Slow AC evaporator leak '96 LHS

'96 Chrysler LHS - California rules.

Problem: very slow AC refrigerant leak; works satisfactorily for 6-8
weeks before needing recharge. Testing under the hood is negative to
electronic sniffer and blacklight visual inspection for dye leakage.
Electronic sniffer appears to be positive inside the interior vents,
suspect evaporator section or its connectivity

Repair consideration: disassembling the dash to access the evaporator
section will be labor expensive and 'awkward'

Workaround: my mechanic is 'compatible' with my doing some of my own
recharging and he is willing to (also/alternatively) recharge with his
shop's recovery system *BUT* it is his belief that R-134a recharges
which contain leakseal are bad for his recovery system, and he doesn't
want me to use those types when I recharge.

Conflict: I would like to continue to use both my own DIY recharging as
well as periodically having him fill it up properly; but I would also
like to see if the leakseal would help my situation.

Questions: Is it a myth or not that leakseal fouls up recovery systems?
Can anyone provide me with any 'documentation' or a link of a discussion
on this subject so that I can present my arguments to him for 'allowing'
me to use leakseal? The local auto parts store sez that they've never
heard of leakseal fouling/damaging recovery systems. Is there a
difference in this context in the danger of the older leak seals for
Freon systems vs for newer 134a leak seal additives?

 

I know I'm not answering the question you asked, but I don't know if
I've heard of a single case of sealer actually working for any length of
time.

 

I am also interested in that experience information.

If you ask the stores that sell the stuff whether or not anyone ever
reports it working, naturally they say Yes. HoweverAnd, those stores
also sell refrigerant without leak seal.

And also naturally the shops that fix the systems which DIY attempts
with leak seal which didn't work (permanently) are going to see 100%
eventual failures. I would think no one would come in to the car AC
repair shop to report a system which isn't leaking any more.

I haven't reviewed the chronology properly, but I think this leak's time
between recharge is getting smaller/less in terms of weeks.

 

If that's the case, chances are a bad evaporator - it almost always is
on the 2nd gen LH's, and they use the same evap. part as 1st gens.

Also someone posted in the past that a trick for detecting a bad evap.
in a system that has the dye already in it is to check the end of the
condensate tube with a black light - if evap. leaks, the dye will get on
the outside of the evap. and get picked up by the condensate - hence
glowing inside of condensate tube. Clever, eh?

 

I'm (pretty) sure we/he didn't look there with his light. Good idea.

The next time I'm in there to chat with him, we can take a peek.

I don't know my generations, so I don't understand this very well:

Does this mean that the 96 is a 2nd generation, but the evaporator is
'no better' than the earlier generation or what?

 

Yours is 1st gen. 1st gen was '93-'97. '98-'04 was 2nd gen. (no 300M
in 1st gen, and not until '99 MY). 2nd gen was new body style and
engines and many re-designed mechanical parts (same tranny).

 

Oh, I get it now. You are accustomed to diagnosing 2nd gen AC problems
and they are frequently evaporator -- which is the same evaporator part
as the previous gen/models.

Thanks.

 

He's correct. Also, the leak seal products are bad for your AC system.
Two types of sealer; the ones that harden plug the passages in the
evaporator, condenser, orifice tube, accumulator, compressor, muffler.
The ones that swell seals are ineffective on an evaporator or other
hardware component and they also damage the system by softening the
inside of the hoses (they eventually turn to goo) allowing the hose
material to contaminate the entire system.

AC sealer products are for those who don't know any better.
Once installed, you can pretty much consider the entire system 'totaled.'

This makes no sense. What is the advantage to alternating back and
forth?

Not only will it not help, it will increase the cost of a proper repair
drastically.

No myth.
In addition to it fouling recovery equipment (which the customer should
be on the hook for) if I dug around thru my bookmarks I could find links
to a Ford pick up truck that had sealer installed, the explosion took
out the compressor, the condenser, the radiator and one of the valve
covers on the engine. The sealer has installed by a HVAC "pro."

