in color. HNBR is usually dyed
green, and neoprene is blue. The silver ones are usually the special
ones for the oil cooler.
BMW of Arlington had green o-rings in stock, $1.08, 1.32 and 1.96.
AutoHausAZ had the same o-rings for $0.18 to $0.23 each. At that price
it's an easy decision to get every o-ring needed for the system and
spares.
- You'll read that you must use only green HNBR o-rings in A/C systems.
HNBR is Hydrogenated N-Butyl Rubber, which is just Nitrile
(aka N-Buta) rubber with an chemical add-on that keeps it from
absorbing chemicals, such as r134a oil, at high temps. Standard
black o-rings are usually Nitrile or Neoprene, and will work fine at
the moderate temps in the expansion valve. But Viton, also black,
will break down with r134a. So use green or blue o-rings if you can.

You will need the following tools
A Crescent-style adjustable wrench, metric ;-)
17mm, 19mm, 22mm and 24mm box wrenches (or a second Crescent wrench)
The usual 10mm, 13mm and 17mm sockets and #2 screwdriver
Drill and small diameter bit
A vacuum cleaner

Remove the passenger seat
- Yes, really. Four 17mm head bolts/nuts in three minutes will
save lots of awkward, frustrating twisting later. Add five
minutes to vacuum out the cheerios and rinse off the sticky coins.
Remove the glove box and center console
- You only need to loosen, not remove, the three 10mm cap screws
forward of the glove box.
- There is an oft-forgotten 8mm cap screw pointing up just above
the console cubby hole. It's easily located by feel.
Remove the passenger side trim pieces above and around the glove box
- Obvious #2 screws, plastic twist screws and a little wiggling
Locate the expansion valve
- Follow the two A/C hoses forward of the glove box
Verify that the system is depressurized

At this point you'll see that you need to detach the hoses to remove the
cover over the expansion valve and evaporator.
Remove the small A/C hose
- Holding the valve body with the Crescent wrench, use 17mm box wrench
- It will drip oil, be ready to seal or plug with tape, paper
towel, or small plastic bag and rubber band.
You now have room to remove the large A/C hose
- 24mm box wrench, hold valve body with Crescent wrench
Remove the cover
- Four screws hold it on, only three are visible
- Cars through at least 1987 have #2 Phillips heads, late cars T15 or T20
- Wiggle, twisting and minor force needed to free the cover
- Don't lose the rubber "spaghetti" seal in the groove
If you only need to replace o-rings or service the expansion valve, you
may remove it now.
Loosen the two tube connections to the evaporator
- 19mm and 22mm, again holding valve body with wrench

If you are removing the evaporator, just leave the expansion valve on
for now and put masking tape over the open holes. The evaporator just
pulls out from air box, tilting to the rear to clear the body and engine
wiring harness. You may find it easier to unplug the harness from the
computer and clip some wire ties to move it out of the way. At first
you'll be convinced that your car is different, but it really is
possible to gently wiggle it out without bending the evaporator fins.

________________
Cleaning and Renewing the Expansion Valve
Note: A new r134a valve is about $20. It's easier to just buy new.

Don't bother with anything more than a quick wipe-down now.
The expansion valve is very robust, except for that copper tube on the
end. That sealed tube contains liquid R12.
The opposite end has what appears to be a brass plug with a single
small hole at the edge. This is actually the "superheat" adjustment,
threaded and sealed with an o-ring.
Mark the position of the hole. Don't just scratch the end, mark the
side and memorize the position. You'll likely put additional scratches
on the end while removing the plug. You might use a feeler or depth
micrometer to measure how far the plug is screwed in.
Drill a second hole opposite the first, about the same size and depth.
I used a Dremel.
Use the two holes to unscrew the plug. A pin spanner is the correct
tool, but no one has one of those. Figure out how to do it with a
needle-nose pliers, circlip pliers, or two drill bits and a
Crescent wrench.
Inside there is only an o-ring, spring and plug.
Clean everything now.
If the spring is broken or rusted, buy a new expansion valve.
If the valve plug is deeply grooved, buy a new part.
If the pin that holds the valve open is loose, buy a new part.
Clean and inspect the o-ring contact points. I used a Dremel
wire brush.
Install a new o-ring and reassemble
________________

"Reinstallation is the reverse." Of course it never quite is, but...

