Open Road

Do we have any trusted sources for upgrading the AC condenser?

86.5 Auto.

I found this, but I'm not sure I trust it.

https://autoacsolutions.com/products/pa ... hatgpt.com

So far the only other unsolved issue is how to handle the hard-line with the crimped hose that's all but impossible to remove.

Everything else is ordered, plan to start the job next Thursday.

Look here to see what they may have:

https://griffiths.com/porsche/air-condi ... rsche-928/

They offer OEM and Kuehl compressor components Don't know if Kuehl makes 928 condensors. Griffiths has AC kits and hoses.

Always heard good things about Griffiths/Kuehl, but have not used them...yet. Stock system works excellent (I'm in Florida, USA, also an 86.5 Auto) when all the many components are up to spec.

At this point I'm going to leave the stock condenser in the car.After much consideration, I'm going to convert to 134a.

Afterwards if the stock condenser isn't up to the task it'll be somewhat lesser hassle to change.

I'm hoping I can convince a local AC shop to crimp new hoses in place on the captured hardline. Failing there I'll be looking for the tooling to do it myself.

the aftermarket condensers that Griffiths sells are a barely fit version and mount crooked. that parallel version has too much flat metal on the ends blocking flow to the radiator in my opinion.

The options are getting thin as the 5 speed condensers for the S4/GT's hae been NLA for a while now. & the auto versions look like crap with the top 3-4 inches of the radiator showing.

If you later decide to upgrade (?), here's another source:
https://www.coolerclassics.com/product- ... 303-ac4970

I have NO experience with them, just stumbled on them when looking for an '89 replacement.

NLA parts are getting to be a pain on these cars.

I'll look at removing my current condenser and taking measurements for adapting universal fit parallel flow.

I finally got to removing the old condenser and taking good measurements. I'd ordered a 14x20 universal more or less blind, looks like I undersized it by ~12%. Fuck.

Measuring now, I'm betting I can fit a 16 x 26.



In other news, if all the R-12 leaks out on it's own you don't have to recover it.
Nothing when I pulled the high side schrader valve, so I've got a significant leak somewhere.

Do you have "rear AC"? If so, check that system for leaks. I had a leak there in my 86.5 and have heard the same from others.

The other leak was caused by a line that was not secured properly and was rubbing on the motor. Lovely line hole that causes over time....

rear air has 8 or more places for refrigerant and oil to leak out. 4 under the car, and 4 more at the expansion valve under the cover over the transmission hump and their might be 2 more under the seat but i can't remember and I removed mine so........

When sizing the condenser keep in mind the headlight motor and rotating arm.

maddog2020 wrote: ↑Mon Jan 12, 2026 8:06 am rear air has 8 or more places for refrigerant and oil to leak out. 4 under the car, and 4 more at the expansion valve under the cover over the transmission hump and their might be 2 more under the seat but i can't remember and I removed mine so........

When sizing the condenser keep in mind the headlight motor and rotating arm.

I strongly considered deleting the rear air.... That might still be on the table if the evaporator is bad.

The two fitment issues are bringing a custom hard line around to the receiver drier on the bottom and leaving enough space for the headlight mechanism on the other side. It was nice of Porsche to make the bottom mounts of the condenser angled.


Does anyone have the exact sizes of the captive lines with the crimped hoses? I've got to go back to work for two weeks and I'm making another order.

I thought about making some adapter brackets to make the mounting points flat. The problem with the rear air is the lines that go under the car are the lowest point in the system and oil tends to pool in those lines when not using the rear air. I suspect that 928's with rear air will eat compressors more often than those without. If the oil isn't circulating then the compressor will wear pre maturely.

Best thing to do with rear air is to remove it and plug the lines under the car at the "Y"s.

Then use all that A/C space for stereo equipment

if you plug under the car you can create pooling for oil and contaminants. If you are going to remove the rear air, it's best to remove the lines and either weld them up where the T is on both or just replace with no rear air lines. Where they branch off is on the firewall before they go under the car.

maddog2020 wrote: ↑Mon Jan 12, 2026 9:17 pm if you plug under the car you can create pooling for oil and contaminants. If you are going to remove the rear air, it's best to remove the lines and either weld them up where the T is on both or just replace with no rear air lines. Where they branch off is on the firewall before they go under the car.

