Its past tomorrow. My next fc I hope keeps working a/c.

 

This is great knowledge I want to recharge my system too, already. I'm searching ebay for that can puncher thingy

 

This is interesting but making my head hurt lol. Lot of heat today.. Good to see you are still around I haven't heard from you in forever!!!

 

So true. I had a "cheapo" R134 conversion on my GTU and on my old Mk III Supra, and you are correct that the A/C is mostly ineffective when you need it the most.

 

Maybe before people run off and install this R152 it might be worth looking at more than flammability - like when it does burn what happens?

http://forums.anandtech.com/showthread.php?t=324811

Flash fire is not the only concern with R-152a. If ignited, R-152a decomposes into hydrogen fluoride which can be deadly toxic to the human body...

Upon contact with moisture, including tissue, hydrogen fluoride immediately converts to hydrofluoric acid, which is highly corrosive and toxic, and requires immediate medical attention.

 

Life got busy, but tomorrow is coming!


You gotta make your own decision, but make it with as many facts as you can. I'm not poo-pooing this statement, however 134a decomposes into exactly the same materials. R12 does as well. And did you know that for most oF the history of R12 use, leak detecters were propane torches with a sniffing tube? When a leak was detected, the flame changed colors! We made hydrofluoric acid on every job...

 

I just read the post on Anandtech, so I need to put a crimp in this right now. The poster claiming that R134a is more flammable than 'Duracool' is simply wrong on every single level. His focus on 'flame point' is meaningless, and this is the BS that is spread around regarding the HC refrigerants.

R134a has a flash-point temperature. So does propane (duracool) and R152a. Flash point temperature has *absolutely nothing* to do with how flammable a gas or liquid is.

R134a is Non FlammableR152a is FlammableDuracool (HC12a, propane/butane blend)

 

I have been using 152a in my 81 since the beginning of summer.
I found some online for around $3.50 a 10 oz can w/o the bitterent, with free shipping if you buy $50. IIRC. I read a lot about it on the AC forums for a while, and when 134a went to $10. a can I made the decision. It works well here in Florida, but I also have installed a larger Parallel flow condenser.
Can't be used with the mineral oil originally used in the system, ester oil is the best choice.
I tried igniting some, no luck.
I have used propane/iso butane that I mixed myself and it worked ok, but I didn't have the better condenser installed. I would probably would have tried that again with the new condenser if it weren't flammable.

 

^

Where did you get the parallel flow condenser?

 

http://www.ackits.com/c/Parallel/Par...+Aluminum.html

I was fortunate to find one that fit the stock shroud well, had to trim the mounting flanges a bit to make it fit. Also put a sheet metal baffle between the condenser and oil cooler so all air has to pass through them and can't circumvent.

 

What did you do about the lines? They all seem to have a rather different mounting system for the lines...

 

I wasn't out to hijack anything, but..

It's not a difficult process. Basically, you'll mock fit the equipment you're making the lines for, and a professional shop will build them for you. The crimping tools are far more expensive than just having the job done once.

In a nut shell, to make the adapter lines, you first need to mount the components you're making lines for into place: the condenser, the drier/accumulator/receiver and the compressor outlet line (make sure it's in the right position).

Buy the fittings,hose, a marker or white-paint marking tool and a roll of plain steel wire. Mount the fittings on the components you're making lines for, taking the time to note the position and orientation. Using the steel wire, cut the wires to length and use the wire (instead of the hose) to figure out the lengths you need. Keep in mind the ferrules add to the length by at least 1" per fitting. Once confident that you've got the right lengths, you can cut your hose to length, making sure that the hose is fully seated in the fitting's ferrule and mark their orientation.

One thing I did find on mine was that I had to use the fitting off the condenser outlet to accumulator/drier/receiver hard line (the one with the refrigerant pressure switch, a new high-low pressure cut-off switch went in on the high-side line). The drier's fittings are set an an odd angle, so using a 90-degree #6 mio doesn't quite work. The odd-ball angle fitting off the hardline is what's required. Though it would need to be soldered to the adapter line and not pretty, it works well.