[Galicianslash]

thanx a lot djb2!!

[zydio]

that is awesome. i need to do this to mine before summer gets here. thanks for a great guide.

[turbochargedv8]

hey djb2
im replacing my expanion valve and dryer to hopefuly get the ac going ok so theres 5 o rings on the expansion valve
i know theres others where the ac lines connect how about the compressor itself??

[kellie]

hey djb2
im replacing my expanion valve and dryer to hopefuly get the ac going ok so theres 5 o rings on the expansion valve
i know theres others where the ac lines connect how about the compressor itself??

Go to realoem.com and look it up in the exploded diagram. It doesn't appear that there are any, it just looks like the lines attach with flare nut fittings kind of like a brake line.

[Jak]

Well realoem may not show them but they are there. I just pulled my lines from my compressor so that I can put a sanden upgrade in there. Where there is a fitting there is an o-ring. They are usually on the line side and not the fitting side.

Kellie, I thought techs should know this?

[moberg12]

I doubt she works on E30 A/C systems to often

[kellie]

Well realoem may not show them but they are there. I just pulled my lines from my compressor so that I can put a sanden upgrade in there. Where there is a fitting there is an o-ring. They are usually on the line side and not the fitting side.

Kellie, I thought techs should know this?

I've never replaced an E30 compressor. How many E30 owners do you know who take their car to the dealership for service? My A/C works, so I've got no reason to take mine apart.

Perhaps the o-rings aren't available separately. Here ya go: http://www.sjdiscounttools.com/fjc4275.html

Edit: Thanks, moberg.

[djb2]

BMW doesn't have diagrams for the compressor internals. The internal seals needed depend on the compressor and are not simple o-rings. You'll probably need to buy them from an A/C specialty place.

The connections to the compressor do use standard o-rings. The are "tube o-ring" connections, just like the rest of the system.

The hose and tube o-rings are all standard SAE sizes. There is no reason to get them at the dealer -- they are expensive there, and none of the local dealers had all of the sizes in stock (!). They should be $0.08-$0.25 from a reasonable supplier.

O-ring info
The A/C system is built with SAE sized hoses and connections.
BMW lists o-rings by I.D. in mm, vs standard sizes or dimension
Thus a #6 o-ring, which is 3/8" or 9.525mm, is listed by BMW as 7.64mm

Expansion valve and evaporator, 17/19/22/24mm wrenches
One 7.64mm #6
Two 11.1 mm #8 x 1/16" I.D.: 11.1mm O.D: 14.3mm T: 1.6mm
Two 14 mm #10 x 1/16"
(Fifth o-ring is for the superheat adjustment plug)
ETK lists 11.1 and 14mm (602/603) for evap side of exp valve
Compressor
64-50-1-468-464 11.1mm for outlet (see high pressure hose)
Either
64-50-1-468-466, 17mm (19x17mm) (3/4", #12) for Bosch inlet
or
64-50-1-468-465, 14mm (#10) for Denso inlet
Condenser
64-50-1-468-464 11.1mm for inlet (high pressure hose)
64-50-1-468-463 7.64 for outlet (hose to drier), 17/19mm wrenches
Drier
64 50 8 390 601 Two 3/8" (#6) o-ring for tube fittings
64 50 8 390 602 One 1/2" (#8) o-ring for pressure switch
Note: For two pressure switch drier only. Switch with wire leads
is pipe threads, pronged switch is o-ring sealed. New style drier
uses a combined pressure switch with a Schrader valve connection.
Firewall
Liquid connection 17/19mm wrenches
64-50-1-468-463, 7.64mm (3/8", #6)
Vapor 24/27mm wrenches
64-50-1-468-465, 14mm (#10)

