Date: Tue, 22 Feb 2000 13:44:59 -0800
Reply-To: "Johnson, Darrell" <JohnsonD@SYBRONDENTAL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "Johnson, Darrell" <JohnsonD@SYBRONDENTAL.COM>
Subject: Re: Air Conditioning Experience (long)
Content-Type: text/plain; charset="windows-1252"
Ken and all,
In regards to "(can you say "compressor failure" or "hose explosion?")"
The previous owner converted the A/C system on my Carat to 134a. Seems to
be ok so far- kids in the back complain of being too cold. Am I looking at
a disaster waiting to happen?
Is there a good round of preventative maintenance that can prevent my 134a
A/C system from acting like the reactor in a Russian sub? Should I convert
"back" to this Freeze 12 system?
No offence intended to any Vanagon-driving Russian naval officers,
Darrell Johnson
'90 Vanagon Carat
Mission Viejo, CA
-----Original Message-----
From: KENWILFY@AOL.COM [mailto:KENWILFY@AOL.COM]
Sent: Tuesday, February 22, 2000 6:46 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Air Conditioning Experience (long)
Glenn, I did quite a few R-12 to R-134a conversions on Vanagons last summer
(both styles of AC: the older 83-86 style and the newer 86-91 style). There
are several schools of thought on just how crazy to go with a conversion
with
some folks replacing everything in the system except the evaporator and
condensor (this was the original recommendation from the EPA literature I
have read) while others try to just put the R-134a in the system and hope
for
the best. Most AC shops tend to land somewhere in the middle.
Here is what I do:
Replace all o-rings.
Flush out all old mineral oil with A/C flush
Replace expansion valve (most of the time these are kinda crappy looking
inside)
Replace reciever/dryer
Replace fittings and put on new stickers
Replace oil with Ester oil
Pull a hard vaccuum on the system for at least 30 mins.
Recharge the system and check for leaks.
To do this right it takes about 6-8 hours.
Results:
On earlier Vanagons (83-86.5) the system gets nice and very cool, but the
real problem seems to lie in the fact that the blower motors in the
evaporator housing can't move enough of the cool air into the van's
interior.
I have been thinking of adding another fan, and perhaps this summer I will
try this.
On later Vanagons (86.5-91) the blower fans move the air sufficiently to
cool
down the entire van with no problem. On a passenger van this works very
well. On a Westfalia is is OK because the air has to be pushed up to the
front of the van by the evaporator housing that is over the rear seat. It
will cool the van, but the folks in the back tend to get frozen if the folks
in the front are cool. I have thought about tapping a couple small air
ducts
into the evaporator housing and connecting this to the air ducts that run
above the sink/sliding door on either side of the later model campers. This
would allow you to put a vent right above the head of the driver and
passenger and would probably be a big help.
R134a vs R12. There is really no comparison here. The R-134a just doesn't
cool as well and puts more of a strain on the system as it operates at
higher
pressures (can you say "compressor failure" or "hose explosion?") I have
found a third alternative (I will now don my fire proof plaid
undergarments).
I use a refrigerant called Freeze-12. It is made by a Johnsons which is a
company that has been in the AC field for a long time and has a good
reputation. Check out http://www.airconditioning.com or
http://www.technicalchemical.com/freon.htm for more info on all of the
alternative refrigerants out there. Most of the alternatives use some sort
of propane or butane (can you say "Kaboom"?). Freeze-12 doesn't and that is
what initially turned me on to it. It is a blend of R-134a and another
refrigerant that makes the R-134a work at a lower pressure (making it cool
better and not trash out your aging system). I have used it with great
success this past summer on the following vehicles:
86 Jetta TD (dropped in replaced R-12) worked great/real cold all summer.
86 Dodge 16 passenger van (dropped in replaced R12) worked great until
already leaking hoses leaked it out. Got us through the summer.
87 Wolfsburg Vanagon (customer)- (converted over to ester oil and all new
seals/dryer) worked well all summer.
91 Carat Vanagon (mine)- (converted over to ester oil and all new seals and
dryer) worked great all summer. Made my normally hot Maroon Vanagon a
pleasure to drive in the hottest weather (105 F is usually the hottest we
get
here in S. NJ).
The other nice thing is that you only add 90% of the amount of R-12. I
usually just add it until pressures look right for R-12 at that ambient
temperature and it works great.
You do need a licence to buy Freeze-12 (see http://www.epatest.com/ to get
yours!) but I have heard that within the next year you will need a licence
to
buy R-134a too, plus you can't really do a good conversion without some shop
tools (vacuum pump at least and these aren't cheap) so it is probably best
to
let a shop do the conversion just insist on them using the Freeze-12 stuff
(they will thank you later when they see how good it works). Freeze-12 is
slightly more expensive per can than R-134a but not much (I think it was
around $7 a can this last summer).
So I hope this answers most A/C questions. If you have any other questions
feel free to email me.
Thanks,
Ken Wilford (certifiable A/C Tech :)
http://www.vanagain.com
John 3:16
Office (856)-765-1583
Shop (856)-327-0027
Fax (856)-327-2242