Expect to pay around $75 for the labor (assuming you're also rebuilding your compressor hoses with barrier hose), about $25 in fittings and $15 in #6 and #8 Goodyear Galaxy barrier hose) . The parallel flow condensers from AMA include universal brackets that you can bend, cut and drill to mount the condenser in place. If you have the original OE condenser, use it as a template and for its rubber isolator hardware. Also, be sure to bend the brackets to provide a 1.5CM spacing between the mounting surface and the attachment points on the new condenser. That'll put the new unit between the oil cooler and radiator with plenty of space in-between.

Don't go with a condenser that's too wide; you need at least three inches to attach the #6 and #8 90-degree fittings. The condenser can not be mounted upside down or sideways. #8 (larger low-side) orients to the top, and the #6 (small high-side) fitting orients to the bottom.

To give you an idea, attached are diagrams for the lines I had made for AMA Condenser part #12-0544C 14H x 21W. Bear in mind that these diagrams have the length measured between the ends of the ferrules, not total hose length. Also, note that the condenser in question is mounted with the passenger side (right) brackets longer than the driver side (left). So, don't go manufacturing these. Mock things up and measure. If you go with a wider condenser, you need to take that into account when making the new lines.

 

Yup, good info There.

Mine is in an 1st gen so it's a little different. I did one car with a condenser that was larger than stock but could still use the same line routing.
My current DD has the the battery relocated to allow the lines to come out the side of the shroud, allowing an even larger condenser.

 

Wow, excellent post, thanks so much for the information Part numbers, diagrams, very useful!

 

Remember to measure twice and cut once. Don't consider my diagrams and handwriting gospel.

I haven't included diagrams of the condenser mounting brackets--I did those on cardboard and didn't get around to scanning them in. But, they're pretty simple. One end is drilled and cut and looks the same as the mounting tabs on the OE condenser. The other end mounts to the condenser using the included hardware. There are two simple 90-degree bends, with the length between bends 1.5cm.

 

is it tomorrow yet?

 

Here is a list of what you need:

1- 3/16x14" adapter for the highside. Ebay or Ackits.com

1- vacuum pump. RENT at Autozone Free for 90 days...

1-side can tap Ackits.com or ebay

1-manifold guage set. Mine has 134a connectors and it has 1/4" hose ends, so I can remove the 134a connectors and use the hoses directly on the 1/4" connectors on the FC

1-` multipak of R152a Refrigerant. Did I mention it was cheap???

 

If your A/C has never worked for you, replace the reciever drier. You will hate life if you don't. Take your old part with you to the parts store and make sure it is right. If your bracket is welded on to the body of the drier, you must have a replacement that is welded if you have the clamp on type, it must be clamp on.

Also, the drier should come with two new orings. Use them.


http://www.autozone.com/autozone/cat...&parentId=63-0


http://www.autozone.com/autozone/par...ier&store=1516


The R12 OEM drier is not made to tolerate synthetic oils which you will need to use with R152a.

LIFE WILL SUCK if you ignore this warning.

 

No PAG None never on any system that has had R12 and mineral oil in it.

http://www.oreillyauto.com/site/c/de...word=ester+oil




Add about 3 oz of oil to the drier before you put the drier on the car. Lube the orings with ester before you assemble.

IF you have removed the compressor, turn it upside down to dump all the mineral oil out. Rotate the shaft both directions to get every possible drop of mineral oil out of the compressor.

Add a couple of oz of ester oil to the compressor on the bench. Rotate the shaft 15-20 times, then dump the oil with the compressor upside down. This is to flush out as much mineral oil as possible. Now add 3 oz of ester to the compressor and remount the compressor in engine bay. This step will assure the longest life of your system. I did this in 2005 on my vert. I have had ZERO trouble with my A/C since then.

Don't attempt to replace any orings unless you have the specific joint apart for another reason. The old orings will not leak if the joints haven't been taken apart! The hoses do not need replaced (unless they have leak). Dont make this process any more difficult than you must.

 

Since you have just replaced the drier we assume the system is empty.

Attach the highside adapter on the driver side near above the exhaust manifold.

Attach the red hose to the highside adapter.

Attach the blue hose to the new drier.