O-ring count: 5X #6, 5X #8, 3X #10, 1X #12
64-50-1-468-463, 7.64mm (3/8", #6) new part number for '601
2@ drier, 1@ tube connection, 1@ E.V., 1@ condenser outlet
64-50-1-468-464, 11.1mm (1/2", #8) new part number for '602
1@ drier switch, 2@ E.V., 1@ compressor, 1@ condenser inlet
64-50-1-468-465, 14mm (#10)
2@ E.V., 1@ tube connection, 1@ compressor suction (late compressor)
64-50-1-468-466, 17mm (#12)
1@ E.V., 1@ compressor suction (early compressor), 1@ Bosch manifold

[kellie]

.....

I like this guy! ^

[Jak]

I've never replaced an E30 compressor. How many E30 owners do you know who take their car to the dealership for service? My A/C works, so I've got no reason to take mine apart.

Perhaps the o-rings aren't available separately. Here ya go: http://www.sjdiscounttools.com/fjc4275.html

Edit: Thanks, moberg.

Sorry, I wasn't saying that the A/C system is E30 specific. Just that I thought techs had a general knowledge of automotive systems. And the fact that A/C lines have o-rings would be included in that statement. Besides, I was only teasing.

I think that Djb2's statement falls more in line with what I meant.

The hose and tube o-rings are all standard SAE sizes.... The A/C system is built with SAE sized hoses and connections.

As for the OP's question, If you open the system to change any part of it you should change the receiver/drier too.

[kellie]

As for the OP's question, If you open the system to change any part of it you should change the receiver/drier too.

Agreed. And don't buy it from the dealer. I bought one from an OEM parts supplier for $17, and it was EXACTLY the same as the original one that I removed from the car. Same manufacturer and everything. I think the dealer charges $50 something, and that's with my employee discount.

[E30Nova]

Since there's a ton of info in this thread, is this all that's needed to convert to R-134A? The O-rings, I mean. Yeah I know everyone says R-134A doesn't blow as cold as newer cars but I want to be able to fill up the A/C for less than couple bills every couple years.

Matt

[djb2]

No, it's not all that's needed.

The big challenge with the e30 is the compressor seals. Some compressor types have Viton internal seals. These break down with r134a and must be replaced, either by opening the compressor or buying a different one.

The old o-rings have less of a compatibility issue, but they are so easy and inexpensive to update with HNBR o-rings that you might as well do them all at once. Why are they pushed so often as "important"? Exactly because they are cheap -- they can be sold at a high mark-up.

The old drier might not be compatible, but since it should be replaced that's not an issue.

Replacing the expansion valve will improve performance. It's also a common leak point on BMWs, including later models. The hidden o-ring around the superheat adjustment can leak all of the refrigerant and then re-seal so that the leak can't be found with a sniffer.

[kellie]

I "retrofitted" my car. There's a bulletin that BMW put out many, many years ago stating that the compressor in my car isn't R134a compatible and would need to be changed in order to retrofit. I decided to give it a shot anyway, just to see what happens. I've got a spare compressor, and nothing to lose, so why not?

I evacuated the system in my car (not that it mattered, because I later found a gigantic leak), replaced a torn hose and my receiver dryer, switched the valves, and filled it back up with R134a and a little oil. That was 6 months ago and my AC still works like a charm. It doesn't blow as cold as my Subaru, but I think that's just the nature of the beast.

I know I didn't do it the "right" way, and who knows how long it will work, but so far, so good.

djb, I was under the impression that it was the oil that broke down old o-rings and seals, and that's why it's recommended that Ester oil is used in a retrofit...what say you?

[84318i]

First, thank you for all the info in this thread on the different o-rings!

Second, I heard from the dealer they do not sell any R12 hardware anymore, and everything is only r134a. Is this true ?

