Welcome to the Corvette Forums at the Corvette Action Center!

R134 retrofit

jbonifas

Well-known member
Joined
Feb 9, 2001
Messages
94
Location
Shreveport, LA
Corvette
1981 silver/blue: two tone
I ordered a conversion kit from Ecklers. In the kit I received a rebuilt compresser, a drier, an evaporator orifice and oil, seals, fittings, adapters. My quesion is, where do I start? I know my old compresser was bad and there is no freon or pressure in the system. Do I just remove the old compresser, drier and change out seals and fittings? Where does the oil go? and do I need to flush or clean out anything else.
Please help, it is getting hot in Louisiana.
Jeff
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
Sounds like you are on track.

Remove the old stuff. Get a good filter on your air compressor, and blow all the old oil you can out of the evaporator. You can put some denatured alcohol down in the evap, can flush it out as well as the condensor. Let it dry out before putting back together.

Lubricate all the new orings with plenty of the Ester oil (that should be what they sent you). Put the lines back on, put the new compressor on, and discharge the system for at least 45 minutes.

If you don't have the tool. First, go buy a gauge set (about $100). Then, go to a used appliance store and buy a compressor from a normal ordinary house hold refridgerator. It has an in and out hard copper line. Have the shop, or you yourself sweat/compression fit a 134A connector on the suck side.

Get fancy if you want and wire a switch in, otherwise, just plug it in to start. Keep is upright at all times. Now, hook your $100 gauge set on to the pump and to the low pressure side of the car. Turn on the pump and open the low side valve on the gauge manifold set. You will see it pump down to a negative vacuum. It will go down to -30. You want to see it move there within about 3 minutes of plugging it all in. If it does not do that, then you have a leak in the system. Go back and tighten/check your oring seals, and connections. After you get it to pump down for 45 minutes, shut the valve off on the gauge, and unplug the pump. Watch it overnight if you can and make sure it stays at -30. If it has crept back up to 0 overnight, then you still have a leak. Keep at it until it holds.

After it holds, you are ready to pump it up. It should take about 2 to 2.5 cans. The first one will shoot in just with the vacuum in the system. Now, get a bucket and fill it with hot tap water. Drop the can in there while filling on the second can, and most if not all will go in the system.

Now, crank up the car, turn on the air, and jumper the low pressure swicth so it stays running. Watch the gauge. You want it to drop around 30-35 psi and hold there. Top off as needed.

Now you are icy cold, and you did it all yourself.
 
B

Big Fish

Guest
Good advice from 69 my way, but the vacuum pump idea won't work unless you "triple evacuate" your system. The old compressor out of a refrigerator would probably not pull 4000 microns even when it was new. Maybe you have a friend that is a A/C or refrigeration tech who might loan you his pump and deep vacuum gauge. You need to hold 700-1000 microns with the pump valved off for a period of at least 5 minutes to assure a leak and moisture free system. Moisture in the system becomes acidic, especially with the high underhood temperatures in a car. Also that esther oil is a real moisture magnet and you should limit the "open" time of the system. I would try purging the coils with nitrogen rather than alcohol, not sure if that alcohol might affect the rubber seals and hoses in the system, plus you need to be certain you got it all out. Be careful with the hot water, the cans could explode if the temp gets over 125 degrees with a full charge. Hydrostatic pressure develops when the can becomes liquid filled from expansion of the refrigerant heated beyond DOT safe limits. :)
 

jbonifas

Well-known member
Joined
Feb 9, 2001
Messages
94
Location
Shreveport, LA
Corvette
1981 silver/blue: two tone
69myway, Thanks a bunch. I am going to have to think about this for a minute. I guess I was assuming a much simpler job, but I can handle it. I will let you know. That was great advice.
Thanks again.
Jeff
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
It is really not that tough. I am glad Big Fish was able to add some more technical details. It sounds like he knows his a/c stuff. Call it blind luck, or whatever, but me and my dad have gotten by for the last 10+ years and done dozens of a/c systems with the same old pump out of a refridgerator. I don't even know what microns are ;help

I will take a picture of the home made pump for giggles and grins. Could it hold up to daily industrial use? No way.

You will have fun with this project. The pay off is huge, and the money savings significant when you do it yourself.

Before you take my advice 100% though, it won't hurt to check with a professional. Big Fish may have some additional insight as you probe deeper into this project.


I will say though, that a/c specialists are an interesting breed. Most that I have run into treat the a/c system like pure rocket science and make it look and appear as if the average fellow has no business even operating the a/c button on the dash. Add to this the EPA regulations on discharging existing freon in the system, and the average shade tree guy really does not have any business messing around with this stuff.

Good luck with the project. Maybe look for a better write up here soon on shade tree a/c work.
 

jbonifas

Well-known member
Joined
Feb 9, 2001
Messages
94
Location
Shreveport, LA
Corvette
1981 silver/blue: two tone
Thanks again. I was wondering if you could use a vacuum pump to evac and pull down the pressure instead of a compresser. Also, the oil is in a bottle, how does it go in, just pour it in the drier?
Jeff
 
J

jsimpson

Guest
A vacuum pump and a compressor are the same thing. One end is a vacuum, the other end is pressurized. Yes, you can and should use an AC vacuum pump if you have one available.
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
You are going to pour the contents of the oil directly into the drier and compressor prior to installing the hoses. It will tell you in the destructions how much the sytems requires.


As we speak, I am waiting to see the results of an a/c system I pumped down last night. I pulled a full 30# for about two hours (this car was open to the atmosphere for a week, and more vacuum, the more moisture that comes out), plus, I shut down the pump, and am letting it sit. If the gauge is on 30 when I go look at it later, then I am good to go. If it is back to ZERO, then I have a leak somewhere.