There is no shortage of stories out there that claim "it worked great."
More important is what they're not telling, i.e., that they system
eventually failed catastrophically, or that subsequent repairs involved
replacing every component in the system, or that they scrapped the car
shortly after.

And how would they know? They're not in the repair business, they're
not in the equipment business, they're not in the AC business. They are
in the ring up your purchase business.
By and large, parts stores are bad places to go to for advise.

None what so ever.

I can tell you from 40 years of experience, 30 of them doing AC repairs
that short cuts never work and more often than not, back fire and wind
up costing much more than a proper repair.

 

My mechanic is very reasonable in his charges for me. Now that he has
completed all of his troubleshooting to his satisfaction, he is
comfortable with just evacuating and charging the system and charging me
'modestly' for the r134a. used, and he buys it a lot cheaper per pound
in his tank than little cans at the retail consumer auto parts store.

My personal experience with recharging with a kit - so far - is
currently zero, but it seems easy enough, considering that I know when I
start that -1- the system is empty and -2- it doesn't take very much
refrigerant for the AC to work satisfactorily for me.

The evidence to me for #2 above is that the AC works adequately right up
until the time that it is virtually completely empty.

If I were going to charge it, I might just put in a can or less than a
pound. Maybe 2 cans, a bit over a pound and a half. If he were going
to charge it, he would fill it.

I don't know exactly from him how 'bad' the evaporator R&R labor costs
would be, but my reading of the description in the Chilcott manual
sounds pretty extensive to remove the dash.

 

For what it's worth, a can (12 oz.) of R134 at Auto Zone cost $8.99.

A case of 12 (12 oz.) cans at Sams is $39.

If it goes 6-8 weeks on a addition of R134, get a case at Sams.

 

Yep; that's the direction I'm leaning, except I don't have a Sams and
my WalMart doesn't have that good case deal you describe - I haven't
seen any cases online that cheap . I'm hoping this 6-8 week/charge
business holds up. Such an interval was based on a full charge.

Today the AC function was 'gone'. I added 13 oz from a kit can which
came with a connector and trigger for about $5 more than the same size
can. I also bought a couple of $9 Kragen DuPont Suva 12 oz cans at the
same time. The 13oz charge restored good cooling function; so I'm
going with that for the time being. I suspect that it won't last as
long as a full charge.

If the interval is too short, next time I'll use 2 cans.

 

If it is in fact your evaporator, the time between needs to recharge
will get shorter and shorter to where eventually you'll be charging it
as much as you're driving it - IOW, forget it at that point. The hole
is caused by corrosion, so it starts out as a microscopic pinhole, and
gets bigger day by day. As you can imagine, it doesn't take much of a
hole to drain a few ozs. of refrigerant quickly.

One of my Concordes developed a leak in the evap. I did like you
(recharged as needed), and people on the LH car forums told me that
would only work for a while, and they were right. I replaced it myself
about 3 years ago.

 

How about if I introduce a nanobot with some kind of metallic repair
tools into the system?

It/They would travel thru' the system until they reached the hole's
edges, set up a repair station, bond the necessary repair lattice to the
existing corroded structure, and then fill in the lattice with an
appropriate composite delivered by other nanobots.

I should be able to invent such a 'bot complex by the time Boeing
figures out how to attach the wing to the backordered 787.

:-/

 

As I mentioned earlier, shortcuts usually cause greater damage...

The refrigerant capacity of your system is 28 ounces.
You're planning on charging 12 ounces at a time. (less than half)

Oil is circulated thru the system via the refrigerant charge.
Half the charge, half the oil circulation (actually, less than half
since some is already leaking out).
Shortcut = $450 (new compressor) +labor extra over and above doing the
job properly.

 

That would work!

 

Or you could cornpone it:

Go to wrecking yard, find an old transmission fluid cooler, take home,
clean out with mineral spirits, cut hoses off old evap, clamp hose
ends to cooler, install 12v muffin fan from old computer behind
cooler, mount under dash. Instant remote evap! ;-)

Ted

A/C hoses for your car, cut the inside
ends off hoses, replace with