Basically, if one is putting an a/c system into a car that doesn't have one currently (it was completely removed by me last year). What would be the optimal way to do this ? Buy all new r134a components ? Is the condenser/evaporator the same between the r12 and r134a units ?

Thanks!

[djb2]

djb, I was under the impression that it was the oil that broke down old o-rings and seals, and that's why it's recommended that Ester oil is used in a retrofit...what say you?

For some of the materials it's the lubrication used with r134a that's the problem. R12 uses mineral oil, which provides excellent lubrication, only breaks down at high temperatures, is stable in the presence of moisture and is compatible with many materials. R134a lubricants.. none of those.

For the compressors the problem isn't just the lubricant, it is that Viton doesn't work with R134a. So using a different lubricant doesn't avoid the problem.

[Jak]

I am doing a complete conversion to R134a now. Everything except the evap core and a couple lines are being replaced. I am using a Sanden 508 compressor with a customer adapter plate. I have a new r134a expansion valve. I am replacing the condenser and aux fan with one from a late E36. I am not sure if I am going to use the E36 drier yet as I may use a generic one with standard fittings. I am using the pressure switch from an E36 and will be making custom lines to connect it all together.

All of this will essentially make it a true R134 system and it should work as well as any new car. I will post a write up of this when it is complete. As of right now, I am about 40% done and with my schedule I imagine it will be another month before its done. Just in time for summer.

[84318i]

I am doing a complete conversion to R134a now. Everything except the evap core and a couple lines are being replaced. I am using a Sanden 508 compressor with a customer adapter plate. I have a new r134a expansion valve. I am replacing the condenser and aux fan with one from a late E36. I am not sure if I am going to use the E36 drier yet as I may use a generic one with standard fittings. I am using the pressure switch from an E36 and will be making custom lines to connect it all together.

All of this will essentially make it a true R134 system and it should work as well as any new car. I will post a write up of this when it is complete. As of right now, I am about 40% done and with my schedule I imagine it will be another month before its done. Just in time for summer.

Is it a required to replace the condenser and evaporator and lines, they could not be re-used from the r12 system ?

Thanks and looking forward to a write-up!

[Jak]

It is my understanding that for a complete retro fit that the Evap core is sufficient but the condenser is not. You need one with a greater BTU rating.

As for the lines, I have to replace most of them because the fittings are different on the E36 and on the Sanden compressor. Besides, they are almost 20 years old and mine look like they are getting brittle. The only ones I will be keeping are the metal ones.

I'll try to give more detail when I get the writeup done. I am at work right now so sorry if i'm being a little vague.

[turbochargedv8]

where can i order some of that foam that goes on the expansion valve

[conecaster]

BMW doesn't have diagrams for the compressor internals. The internal seals needed depend on the compressor and are not simple o-rings. You'll probably need to buy them from an A/C specialty place.

The connections to the compressor do use standard o-rings. The are "tube o-ring" connections, just like the rest of the system.

The hose and tube o-rings are all standard SAE sizes. There is no reason to get them at the dealer -- they are expensive there, and none of the local dealers had all of the sizes in stock (!). They should be $0.08-$0.25 from a reasonable supplier.

O-ring info
The A/C system is built with SAE sized hoses and connections.
BMW lists o-rings by I.D. in mm, vs standard sizes or dimension
Thus a #6 o-ring, which is 3/8" or 9.525mm, is listed by BMW as 7.64mm