Attach the yellow hose to the Vacuum pump.

Check that both needles on the manifold gauge point to exactly -0- psi with the valves open and the hoses open also. If they do not, unscrew the clear covers and use a small screwdriver to zero both gauges.

Turn on the pump and open BOTH valves on the manifold gauge.

Let the vacuum develop. It must reach 30" on the gauge.

When the vacuum reaches 30", let the pump run for another 10 min, then close both gauge handles, shut off the pump and wait. The vacuum should hold at the exact level for 15-30 min without moving. If it doesn't run again for another 20 min. Try again. If it holds, move on. If it doesn't, you are out of luck and need a repair that is beyond the scope of this thread.

 

With the valves still shut, turn off the vacuum pump and remove the yellow hose.

Attach the side tap to the hose and puncture the can. Aim this away from your eyes, wear eye protection etc etc.

BLEED THE YELLOW HOSE!

At this point, the yellow hose is half filled with air and half with 152a. We cannot have that air in the system. It is non-condensable and will cause all kinds of problems. Air in the system from sloppy or ignorant charging is probably the #1 problem with DIY A/C work.

Very slightly unscrew the manifold end of the yellow hose. Some gas will start to bleed out. You WILL be able to tell when the R152a gets there-it will be cold. Tighten the hose.

You are now ready to charge!

 

Close the red highside valve after you vacuum. When you are charging you are never going to open the valve on the RED-High side!

With the can tap on the bottom of the can you will get liquid into the system. This is what we want initially. The combination of the vacuum and the liquid will allow most of the first can to enter the system.

Start the car, turn on the air conditioning system. We want re-circulation button on. We want low fan. We want the temperature all the way down.

Put a thermometer into the center vent. Temperatures should begin to drop.

The rest of the first can will be drawn into the system. High pressures will be in the 150 range, low pressues will likely be in the 20-30 range. The compressor may cycle on and off periodically.

This is a good sign.

 

When the first can is completely sucked into the car, you will be able to tell. The can will have attained ambient temperature and will have no cold spots.

The compressor should be cycling. Off at about 22 psi and back on at aboutj 40-45psi. Try to catch the pressure at that low pressure, then close the blue valve.

Remove the first can from the side-tap. Tap another can. If you do this with no delay, there is no need to re-bleed the hose.

Open the valve and allow the entire second can to enter the system. You may have to have a helper hold the engine speed in the 2000-2500 rpm range.

You should only add gas, not liquid with the second can. As you do this, the can will get very very cold and the gas flow will slow. Use a pitcher of hot water to add heat and keep the refrigerant flowing.

When the second can is in the system, you will be fully charged with R152a. A full charge is around 20-22 oz. This is because of molecular weights being different.

You should be able to get 40* air at the center vent at low fan speeds at idle. At 2500 rpm, you should be able to get 40-45*air at the center vent. All temps measure with air on recirulate.

 

Wait until the pressure is at it's lowest, then remove the low side hose. I use two hands. One hand keeps the hose pressed and sealed against the fitting while the other hand unscrews the threads. When it is completely unscrewed, remove the hose. Put on a service cap! This is very important. Most of these old valves leak a bit. You can fight it and try to find a new valve, or you can put on a cap and seal it up.

Turn off the car, let it cool down before you remove the high-side hose. Spray some cool water on the condenser. Your pressure should be down in the 75psi range before you attempt to remove the high side hose.

Keep the pressure with one hand, unscrew with the other. You are going to get some liquid refrigerant spray out. You can get localized frostbite if you are not careful...

Goggles, eye protection etc!

Put a cap on the high pressure adapter. If you only have one car, leave the adapter on the connector and put a 1/4 cap on the adapter. They are easy to find. 3/16 caps are hard to find in a store, but are easy to find in the salvage yard. Most 84-93 cars in the salvage yard had a 3/16" adapter. Half of those will still be in place.

 

Check for leaks with a spray bottle of soapy water. 3-4oz of Dawn in 16 oz sprayer filled with water will give you an easy way. Spray all the connections that you had apart. If you have leaks, there will be voluminous bubble production. If you used the correct orings on the drier, you should be in fine shape.