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Today at Atelier Kaz - Private NSX Enthusiast, ex-Honda R&D engineer with F1, Indy/CART background

AC Refresh 01

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Started to work on my NSX for the major A/C Refresh.






About 4 years ago, I started noticing the slow leakage from my evaporator.
http://www.nsxcb.co.uk/entry.php?784-A-C-Evapo-Leakage







It was such a small leakage that I didn’t even had to top up the refrigerant for years.
However, the leakage got worse over the time and especially this year,
the leakage has accelerated that I started to get not so cold air inside the cabin.


I was worried about losing the compressor oil too much with reduced refrigerant circulation that
I decided to disable the compressor itself.







Well, last month, to my surprise, I found out that there was no more refrigerant left in the system;
http://www.nsxcb.co.uk/entry.php?1805-I-must-fix%85




Very bad news because there is no positive pressure to prevent the moisture getting inside the a/c system and
now it can enter freely from wherever the leakage at the evaporator.


I was planning to flush the a/c system any way so no big drama but
just worried that it could cause further damages as
the moisture plus a/c refrigerant/oil would produce acid.




While removing the dashboard, I hope I can service my gauge unit and the SRS unit as well.







Thank you to member flyingsniffer for letting me use his a/c flushing kit.
I actually bought (supposed to be exactly) the same kit from the same seller so that I can use it for other purposes.


His kit on the left and mine on the right….


I didn’t even receive the spare o-ring or the rubber nozzle…
My gauge is not zeroed at all…..



Not an issue as I'll be using the regulator at the compressor to adjust the inlet pressure but
probably I'll use flyingsniffer’s kit as the bottle construction looked better.








Over the last 22years and over 150K miles, I replaced my radiator several times.
It’s a consumable parts, just like the eng oil filter.


In order to replace the evaporator, I must first drain the coolant as the heater core is inside the same unit where the
evaporator sits so already bought the Koyo radiator and the coolant hoses, etc.


Unfortunately, there is one parts on back order until the end of this month and although I already have one in stock,
I must keep it for the other owner because Honda already delayed the estimated delivery schedule twice….


Although there is no sign of leakage from my radiator,
still, after looking at the state of the core fins,
I really want replacing it so something to be done in the future….





For the similar reason, I already purchased the 2 x a/c pipes sitting in front of the radiator.
They are exposed to the impact from the stones, debris, etc so ideally,
you want replacing them at the time of a/c refresh.







Unfortunately, the fitting at the R & L a/c condensers are known to seize as
they are also exposed to the road debris, salt, water, etc.

As they are aluminium, if you force it, you will simply strip the thread and
being forced to replace the entire condenser.


Not too expensive but time consuming as you will be removing the front bumper.

It’s my policy not to touch the front bumper unless I really have to because
adjusting the alignment is so delicate that even changing the tiny amount of torque
will affect the gap.



Although I have the new pipe, I didn’t feel comfortable after applying big torque so
going to leave the 22mm fitting….


Not easy to flush the condenser without disconnecting this thick pipe but
better than being forced to replace both condensers.










Comments

  1. unclebob's Avatar
    where did you purchase the flysniffer aircon kit please kaz?
  2. Kaz-kzukNA1's Avatar
    Hi, unclebob.

    I got the information from flyingsniffer and bought it from seller 'engineering-uk' on ebay UK with item description as 'Air Conditioning AC System Flush Flushing Kit'.

    At the time of writing, this is the current listing but the link will expire in about 20days;
    http://www.ebay.co.uk/itm/AIR-CONDIT...IAAOSwInxXMI-g

    As mentioned, you may receive something different from the listed photo but not much of a problem if you know what you are doing.
    Please just double check the construction of the container and o-ring as you will be dealing with continuous high pressure air.

    I also bought flushing solution from different place as I was not sure of the chemical used on the fluid came with the kit.
    Please never use compressed air on alone for cleaning the a/c pipes, system, etc. You could catch fire.


    Kaz
  3. unclebob's Avatar
    hi kaz

    hope u r well?

    got round to topping up my ac today, the guage initially showed the pressure to be slightly below 25psi so as per instructions i started to fill the refrigerant all was going well wen suddenly the guage needle dropped to zero from where it has refused to move. i can find no evidence of a leak anywhere condensors seem to be in good order, fans come on when ac is switched on, not sure how to tell if the compressor is engaging? when the engine is switched off the guage needle moves to around 50psi, but if i start the engine it drops back to zero?

    im using the halfords self top up kit and guage made by stmp

    any ideas or suggestions kaz?

    aijaz
  4. Kaz-kzukNA1's Avatar
    Hi, Aijaz.

    Not enough info but are you just topping up the system?
    But then it doesn't make sense why you asked about the ac flushing kit last summer as per 1st comment.
    May be you serviced your ac system last year but already lost some refrigerant and in need of top up within a year???

    By the way, these DIY kit is only good for a quick top up on a system that lost tiny amount of refrigerant over many years.
    There is no guarantee that you won't let atmosphere into the system by using it so you really want to minimise the use of it.

    You can tell whether the compressor is engaged or not by looking at the CL.
    The outermost metal disc will be spinning if the compressor has engaged while the engine is running.
    Our NSX uses classic swashplate fixed displacement type compressor, unlike the modern electrically controlled variable one so easy to tell the On/Off status.

    Not enough info and I presume your DIY kit was connected to the suction side (Lo pressure port) of the compressor so all I can say is that if your gauge showed zero (and probably it doesn't have negative reading so you won't be able to tell whether it went negative pressure or not), that means there was no refrigerant in the form of gas left at the suction side of the compressor when it was engaged.

    This could happen if you have severe blockage at the upper stream (if your gauge can read negative pressure, probably it would have shown it) or you have so little refrigerant with some upper stream blockage that all of the gas form was sucked back to the compressor after leaving the evaporator (very unlikely).

    So, you need to tell what made you think about topping up and what has been done so far including the reason why you asked about the flushing kit last summer.
    Ideally, you want to use the proper manifold gauge to start with but if you don't know how to use it, probably best leaving it to the AC specialist as ac failure would result in huge cost for both the parts and the labour.
    AC system is one area that you must act at the first sign of the failure.

    Kaz

  5. madras's Avatar
    Hi does anyone know a part that can be fitted for the drier as it is available from Honda but it's £350-400 I think. I did order a hella one but it got cancelled as no longer made.

    Thanks.
  6. madras's Avatar
    actually I found one option on another thread from compressortech.co.uk - RD19115 rec/drier 90 deg No4 Rove £40.95 - will try them, although any other suggestions for what fits would be helpful.

    Thanks
  7. NSXGB's Avatar
    Madras, I think I have 2 spares, drop me a PM if you are interested.
  8. Kaz-kzukNA1's Avatar
    madras, get it from NSXGB above or just order 4seasons 33412 through Rockauto.
    Detail here; http://www.nsxcb.co.uk/entry.php?232...r-33412-part-2

    Even using FedEx, probably something like GBP25 - 30 including import VAT.

    You can use discount code as well; http://www.nsxcb.co.uk/showthread.ph...44841152619337

    Rockauto was VAT registered even before Brexit so you pre-pay the tax at the time of order nothing to pay afterwards.


    Kaz
    Updated 16-04-2021 at 10:25 AM by Kaz-kzukNA1 (discount code included.)
  9. madras's Avatar
    Hi thanks for that!

    NSXGB - I did try and message a couple of times but it doesn't seem to be in my sent folder? Maybe you can message me please?
    many thanks,
    Chris
  10. NSXGB's Avatar
    PM sent Chris.