Expansion valve and evaporator, 17/19/22/24mm wrenches
One 7.64mm #6
Two 11.1 mm #8 x 1/16" I.D.: 11.1mm O.D: 14.3mm T: 1.6mm
Two 14 mm #10 x 1/16"
(Fifth o-ring is for the superheat adjustment plug)
ETK lists 11.1 and 14mm (602/603) for evap side of exp valve
Compressor
64-50-1-468-464 11.1mm for outlet (see high pressure hose)
Either
64-50-1-468-466, 17mm (19x17mm) (3/4", #12) for Bosch inlet
or
64-50-1-468-465, 14mm (#10) for Denso inlet
Condenser
64-50-1-468-464 11.1mm for inlet (high pressure hose)
64-50-1-468-463 7.64 for outlet (hose to drier), 17/19mm wrenches
Drier
64 50 8 390 601 Two 3/8" (#6) o-ring for tube fittings
64 50 8 390 602 One 1/2" (#8) o-ring for pressure switch
Note: For two pressure switch drier only. Switch with wire leads
is pipe threads, pronged switch is o-ring sealed. New style drier
uses a combined pressure switch with a Schrader valve connection.
Firewall
Liquid connection 17/19mm wrenches
64-50-1-468-463, 7.64mm (3/8", #6)
Vapor 24/27mm wrenches
64-50-1-468-465, 14mm (#10)

O-ring count: 5X #6, 5X #8, 3X #10, 1X #12
64-50-1-468-463, 7.64mm (3/8", #6) new part number for '601
2@ drier, 1@ tube connection, 1@ E.V., 1@ condenser outlet
64-50-1-468-464, 11.1mm (1/2", #8) new part number for '602
1@ drier switch, 2@ E.V., 1@ compressor, 1@ condenser inlet
64-50-1-468-465, 14mm (#10)
2@ E.V., 1@ tube connection, 1@ compressor suction (late compressor)
64-50-1-468-466, 17mm (#12)
1@ E.V., 1@ compressor suction (early compressor), 1@ Bosch manifold

Well done, might I add a thing or two.

In removing the Evaporator or accessing the cover plate over the TXV, I was able to simply remove the two plastic nuts, one under the shifter boot and one under the rear ash tray between the seats. Then after disconnecting the plastic twist lock up near the firewall I was able to shift the side panel down a rear, far enough to access the unit. I also removed the Plastic air ducts next to the TXV housing for easier access. It connects the climate box to the rear floor vents under the carpeting, It snaps on and has one screw hold it no big deal.

Also, The four screws holding the cover plate are easy to remove except for one back up behind the TXV in a narrow spot nearly impossible to get to. I had to cut down the handle on a screw driver and slowly and obnoxiously work it out in small does. I did not reinstall it. Forget it you don't need it. I simply used some black plastic sealer for windshields you can get at auto zone. Its a mallable semi solid material sold in lengths, wrapped into a coi in a square box, that can be shaped into the channel before reinstalling and will stick there just fine thank you BMW.

One critical issue that was left out was the Thermo tube which inserts from the driver side of the counsel. As you pull the Evap. out you will also detach the thermo tube and you won't even know it. It tooik me alot of head sctratching to understand the issue because its easy to just think the H-block TXV works on its own without a thermostat, but the thermo tube must be reinstalled when reinstalling the Evap.

The Thermostat tube is long enough that you can pull it all the way across to the passenger side. There is a punched hole in the fins you must insert it in before sliding the Evap. , along with the peel and stick foam rubber space filler, back into the Climate control housing you pulled it out of.

[conecaster]

I am doing a complete conversion to R134a now. Everything except the evap core and a couple lines are being replaced. I am using a Sanden 508 compressor with a customer adapter plate. I have a new r134a expansion valve. I am replacing the condenser and aux fan with one from a late E36. I am not sure if I am going to use the E36 drier yet as I may use a generic one with standard fittings. I am using the pressure switch from an E36 and will be making custom lines to connect it all together.

All of this will essentially make it a true R134 system and it should work as well as any new car. I will post a write up of this when it is complete. As of right now, I am about 40% done and with my schedule I imagine it will be another month before its done. Just in time for summer.

Having messed with converting my E30 to other gases I think you are right on with installing a larger Condensor. I converted mine over to R406a, I installed barrier hoses under the hood but the hoses inside going to the TXV where not available that I could find. The car did not cool much at all. I bought a new compressor. It still did not cool and the rebuilt compressor leaked. They wouldn't replace it. I went to the junk yard, Pull a Part, and found a Sanden 508 with a mounting bracket, such luck, not easy or cheap to find/buy. I had hoses made to fit it and installed it with the 406.