Of the several ways to plug the lines all of them are better than leaving (a non-leaking) rear A/C in and never using it - which is how the oil pools in the first place. If you plug at the junction you've cut the volume of pooling by 90%. If you cut off the branch and then plug or weld you've cut the pooling volume by 99%. But the 90% solution is very quick and cheap: you can buy plugs specifically for this.

Real men pull the engine and replace the engine bay lines with the non-rear-AC versions.

you can remove the rear ac lines without pulling the engine. if they aren't going back in the car then you can bend them enough to get them out and the non rear air lines go in without pulling the engine. I did mine with the engine out but I helped another 928er do it with the engine in the car.

the key is to find and acquire the no rear air lines 1st. they are getting hard to find here in the US. I found mine on german ebay.

What's to stop you just buying a roll of #6 & #8 stainless steel line in that case?

https://vintageair.com/hose-kits-and-fi ... line-kits/

I'm keeping the rear air unless the evaporator fails pressure test. Mostly because I'd like to sell the car and move to a newer 911 and it's easier to explain than a delete.

This looks like it should fit to add in a high pressure switch:

https://www.partsgeek.com/mr73mf4-merce ... witch.html

The final decision on the condenser. The maximum clearance is roughly 25" wide by 16" high. Need one that fits within that space by overall width.

Someone done been here before. I don't like it. I think I found my leak already.


Now I don't know much about HVAC but....

So now, I still have to fish that line back up out of the engine bay as far as I can, cut the JIC fitting off, and use,the recently much more expensive, muggy weld to braise an appropriate SS #6 o-ring fitting.


Why would you use JIC?! They sell the appropriate fittings. You can just buy them.

That's the fuel supply line in your pic. L/P A/C aluminum hardline beneath it.

worf wrote: ↑Fri Jan 30, 2026 7:11 pm That's the fuel supply line in your pic. L/P A/C aluminum hardline beneath it.

You wish you were correct.

The fuel line doesn't plumb into the AC receiver drier...

Or, wait, did some one cut the H/P line and weld that fitting to it? WTF?

worf wrote: ↑Fri Jan 30, 2026 7:14 pm Or, wait, did some one cut the H/P line and weld that fitting to it? WTF?

I had to walk away for the day.

I guess someone played "make a line" win AN- fittings and a flame wrench?

worf wrote: ↑Fri Jan 30, 2026 7:17 pm I guess someone played "make a line" win AN- fittings and a flame wrench?

It's silver braised. They did a bad job of cleaning the flux off the other "captive" side, part of why it's so corroded.

Now I know who the PO of this car was, but I'm going to give them the benefit of the doubt that they wouldn't do this.

Ominous.

What was that about deleting the rear air again?

Fox_ wrote: ↑Sat Jan 31, 2026 3:13 pm.
What was that about deleting the rear air again?

https://coldhose.com/products/10-female ... 8819886335

Update:

Entire refrigation circuit with the exclusion of the front evaporator has been stripped from the car. I damaged the low pressure aluminum line fighting a extremely stuck connection near the low pressure service port & suction hose on the compressor.

After that the cutoff wheel made an appearance.

I'm just going to run barrier hoses + heat sleeve. This will improve serviceability and should be just as good as the hard-line as long as I route it neatly & protect from chafing.

The only thing I can't visualize is how I'm going to do the low pressure service port after losing the rigidity of the hard line there.

Now we order parts because you can't buy anything locally and try again after two weeks away for work.

Almost a week out so ordering parts again. I brought some pieces with me just to double check measurements.... Not only trying to make it work, but make sure it doesn't look like trash.

The original high pressure hard line is 10mm OD. Where it enters the expansion valve is a #6 male. I have saved a portion of this hardline that connects to the expansion valve and exits the firewall(?). Since the OD of this line is 10mm it's not compatible with standard #6 weld on fittings. #8 weld on fittings accommodate 9.5mm OD. I will have to make this work. From here I will need a #8 to #6 reduced diameter straight hose crimp. From here I can run #6 barrier hose to the #6 discharge on the drier.

