Date: Mon, 6 Jun 2011 13:09:09 -0400
Reply-To: Ken Wilford <kenwilfy@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Ken Wilford <kenwilfy@COMCAST.NET>
Subject: Re: Do AC hoses HAVE to be replaced on a 134a conversion?
In-Reply-To: <BANLkTik=+XF3eT_gWYmOfzGMXqRpdWvWHQ@mail.gmail.com>
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Gregg and List,
Back when R134a first came out, a big deal was made about replacing all
of the hoses when converting from R12. One of the main reasons was
because the molecule of R134a is smaller than R12 and it would
supposedly leak right through the older version of the hoses. So they
wanted you to replace all of your hoses with what are called "barrier"
hoses which is probably just rubber with smaller holes in it so it is
harder for the smaller molecules to get through. However over time
people found that the old hose material wasn't leaking as engineers that
told them it would. The reason is that the old mineral oil that they
used in the R12 systems would soak into the interior of the old hoses
and this would form a barrier that would resist the R134a molecule
leakage. At least that is the theory and it seems to work in real life.
So the short answer is no. As long as your old hoses are in good shape,
not dry rotted or dying there is no reason to change them when you are
converting to R134a from R12. In fact I have had very good luck over
the years doing nothing whatsoever when converting from R12 to R134a
except for charging the system with R134a until it reaches the proper
pressure for the outside air temperature of that day. If everything
else is good in the system except you are low on refrigerant, you can
just install the adapter fittings that come in your conversion kit, hook
up to the low side fitting with your charging kit, turn on the van and
run the AC system on max and charge away until you reach the proper
pressure for the particular outside air temperature of that day. Many
of the charging kits you get have the proper system pressure printed on
the outside of the can of refrigerant.
I have done this many, many times on my own vehicles and customers
vehicles. You can charge an AC system for less than $30 and it will
usually last a summer. Next spring, charge it again and you are good to
go. Just my experience. Every once and a while you run into a system
that has issues like the compressor is going bad or one of the hoses has
blown but that is the exception rather than the rule.
Just FYI,
Ken Wilford
John 3:16
www.vanagain.com
On 6/6/2011 11:33 AM, Gregg Carlen wrote:
> Hi all,
>
> I really need to get the AC working in my van and don't have the time, so
> I've taken my 90 Westy to a shop in Northern Virginia (Brenner's Automotive
> in Manassas) to have the new condensor installed and the system converted to
> 134a. They have the equipment and supposedly knowledge to do the job (e.g.
> hose fittings fabricated, etc).
>
> One of the things the guy at the shop told me before I brought the van in
> was that the hoses could be re-used if they were in good condition (which
> they are) and the fittings repalced to install the new condensor (the old
> fittings are corroded and shot). This morning, speaking to a different guy
> at the shop, I was told that that the hoses would all have to be replaced to
> convert to 134a (he hadn't looked at them for condition yet).
>
> Question is: Is that really true? Even though the 134a operates at a higher
> pressure, I didn't think there was any components other than the dryer and
> fill valves on the compressor that had be replaced. (plus oil, any leaky
> o-rings and the refridgerant).
>
> I have a new condensor from Bus Depot, new dryer and a 'conversion kit' that
> has all kinds of o-rings (and fill valves too, I think). The assume the new
> condensor has R-12 fittings and the shop could just replace the hose ends
> that connect to the condensor with R-12 fittings as well, right?
>
> Thanks,
> Gregg
>
--
Thanks,
Ken Wilford
John 3:16
www.vanagain.com
Phone: 856-327-4936
Fax: 856-327-2242
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