Date:         Mon, 19 Aug 2019 01:59:13 +0000
Reply-To:     Richard Koerner <rjkinpb@SBCGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Richard Koerner <rjkinpb@SBCGLOBAL.NET>
Subject:      Re: Fixing Vanagon A/C..Hooked up Gauge Set today
In-Reply-To:  <326666079.1425021.1566089996067@mail.yahoo.com>
Content-Type: text/plain; charset=UTF-8

 This was fun.  Purged all lines while hooking up manifold to Vanagon A/C system.  Subaru motor was all nicely warmed up.  Readings at 75 degrees F ambient here on a mild day in San Diego were 29 PSI on the Low Side and 245 PSI on the High Side, this was with A/C on blasting away at full power.  Yes...I think this confirms overcharge.  Again...did a lot of internet research, and am still researching.  These readings were at Subaru motor idle at about 650 RPM.  Some advice recommends revving and holding motor to something like 2000 RPM (with a piece of wood or something) to replicate while going down the road, not sure that advice is good.
My A/C is working good....at mild temperatures.  When I hit that 106 degrees F in Phoenix, my system shut down.  I think this was per design...to prevent damage to compressor.  Indicating overcharge of R-134A refrigerant.  I'm pretty sure of it.....it's all starting to make sense.

If anybody has any advice, I'd sure like to hear.
Rich
San Diego

    On Saturday, August 17, 2019, 6:00:19 PM PDT, Richard Koerner <rjkinpb@SBCGLOBAL.NET> wrote:  
 
 Amazon Prime showed up today with my FAVORCOOL CT-136G set.  Man...I'm impressed!  Everything looks very nice; fittings all work, no burrs on machined parts, nice Quick Setup laminated instructions, hoses look solid, and so does the feel of all the valves.  Gauges were both right at zero mark.

Opening and closing valves....wow, that's an understatement once you start getting into the nitty gritty.  To prevent the novice mistake of introducing air and water vapor into your system by not understanding what is happening at each step seems to be a big one.  In many Youtube videos, purging of the Yellow Line to add refrigerant was often omitted, but that's sorta obvious; but ya know...you also need to purge the red and blue hoses too, only found 1 Youtube video explaining that.  Easy to do, but you've got to have your wits about you while you do all this.  Understanding what is happening inside the manifold when you turn those knobs is key.

I'm thinking of making a Word Document...sort of like a Pilot's checklist...so that nothing is overlooked.
Overall, I'm very pleased with my $55 investment.  But, the next step will be to actually hook things up.  One key point:  how much refrigerant?  Pro-shops might use a big tank of R-134A and use an electronic scale to know exactly how much refrigerant they are adding per the system specs.  The problem here though....my '85 Tintop Vanagon A/C with a 2.2 Subaru engine and compressor is now a "hybrid" of sorts.  I don't know the amount.  And, I've already got stuff in the system, I'm not starting from scratch with an evacuated system (due to the addition of Stop Leak as mentioned previously and the hassles that causes for shops).  So that's where those "tables" come into play I think....ambient temperature and Low and High Side pressures.  As it turns out, only a few ounces can make a difference...at least according to the Youtube videos.  We'll see.
The saga continues.  But I'm glad I bought the gauge set.  I'm also thinking of taking a reading every 2 months or so, plotting a curve, so will be better educated on how things are leaking out; I also learned that 85% of leaks (resulting in bad A/C performance) are at Low and High side Schrader valves, and those can be replace readily.  Fortunately, mine are only 2 years old (when converted from R-12 to R-134A) so most likely are just fine.  Also, since Winter is coming, I don't plan on adding any refrigerant during that time, so that will make it easier for me to plot a leak curve.

Rich
San Diego


-------- Original Message --------
Subject: Fixing Vanagon Air Conditioning...Instrumentation is next step
From: Richard Koerner <rjkinpb@SBCGLOBAL.NET>
Date: Thu, August 15, 2019 7:24 pm
To: vanagon@GERRY.VANAGON.COM

 I took my van into my local professional.  Explained my fear that I had overcharged system.  He went back to his records of 2 years ago, and confirmed the diagnosis back then...that I had several leaks that were fixed (O-rings) but one leak that could not be easily fixed---the Evaporator over the front seats in my 85 Tintop Vanagon.  I explained to him that I had added a Stop-Leak product a year ago; this had helped a great deal performance wise, but over time, the refrigerant gently leaked out.  But now, to evacuate system, he could not use his normal equipment, he would have to use a special pump and some sort of special filters so it wouldn't ruin evacuation stuff; he could do that job, and also put in new R-134A.  Problem is.....estimate was $400.  Ugh. 