From where the low pressure side exits the expansion valve is #8 hard line that going into a #12 fitting on the fuel cooler. I have retained the fuel cooler and this hard line as is. Exiting the fuel cooler is a #12 male. I need a #12 female to #10 barrier hose straight fitting. From there I can make the run to the compressor suction line. Somewhere in this run I have to install the low pressure service port. For whatever reason there is again a #12 fitting on a #10 run here.


On the condenser. On the original Porsche design the condenser inlet and condenser outlet are both #8 fittings that exit up & down. The generic parallel flow condenser has a #8 inlet at the top that's parallel with the ground vs the original perpendicular. As well the discharge at the bottom of the new condenser is a #6.

I have to bring the discharge 180° back then 90° up if I want to keep the original style drier. The first plan was to run custom hardline that was the unholy communion of the shapes of sideways U and backwards L. However, finding fitting to adapt the #6 to #8 in a short hardline run isn't easy.

The other option is a 180° #6 crimp fitting, a loop of #6 barrier hose that comes back around into a #8 to #6 90° crimp fitting. These fittings are available.

Finally I need to route the top inlet 90° down and hope I have enough room.

The original condenser mounts from the bottom, to an angled area. The universal condenser I found only has mounting points on the sides. I'm hoping this mounting will be a simple as a lopsided 'U' shape where one leg is bent +90° and the other leg bent -X° to match the mounting holes.

Plan on wrapping the long barrier hose run with:

https://www.designengineering.com/heat- ... -wrap-exo/

or similar due to the proximity to the exhaust manifold.

I'll order some slightly larger cushioned Adel clamps to accommodate the hose and use the same mounting points as the hard-line.

A story in three parts.




Guess who has to go back to work Tuesday morning for two weeks?

I'm not paying for this.

That is VERY uncharacteristic for Coldhose. When i've ordered stuff it's always shipped within two business days.

worf wrote: ↑Sat Jan 31, 2026 3:20 pm

Fox_ wrote: ↑Sat Jan 31, 2026 3:13 pm.
What was that about deleting the rear air again?

https://coldhose.com/products/10-female ... 8819886335

Folks, my assumption with the above post was that it :
- would create an awareness that there were companies make block-off fittings
- might spark a conversation about using block-off fittings for the rear A/C.
- make folks realize that either two or four plugs, of two different sizes, are required.

I DID NOT THINK that folks would just order that part.

This was very sloppy of me and I apologize.

I will endeavor to make a dedicated thread on how to block off the rear a/c in the next day or two.

worf wrote: ↑Thu Feb 19, 2026 3:35 pm
Folks, my assumption with the above post was that it :
- would create an awareness that there were companies make block-off fittings
- might spark a conversation about using block-off fittings for the rear A/C.
- make folks realize that either two or four plugs, of two different sizes, are required.

I DID NOT THINK that folks would just order that part.

This was very sloppy of me and I apologize.

I will endeavor to make a dedicated thread on how to block off the rear a/c in the next day or two.

If you're talking about me,

I'm completely replacing -all- hard lines in the car due to damaging the aluminum hard line when dissembling. Cold hose was the only site that had the somewhat specialized fittings that I needed. If something looks odd in the parts list, it's a compromise on parts availability. I had to use standard #10 hose for a reason.

Fox_ wrote: ↑Fri Feb 20, 2026 3:12 am If you're talking about me,

Not specifically.

But more plugs are required.

See new thread I created last night.

I just have to say...

Coldhose.com has, single handed, wasted months of my time sending the wrong parts out.

-10/10

I hate when that happens.

I am very late to this party, but I will post anyway.

I have an 14 x 20 parallel flow condenser in my 86.5



Here is what the lower connection from the condenser to the receiver dryer looks like:



I kept the original hard line to the evap and brazed EZ-Clip fittings on.