The hose fittings did not match right and I had slow leaks that took me a long time to find. In my attepts to get it to cool I discovered that the super heat adjuster can be tightened to better cool HCFCs. I have not used 134 but I believe it would be the same for it as it was for 406. It cooled fine on 406. 406 has about half r22 in it and r22 is cold. But my continued leaks drove me to tearing it down in search of the leaks which now showed oil on the unneccesary hose fittings on earlier model E30's. Later versions don't even have these joints. The main offender was the joint next to the R/Dier which runs from the Comp. to the Cond.

I acquired r12 and readjusted the TXV. What a difference, R12 releases heat better than all of the others, the vent temps drop so much lower. My nagging hose leaks still nagged me and I noticed oil again on the conversion fittings, This time I just gave up and bought a can of Super seal, made by Cliplight. That stopped the leaks But I was out of R12 so instead of spending the money I tried es12a, I had to tighten the TXV adjuster 2 turns to get the Es12 to cool. Its different!!

I got it to work, but I learned a great trick from an online pro to get it to load right. You must use a hose on the condensor to get it way low in pressure. He taught mne that this technique will get better cooling from 134 as well, I loaded many cans of the stuff before I could feel the liquid return on the suction line. When I was done I had 30 lbs low and 200 lbs high side pressure. I don't understand why it worked like this but it cooled great. Only issue is idle cooling which suffers with es12 due to the smaller condensor. I would use es12 before doing a 134 conversion because you need not replace oil or hoses to use it, It cools well enough I doubt most would care< i had low 40's vent temps, just tighten the txv adjuster two turns and hose down the condenser to get enough mass in there to get the pressure high on the high side, it really does work well this way.

I found a 30 lb cylinder of r12 shortly there after on Craig's list for $200. I went back to R12 in the end. So I loaded the R12 and got it running great, I turned off the engine and hear a hissing noise. Now the plastic covering on the low side pressure switch has popped a leak, Damned. I waited around expecting to see it drain and need a new switch. After a while I went out to test it and after running for a few minutes shut her off it listen for the leak under higher pressure, no leak. That Super seal is great stuff, It stayed in there through the Es 12 conversion and plugged the new leak in the switch.

I now have it blowing ice cubes. It cools down in the low 40's on high fan speed. On speed 2 it reaches 30 degrees before the compressor shuts down. This must have to be an issue with my thermosat install not conducting properly on the evap., but I'll take it.

If I had it all to do over again. I would have flushed the system, drained the compressor, Vacuumed it down and loaded R12, then added a can of Super seal to fix the Evap. leak and insure not no seals are going to leak. The evap. leak started all of this.

I have used Super seal on friends cars facing $1500 A/C repairs and they never leaked again. Why spend alot of time on an old car if you can buy R12 for $30 per 12 ounces from Refrigerantsales.com in Ind. Why put all this time into conversions and adapting to larger condensers and all the rest if you can spend $100 on r12 and $50 on super seal, and have original performance with the old hoses and oil. They are really very cold A/cs in these cars.

But then, I now have a better education, to know all of this first hand.

So, if you have an E30 in need of A/c work, R12 is the cheapest fastest thing you can do, Super seal, or cryoseal are worth the investment even if some pros say it no good. Thye deal is, stop the leak, dump the heat. R12, sealant compounds = way less money and time.

[Jak]

Excellent update Conecaster,

When I was looking for parts to repair my system I needed a new compressor, drier, switch, and one line, IIRC. The only compressors I could find were rebuilt ones that cost $500. It wasn't until months later that I came across a rebuilt compressor for only $200. I wish that was available when I needed it, then I wouldn't have went the complete conversion route.

Where is the TXV? Its not the same as the Expansion valve is it?