I will post some pics and info soon on the DIY a/c tools and work.
 
B

Big Fish

Guest
I thought a little insight on deep vacuum might be appropriate here. Water has a vapor pressure (boiling point) at 78 degrees of 25,000 microns (29" of vacuum gauge). At 64 degrees the vapor pressure of water is 15,000 microns or 29.33 inches vacuum gauge. Since refrigerator compressors will not pull a vacuum any lower than 29" vacuum gauge your system would have to be kept above 78 degrees for any moisture removal to occur. If you believe your compressor will pull 30" vacuum it is time to calibrate your gauge because they will not pull that low. 2 additional problems occur: after several uses the oil becomes contaminated with moisture causing even less pumping efficiency, and because they are designed to be cooled by cold suction vapor under normal use they will overheat rather quickly. Manufacturers recommend pulling a vacuum to hold between 500 to 1000 microns with the pump valved off. This will insure a moisture free system. To accomplish this you need a deep vacuum gauge and a deep vacuum pump. I believe that most auto A/C "specialists" have success on a hit and miss basis, and the only thing that save most jobs is fixing the leaks and changing the drier each time the system is serviced. I am not trying to take anything away from anybody by writing this article, but it is my hopes you might realize the importance of having the right equipment to do the job correctly the first time.
 
6

69Crazy

Guest
Book you might use

You might consider purchasing the book: "Air Conditioning Strategies for the '63-'82 Corvette". Corvette Central has it for $19.95 (order number 112004). I am in the process of retrofitting a '69 Roadster with a hybrid factory/aftermarket system. I need a source for one of the Sanyo 134a compressors. I have seen some really spiffy polished ones that look great! Also, if anyone has any parts for '68 to '72 Corvette A/C systems, I would appreciate hearing from you. I still need:

Side Shroud Vacuum Control
Plenum Panels
Under Dash Brace Rods (don't know for sure if they differ from non-A/C cars)
Center Dash Wiper-Switch Bezel

If someone was removing A/C from their cars for performance, I would have the non-A/C parts to exchange with you.

;help
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
Just call me receiver dryer, because I am soaking up this information like the dryer soaks up moisture.

Now I know what you are talking about, less the technical linguo. That micron and boiling point stuff is pretty cool.

Well, I have used three different gauge sets over the years on this same pump and never had a problem going to -30 (unless my system had a leak). The set I have now (actually belongs to my dad) is a very nice one. The pump has a saftey cut out switch to keep it from overheating. It does get hot, but we have let it run for hours on end before with no problems. We always cap off the ends when not in use to keep the moisture out.

I would also say that most the time we do a/c work the outside temp is at least 85 degrees, so I don't know if that helps in the efficiency.

We also have a large wheeled pump that uses a large electric motor on a belt drive to a pump hooked to a manifold for doing a/c work. It is ancient, and I don't even knowwhere my dad got it. It must have moisture saturation, etc. because it works no where near as fast as the little pump.

I do calibrate my gauge to the zero mark as needed, but I can't verify that it is perfect zero.
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
Here is a pic of the battle worn pump. Man, this thing is awesome and has saved me litterly thousands of dollars over the years being able to do my own a/c work.

I am sure there is no way in the world this thing would last if in service every day. Kind of like many of my hand tools. I have dozens and dozens of wrenches made in Taiwan, China, etc. etc, that would never serve full duty if in the hands of a flat rate mechanic day in and day out. However, for me, and weekend warrior escapades, they work like a charm.

For many years we did not have a switch on this thing, and would just plug/unplug it for power. That was no good, so I wired up a quick switch on the top with an old one I took out of my house.

The fittings get tricky. We started using it when cars were all R12, so it has R12 fittings soldered on the ends. Now, we have an adapter to the gauge set that allows a R12 hose to go from the manifold to the pump, then the manifold and gauge set is all R134 on to the car. When I am ready to charge, I shut off the valve, change the fitting on the manifold and pump in th e134.


I spent $1 on the fitting to allow dual duty, and save the trouble of putting permanent R134 ends on the pump.
 

Jack

Well-known member
Joined
Dec 27, 2000
Messages
1,825
Location
Florence, SC (Timmonsville SC)
Corvette
71 War Bonnet Yellow VERT 71 BH Blue CPE (SOLD)
/ 69 Crazy ... I need a source for one of the Sanyo 134a compressors.
69 Crazy:
Perhaps you are referring to the Sanden compressors (they are smaller, aluminum high quality units oft-found on asian cars) ... perhaps not ... if seeking Sanden, check this:

Rebuilt Sanden SD508 w/clutch $150
Rebuilt Sanden SD508 (polybelt) w/clutch $160
New Sanden SD510new w/clutch $200

Sample prices from recent ad from Carolinas Auto Supply House, INC at 2135 Tipton Drive in Charlotte NC 28206 ... phone 1-800-439-4070 ... fax 1-800-377-7016. You'll need a tax number (legit or otherwise) ... CASH is one of largest ac & radiator & sheetmetal warehouses in the region. Virtually nothing vette-specific ... lotsa underhood parts though. GREAT resource, though CASH offers no tech help for customs/swaps ... ya gotta know yer pn's or originally intended applications. I've been buying from CASH for 25 years ... satisfied.
JACK:gap
 
6

69Crazy

Guest
Thanks

I understand that the Sanyo compressors, although similar to Sanden, are not as good. Thanks for the lead.....I am really hoping to have A/C for the cross-country trip to the Sharkfest....nothing like the great plains in August if you don't have some cooling.

Louie
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Parts/Accessories:

Vetteskins

Advertise with the Corvette Action Center!

Double Your Chances!

Partners

Top Bottom