More gory details are in this thread: https://rennlist.com/forums/928-forum/6 ... eed-2.html

A bit of warning - with r12 my evap freezes up pretty regularly. I am hoping that part of the problem here is too much oil in the system, for which I am totally responsible. My plan this spring is to flush out the system and be very conservative with oil when recharging. After that I may be diddling with the freeze switch to see if there is a sweet spot that minimizes freezing but still provides the arctic blast my wife requires. It is entertaining to see little ice chunks fly out of the center vent after a 15 minute AC off thaw interval. I don't have rear AC, but that extra evap could come in handy.

Luckily I live in aluminum boat land and a shop 10 minutes down the road bailed me out.

Cold hose still sent the wrong part twice, but they're also about the only ones that carry #12 ac fittings

Revised 2/10.
This adds two unnecessary leak points, but the bead lock fitting I needed seemly isn't in stock.

Eplebnista wrote: ↑Fri Apr 03, 2026 12:13 pm A bit of warning - with r12 my evap freezes up pretty regularly. I am hoping that part of the problem here is too much oil in the system, for which I am totally responsible. My plan this spring is to flush out the system and be very conservative with oil when recharging. After that I may be diddling with the freeze switch to see if there is a sweet spot that minimizes freezing but still provides the arctic blast my wife requires. It is entertaining to see little ice chunks fly out of the center vent after a 15 minute AC off thaw interval. I don't have rear AC, but that extra evap could come in handy.

Looks great! Love the solution for the condenser outlet to drier.

I spec'd the largest possible condenser that would physically fit. I have 1/4" or less between the headlight arm and the side of the tank!

Eplebnista wrote: ↑Fri Apr 03, 2026 12:13 pm A bit of warning - with r12 my evap freezes up pretty regularly. I am hoping that part of the problem here is too much oil in the system, for which I am totally responsible. My plan this spring is ...

Too much oil reduces A/C efficiency. Your r12 system with one exception is working like it should: *ice cold.* Don't waste r12 messing with the oil level.

The exception is your anti-freeze switch. They have the life expectancy of a fruit fly (in a 928 context.) Rarely do they last 10 years. 5 years is typical.

They are adjustable. They are testable. Test yours. Buy a new one as indicated. Test it. Adjust it. All can be done in the kitchen.

Progress towards something.

I'm not super pleased with how the hard line turned out. We have some compromising due to parts availability. Condenser is sitting on rubber feet, mount has drain holes.

Evaporator flushed. Expansion valve replaced. High side stub end in place. Fuel cooler in place, fuel lines hooked back up.

To do:

Mount new compressor.

Install condenser assembly, measure & cut & crimp front side of new hoses. Install low pressure service port.

Fabricate top condenser mounting brackets.

Vacuum test, pressure test ~150psi.

Looks good!

I am surprised you had a bad experience with Cold Hose. I did not and ordered a lot of stuff.

Switching back to the freeze switch. Mine works, I have tested it. I guess it is obvious that I have set it too low. While I figure out how to have a controlled source of cold water, does anybody have a suggestion for what temperature I should set the freeze switch at?

Eplebnista wrote: ↑Sun Apr 05, 2026 8:08 pm Looks good!

I am surprised you had a bad experience with Cold Hose. I did not and ordered a lot of stuff.

Switching back to the freeze switch. Mine works, I have tested it. I guess it is obvious that I have set it too low. While I figure out how to have a controlled source of cold water, does anybody have a suggestion for what temperature I should set the freeze switch at?

I set mine to 34 to 38. Seems to work for me with my thermometer and ice water bath...

The audacity: Dry Fit: I am going to make a new bracket here to better mount the high side AC hard-line. Finished AC lines: I could not have fit a bigger condenser:

Nice work. It gets tight in there real fast. I am sure you thought of this but be sure to fabricate your lower mounts to be stout enough to keep the condenser off the radiator.

Off my 6 week 911 affair.... My project to free time ratio is quickly becoming a problem.

Everything is plumbed up 100% for the first time.

Unfortunately I seem to have an extremely slow leak somewhere. Its fast enough to be a problem, but slow enough that I'm going to struggle to find it.

Does the oil have UV tracer?

3psi drop in 20 hours.

I'm going to tell myself that's a temperature change and send it, started reassembly today.

Well, psi drop, or psi numbers after a few days?