He asked me why I thought I had a problem; I explained that latest trip to Phoenix with 106 F temps, my A/C worked for a while, but then seemed to throttle back down.  He hooked up his gauges (at no charge BTW).  According to his gauges, yes, I might be a little high.....but nothing to suggest a radical concern like damage to system, especially Subaru 2.2 motor compressor.  

So....now what to do?
I've looked at a ton of YouTubes; there are some good ones; that explain what is happening with differences on Low Side and High Side pressures, and what they might mean, and how to fine tune.  The one commonality in all of these explanations is to have proper Instrumentation.  

So....I looked into that.  On Amazon primarily.  Typed in "R-134A Gauges".  Man oh man....bewildering with the choices.  My research seems to indicate Harbor Freight stuff is not worth the bother.  But no, I don't need something that I will use 10 times a day to earn my bread and butter.  Learned a LOT about key features to look for....like being able to easily purge air from the Yellow Line (before adding refrigerant) and also to be able to easily decouple fittings.  Overall ease of use and reliability of gauges.  And reliability of connecting seals (Teflon hard plastic vs. soft green Viton O-rings).

I've orderd this one; the company is most probably off-shore, but they've been in the HVAC business 30 years, and it's hot and humid over there, so that's a plus: FAVORCOOL CT-136G 3-Way AC Diagnostic Manifold Gauge Set with Case for Freon Charging, fits R410A, R134A, R22 Refrigerants, Aluminum Body, Sight Glass & 1/2 Acme Fittings, Quick Couplers & Adapters

| | 
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FAVORCOOL CT-136G 3-Way AC Diagnostic M...
 |

Wasn't a huge investment at $55....but now at least I will have some Instrumentation to be able to follow along with my system's performance.  Of course, like all DIY people, I hope it wasn't a waste of money.  As always, any input from you volks is really appreciated and I hope as well this story is of some help for you.  We're all learning, both from our mistakes as well as our successes. 

Trying to make 35 year old stuff operate like new stuff....Dreaming the Impossible Dream.

Rich
San Diego




 On Saturday, August 10, 2019, 7:01:56 PM PDT, Richard Koerner <rjkinpb@sbcglobal.net> wrote: 
 
 Yes, Dennis..my AC professional recommended regular use.  Keeps seals soft and lubricated I guess.
Don't hate me...but I am also intrigued with the Harbor Freight Low and High pressure gauge setup.  About $60, and with a 20% off coupon, it starts looking worthwhile.
When I attempted recharge on my Vanagon R-134A system, all I had was the "low side" information.  Seems to me, that having the extra data of low side and high side pressures while recharging, would be very valuable information.  I watched those guys at my AC shop a couple years ago; yep, they had the gauges for both high and low side pressure right in view.  They also had a big can of R-134A turned upside down and pumping it into the system; I thought that was a No-No.  Freon should be gently introduced into Vanagon system....at least my thoughts from Samba and Internet research. These guys are aware of Vanagons, but also deal with normal cars, so I won't hold that against them.

Yes, for sure, I will have professionals evacuate my system, and recharge to optimal levels.  Next week.  

But....as time goes on, and freon depletes with corresponding depletion of AC performance, I'm trying to figure out what to do.  No, not gonna replace Evaporator Unit...NLA.  Nor hoses.  

Visible Dye, whether via Ultraviolet light or just normal light, should sure help out.  But my expectation would be that it would mostly reveal leaks at O-rings.  And they were all fixed 2 years ago.

So....I want to get my AC system back to Zero.  Get evacuated (to remove any little water molecules) and then refilled to optimal R-134A Freon charges....
I will update the story for all interested.
Rich
San Diego





 On Saturday, August 10, 2019, 6:33:06 PM PDT, Dennis Haynes <d23haynes57@hotmail.com> wrote: 
 
 
One thing that might help would be to add a dye to the system to help find leaks. Working AC is not only just for cooling. It can also be used to help defog windows as it can remove humidity. Most modern cars use the AC as part of the defog operation above freezing. Regular use of the AC will also help to keep a system alive and well.
 
  
 
Good luck
 
Dennis