Air con re-gas/top up?

[Philip]

Alert! Cheat-Alert!

Tell me more??

[britlude]

Hmmmmm it's desirable to change these when going from the now illegal R12 to the R134, but not necessary.... As I understand it, the R12 lubricant oil doesn't dissolve in the R134 fluid so the system should be flushed to get most of it out then filled with R134 and the appropriate oil... Mines been ok since this was done in 2014, but I'm changing the pump soon as it's beginning to get noise... Now this may be to do with the AC fluid change, but more likely to do with the 150k miles...

[goldnsx]

There's no reason to change (expensive!) parts while going from R12 to R134a except a new drier.

Or did your compressor blow up?

[Philip]

No, the compressor seems fine. The garage said they cannot re gas with R12 anymore?

[goldnsx]

R12 is forbidden in some small 'environmental-friendly' countries while they juggle with Freon-cans in the backyard of some US households. Double moral at its best.

The problem the shop has is to suck the R12 out. Not all are willing to do this as they need a separate station for it as you should not mix R12 with R134a. As R12 is forbidden not they might have disposed the old station. That's why most say they can't do it.

That's why it's a wise thing to use R134a. A retrofit kit and a new trier (R134a version since 1993 in the NSX) is needed only, nothing else (maybe 2 new valve inserts from eB China). If they still want to throw more parts at the car it's better to find a better shop...

[Kaz-kzukNA1]

Hi, Philip.
Can't remember whether your system was already converted or not.
Could you check the shape of the charge valve?

The easiest one to check is the high side valve located behind the R-side headlight marked in yellow.

For safety reason, if you are not familiar with the HVAC system, best not to remove the cap.
You can tell the shape of the valve without removing the cap.

If removing the cap, please wear protective glove and glass, cover the valve with the shop towel in case of sudden refrigerant leakage.
If you don't have protection glass, at least move your face away from the valve.
You could experience ice burn or even lose eye sight.


Which type (R12 or R134a) of charge valve do you have on your existing system?
If retro-fit kit was used in the past, you will see extra parts (adaptor fitting) on top of the original valve.

Normally, you can find a sticker with big '134a' logo under the bonnet if converted or in use from the factory but it can peel off from time to time.
Depending on your answer, it will change the direction of the further recommendation.


Kaz

[Philip]

Thanks Kaz, here is a pic. The cap is black

[Kaz-kzukNA1]

So, unless someone removed the adaptor or created the adaptor joint on the equipment side (seen it done in Japan....), your system is still the original R12 and you have either the R12 or R12 compatible refrigerant in the system.
The brown stain markings at the sight glass is very likely to be the contaminated mineral oil (R12 spec) or something similar.
Basically, not normal.

If this is in Japan, the R12 refrigerant can be purchased legally but no longer allowed to be manufactured or exported.
Still, I was told that during the manufacturing process of certain products, R12 is inevitably produced so it won't disappear....


As goldnsx mentioned, probably the place you visited didn't like the idea of recovering the R12 refrigerant from your system.


Anyway, in UK, there are several options for you.

1. Alternative refrigerant
I'm not fan of this but I think several owners are using it.
Not sure where you are based but there is a company called [Bee Cool Air Conditioning Services (ACS)] in Northampton, NN16 8LD where several NSX owners have already visited.
http://www.bee-cool-aircon.co.uk/

I think Mike - @sorepaws is one of them who had the alternative refrigerant charged into his original R12 system.
May be PM him or just contact Bee Cool if you live nearby???


As long as your compressor, exp. valve, etc are tired but operating fine, you can re-use them.
You are very likely to be asked to replace the drier/receiver.

Although you have fair amount of leakage and thus, worth considering the Retro fit as per next section, this will be the cheapest and quickest option for you to keep moving before moving to the next stage.


2. Retro fit - basic
If your compressor is still operating fine (for now) and can be re-used, considering the contamination, I don't think it's worth the next step 3 (Retro fit - advanced) unless you are ready to flush the entire system and replace the compressor, etc.

Strictly speaking, due to the boiling point difference between R12 and R134a, you need higher energy exchange capacity at the condenser for R134a.
Therefore, the advice from your a/c specialist is somewhat correct but unless the fins are smashed or the fitting thread is stripped, you can keep using your existing R12 spec condenser.
It's the matter of efficiency and how far you want to go but for this basic retro fit purpose, I won't replace it.

During the Honda Refresh program at the factory, if the existing R12 system was blowing cold air with the compressor making no abnormal noise or no major leakage, all they do is to install the adaptor charge valve, replace drier/receiver and put PAG oil designed for the retro fit purpose.

They won't flush the system.
They will re-use rest of the original R12 components such as the compressor, condenser, exp. valve, o-ring, flex hoses, etc.
For your reference, I don't like the OEM adaptor charge valve included in the retro fit kit.
Honda may have already changed it but I always recommend the one from Denso Japan.


When retro fit was first introduced in the early 90s', there were lots of scary negative stories.
However, as the history proved, while it's ideal to have clean system and replace the parts to R134a spec, for mainly cost and time saving purpose, you can keep using majority of the R12 parts even at the time of converting to the R134a refrigerant.

The old R12 spec mineral oil will stay inside the lower part of the system as it can't travel via R134a refrigerant or it will be neutralised and remain as a certain 'debris' if specific PAG oil used at the time of conversion.
It will reduce the efficiency slightly but most likely, you won't notice it.


If your existing system is healthy with no major leak, this option would last for many years.
However, if your compressor was already making noise or the system have major leakage (resulting in reduced compressor oil amount), there were lots and lots of premature failure reported within a few years after the conversion.


3. Retro fit - advanced
You are going to replace at least the compressor, exp. valve, drier/receiver, o-ring, shrader valve, etc and must flush the entire system, ideally by disabling the exp. valve needle.
I'll be doing this for another owner soon as the owner was forced to replace the evaporator any way.

Time consuming, expensive and require some NSX experience so not everyone's cup of tea.



Hope you can find the suitable option for your target.


Kaz

[britlude]

can you not seek a second opinion from another air-con service place that is less intent on ripping off its customers? the mobile ac guy that did mine knew the score, had the conversion kit (it's only screw on adaptors) and away he went!!!

the AC techs have to deal with removing R12 on a regular basis i'm sure

[Philip]

Thanks for all the advice guys, especially Kaz �� looks like I will be off to Bee-cool soon.