[s-cars] a/c capacity...recharge

[James C. Mairs]

Once again thanks for all the replies Tom and others.  Side note I got lucky
with VIN splits or whatever, my entire system is R134 not a converted R12.
So no need to find a seller for R12 canisters, as any local Parts place will
carry the 12-14oz cans.

My various responses are included in the post below.

Feeling better about this... Shame though it wont be done for the weekend,
and Friday at least here is supposed to reach upper parts of 95 humid and
t-storms.... Is there anything worse about a black on black car, in 95+
degree heat and having to have the windows up?

<Gasp Choke>

Thanks again folks!


-Jim

> -----Original Message-----
> From: Tom Green [mailto:trgreen at comcast.net]
> Sent: Thursday, August 02, 2007 9:01 PM
> To: s-car-list; jmairs at cetaq-americas.com
> Subject: Re:[s-cars] a/c capacity...recharge
> 
> There are no VAG specific tools used to evacuate and charge the
> system Jim, even at the dealer.  The high pressure port fitting fits
> on a standard
> automotive a/c gage set, Kent-Moore or similar, or the newer recovery
> units with
> integral gage set.  Your HVAC friend should have no trouble
> evacuating and
> charging the system using the standard high pressure port.  There may
> be some
> question of how much oil to add back to the system.  With your system
> already
> back together you won't be able to drain the compressor to change the
> oil and
> check quantity.  If you didn't drain or blow any oil from the
> compressor, I would
> assume it is still full and only add the make-up for the accumulator,
> evaporator
> and condenser, or 2 oz according to Bentley.  If it was drained, add
> 2.7 oz in the
> compressor through the drain plug and the rest through the gage set when
> recharging to make up the 8.5 oz total.  There are some universal
> oils out there,
> my compressor has pag 100 in it.   Oh, the drain is on top of the
> compressor, so
> you can't drain it if it is bolted to the engine.

[JCM] 

Excellent input on the 2oz, I didn't drain the system of PAG when I was in
there doing all the other work.  Good or Bad, I couldn't determine if it was
going to help me to do so, so I didn't.  I know when I was clearing a few
separated lines, there was trace amounts of PAG fluid for sure.  I never did
remove the lines at the back of the compressor though.  So perhaps 2oz and I
will be good to go.  I guess I will be aware of the issue that it may not be
8.5 oz but at least it will be as close as possible without over filling.


> 
> An accurate scale to measure the amount of refrigerant removed from
> the tank
> should result in around 100 psi on the gage, and 290 psi operating
> (close tank
> valve first).  The electric fan should operate and the engine fan
> clutch locks up
> when the engine gets to operating temperature.  Turn the a/c to low
> and recirc
> and you should have cold air at about 40 F.
> 
> What your a/c friend may not like is there is no service port to
> check the system
> balance and and fill and fine tune the system while operating, so you
> have to
> shut down, cool off the system after you've got it really hot
> checking it out, just
> to add another 1/2 oz or so to fine tune the operating pressure and
> duct temp
> for optimum performance.  I guess you could put the gage low pressure
> hose
> connection on the compressor fitting for a reading, but the one you
> want is at
> the orifice, and don't even think about adding liquid refrigerant
> there.  You need
> to know what you are doing to add it at the orifice so no liquid
> reaches the
> compressor.


[JCM] 
Ok that makes a lot of sense, as he mentioned the time to do this should be
only a few minutes for evac'ing the system, then filling but he said he may
need the most time doing final adjustments.  I will print out this email so
he can take a read through it and do as he sees fit.

One of the only things that comes to mind at this point was he mentioned I
may want to look into R134 specific to higher mileage cars, he doesn't stock
this version but mentioned it would be worth tracking some down.

> 
> The threads you have been following and a friend with HVAC tools should
> make this a no-sweat (pun intended) operation.  The extensive threads
> are
> just guys wanting an easier way because they don't have a HVAC
> friend, and
> just need a little make-up after 10 years operation.  Bentley has
> extensive
> coverage for a/c diagnosis and repair.


[JCM] 
Well that's good news, it took some time for me to track down a PAPER
version of the Bentleys.  I just don't see the value in a shop manual on
DVD...  The manuals should be here hopefully tomorrow (Friday).  Which will
give me some time to read over the various tests, and charge specific texts.
As far as easier for the future, I know my friend asked if I wanted to plumb
in a Low side T fitting to make this easier in the future.  I hadn't
answered him on this yet.  Going to try to get my ducks in a row first on
the normal system, have him take a look at it (Lives a bit far from me) then
after he has a chance to see what he is working with, I will probably order
whatever is needed for the next recharge or such.

> 
> Check the links I just gave to Floyd on his oil pressure and other
> questions.
> The corporate history of several years of s-car ownership and repair
> are on
> those sites and a few others.

[JCM] 
I think I might have missed the links you sent to Floyd.  Will go through
the email box again and see if I missed something in the threads.  That said
even this amount of conversation makes me feel a lot better about what I
need to get done to the system.  Your pun as you said was also made by my
friend, keeps telling me to stop sweating it, and just get my car to his
garage.  My interest in understanding this is one for my own knowledge (I do
all my own repairs, bar exhaust and tranny work, and I am just trying to
make sure I have an understanding and all the materials needed for this so
as not to waste my friends time when I get there and am missing 1 or 2
stupid things that will put an end to this project.
 

> 
> Tom
> 
> > Date: Thu, 2 Aug 2007 14:55:21 -0400
> > From: "James C. Mairs" <jmairs at cetaq-americas.com>
> > Subject: Re: [s-cars] a/c capacity...recharge
> > To: "'s-car-list'" <s-car-list at audifans.com>
> > Message-ID: <01c601c7d536$ada4d6c0$0b03a8c0 at CeTaQJCM>
> > Content-Type: text/plain;	charset="us-ascii"
> >
> > Greetings Tom,
> >
> > Excellent information, I have been following the AC threads for
> > some time
> > now, trying to determine if anyone actually has followed through
> > with a
> > recharge without going to the dealer.  Lots of information but not
> > a lot of
> > BTDT with answers...
> >
> > Appreciate the info, side note the charge in the system was working
> > fine
> > before I tore the entire front end out and apart for a head
> > rebuild, coupled
> > with a lot of while I am in there fixes and replacements.
> >
> > AC in the car was working before breaking open the system, however
> > I wish I
> > had gone through the diagnostics to see how well it was working
> > (HVAC codes
> > and such) before taking it apart.  Alas a compromised head was
> > leading me to
> > not wanting to run the car for long periods of time.
> >
> > AC system was sealed back up after replacement of the dryer and new
> > Variable
> > Orifice Valve.  All lines separated were put back with new seals,
> > and of all
> > the lines only 1 was I able to flush completely before reassembly,
> > mostly
> > due to being to far into the project to want to spend more time and
> > money.
> > The others were just disconnected and compressed air to blow out
> > whatever
> > black sludge wanted to go flying out from whatever end wasn't pointed
> > downward.
> >
> > Hope some other folks post up information if they have completed
> > this as a
> > DIY job.  Especially the fittings and procedure when not having the
> > correct
> > VAG tools...
> >
> > Thanks again Tom, if anyone else has any links or key words of
> > wisdom to
> > offer I am more than all ears.  Or if you happen to have any good
> > archive
> > thread searches I can use, mostly looking for BTDT's or things to
> > watch out
> > for, it would be appreciated.
> >
> > Thanks,
> >
> >
> > -Jim
> >
> >
> > -----Original Message-----
> > From: Tom Green [mailto:trgreen at comcast.net]
> > Sent: Thursday, August 02, 2007 11:14 AM
> > To: s-car-list; jmairs at cetaq-americas.com
> > Subject: Re:[s-cars] a/c capacity...recharge
> >
> > Jim,
> >
> > Capacity is 21.2 to 23 oz refrigerant and 8.5 oz of Pag oil.  The
> > high presssure port on the passenger side of the condenser is the only
> > port used and evacuated and charged with engine off.  You can only
> > measure the oil charge if you drain the oil (at the condenser) and
> > change the accumulator since an unknown amount collects there.  The
> > real trick is accurately measuring the refrigerant charge.
> >
> > If the system is in good condition with all fans and flaps working
> > correctly in
> > recirculate mode, the result should be about 40 F duct temperature at
> > 95 F ambient.
> >
> > The system base pressure is 113.1 psi at 95 F (engine off) and 290 psi
> > operating pressure with a full charge.
> >
> > Tom
> >
> > -----Original Message-----
> >> Date: Wed, 1 Aug 2007 18:24:47 -0400
> >> From: "James C. Mairs" <jmairs at cetaq-americas.com>
> >> Subject: [s-cars] AC Capacity...Re-Charge
> >> To: "'s-car-list'" <s-car-list at audifans.com>
> >> Message-ID: <015801c7d48a$c4c727b0$0b03a8c0 at CeTaQJCM>
> >> Content-Type: text/plain;	charset="us-ascii"
> >>
> >> Greetings all,
> >>
> >> Bentley Manuals are in route via shipping, so I can not confirm the
> >> following, or even if its listed.
> >>
> >> Does anyone know the capacity/recharge pressure amount for a 93 //S4?
> >>
> >> I have been following the threads here as much as possible on the
> >> whole AC
> >> snow flake conversation, as well as a quick search in the archives.
> >>
> >> I have a HVAC friend who is willing to run a vacuum test on my
> >> system before
> >> recharging it.  He doesn't seem to think it will be an issue, but
> >> informed
> >> me I should confirm what amount of R134 should be in the system.
> >>
> >> He has a large amount of fittings/adapters and such, its possible
> >> we may
> >> even just plumb in a connector with a generic fitting to make this
> >> easier in
> >> the future.  If/when I come up with a solution I will be sure to
> >> post up my
> >> findings... However in the mean time sitting in 93 degree heat in a
> >> black on
> >> black S4... I have to ask...
> >>
> >>
> >> Anyone care to toss out a number?
> >>
> >>
> >>
> >> -Jim