Hello,

Today I just pulled the engine from my car and knowing I am a car noobie ( being a 16 year old girl with her first car) wondered what should automatically should be changed or checked with the A/C. The freon (spelling?) was not there, but this is believed to be so for about the past 10 years. Would I be able to put the freon in by myself, or would I have a mechanic do it? Also, what precautions must be taken to put freon back in, assuming this is the only thing that caused the A/C to not work. If the freon was not the only thing wrong with the A/C what would be needed to be replaced?

Oh, and one more thing: Where can I find New Old Stock parts?

Thank you so much!
Ashley

Well, the freon got out through somewhere, so you're probably going to have to find a leak. You can do this yourself, but the first thing you need to do is go buy a book on auto air conditioning systems and read it. The leak is most likely a hose, an o-ring at a fitting or a compressor seal. Once the freon has been lost, a new drier (which is relatively inexpensive) needs to be installed and the system needs to be evacuated (vacuumed down). The next question is R12 (VERY expensive) or retrofit to R134 which will work fine, but not cool quite as well, particularly at low speed.

A/C work can be very expensive to have done, but there is a fair amount that you would need to school yourself up in to do it yourself, not to mention a set of manifold gauges (about $50), but it can be done with only a charge hose) and a vacuum pump (big $$$, befriend a mechanic who has one )

Good Luck!
D/W

Oh yeah, Hemmings Motor News and ebay are good places to find NOS parts... Get ready to pay BIG $$$, particularly on ebay...

_________________

If it ain't broke, fix it!

If you'd stop bidding against me, I wouldn't have to pay so much!!!

J/K

Mitch

If we'd all employ a bit of sanity and restraint in our bidding, it wouldn't be so bad...

D/W

_________________

If it ain't broke, fix it!

You are 16 and pulling Slant Six engines out of cars? Wow! I suspect your message mailbox will contain a few marriage proposals soon!

The A/C system should be checked for leaks, and these repaired. Then the oil in the system should be changed, a new drier installed. I would also install a new expansion valve, as there is no way to test it without the system running. The fittings need to be changed to quick connects. Then evacuate the system, with a vacumm pump, and recharge with R-134a. A/C on the older cars is not complex, but does require some special equipment. I am in Florida, if you are near me I could help you.
PS do not install the new drier, untill ready to evacuate and charge.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

you can get a retrofit kit at autozone or walmart for $35, has the adaptors for the old kind, on that topic, i am planning on putting the ac back on my 67, it sat for 9+ years in a barn, when we (actually the guy we hired to get it running last year(before this years motor swap))took the air off it had a bit of a charge in it, so it should hold a charge right? planning on buying the aforementioned retrofit kit, same company made the 134 kit i got for my newer car, got a gauge and lots of adaptors, plus 3 cans of 134/oil havent looked at it real close yet, any input? nice to have another younger slanter, tried to convert my friends to mopar, with limited success....

Andy'sGT
The biggest problem doing A/C work, by a non pro, is the lack of proper tools and equipment. The A/C systems on older cars is really very simple. To do a proper retrofit, it is neccessary to remove as much mineral oil as possible, add the "proper" amount of PAG oil. Replace the drier, (the old r-12 drier is not compatible with 134a). If the system has been empty, and inoperable for awhile, change the expansion valve, in case it is stuck closed. Also some Mopars use an EPR valve in the inlet of the compressor. If the vehicle has one of these, the car will not cool as well using 134a. Requires some additional modifications. It is necessary to remove the air and moisture from the system, with a vacumm pump. Most non pros, do not have gauges, or vacumm pump, and they are not an option, they are necessary. When charging the system, you must watch the high side pressure. The retro fit kits do not give you a high side gauge. Do not charge to a clear sight glass, as is done with r-12. A clear sight glass will be over charged. Do not use compressed air to blow through the system, while it is opened. It will introduce moisture into the system, which you don't want.
Feel free to ask specifec questions, I will try to answer them.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Charlie S,
I need info on AC retrofit from R12 to R134. I have a 1976 Valiant. I know and understand the system and do the mechanical repairs myself and have the local AC shop evacuate and recharge it. They will not work on these old systems anymore, they can't even get the parts!

All (or most) of those RV2 compressors use the EPR valve including my system. What other modifications are necessary? Can I use argon or carbon dioxide to blow out the system? (Those gasses are easy to find because they are used in welding) I've heard to use nitrogen but I don't know if I can find that anywhere. I"ve also been told to use POE oil, not PAG by an AC shop and a major AC parts supplier/rebuilder in Texas. (I'm in Minnesota)

Those R134 retrofit kits in the store are a joke. None of them ever mention evacuating the system. They make it sound simple----- just dump in the included oil and charge with R134. No mention of all the other things that are required.

Craig

I agree with you about the kits. They should be illegal, along with A/C leak stop. That is part of the reason A/C work costs so much. If I didn't have to spend $1500 for a refrigerant identifier, or stop leak filters for my recycling machines, I could charge less. But back to your questions. Most A/C shops, including me, use nitrogen. This is available at welding supply stores. I would think CO2 would be OK, don't know about argon. Do you have the RV2 compressor or the Sanden? Are you using the old compressor, or getting a new/rebuilt one? Using the old compressor, with the RV2, you could use either ester or PAG oil. With the Sanden, I would use PAG. If going with new/rebuilt, use what the manufacturer says, to keep the warrente. Don't forget to drain the old oil, from the old compressors, also, and install the correct amount of new oil.
As for the POA valve, the system will work but not get quite as cool as I would like. I remove the poa valve and Get an adjustable thermostat, with a probe, like the mid 80's diplomats, and 5th ave used. Clamp the probe to the metal part of the suction line, and cover that area with insulation. Then connect the clutch wire to the t-stat. Adj the t-stat to shut off the compressor at about 28 PSI. Might have to tweek it a little from there. Most of the A/C rebuilders are in Texas. If it is the one I am thinking of, I stopped using their junk about 8 yrs ago.
PS: I only use NEW compressors, unless a new one is not available. I would rather use a salvage yard compressor, then a rebuilt one.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Hey, Charlie.

I've been flushing my own A/C systems and blowing with compressed air for years with no ill affects that I'm aware of. All of my air conditioning systems blow very cold and last for years and years without problems. I agree about introducing as little moisture to the system as possible, but if you are using a new dryer and you have a water seperator or other type of dryer hooked to your compressed air, it's not going to be that much. Not to mention that boiling off moisture is one main reason for evacuating the system under vacuum. A system that sits discharged for any length of time is going to have moisture. I'm sure that the way you do it is the absolute best, but the average person need not blow out the system with anything other than air, in my opinion.

On the EPR valve, I've only owned one vehicle with one that I can remember, a '75 Scamp, and I've had many A/C equipped Mopars. I think they were more prevalent in the mid-seventies, but I could be mistaken.

D/W

_________________

If it ain't broke, fix it!

Like the man says, "there is the right way, the wrong way, and my way". I am a professional. When someone asks my advice, on doing a job, I will give the info to do it the right way, to the best of my knowledge. I have done A/C repair on my own vehicles, that I would not consider doing for a customer. If it doesn't work, its not a problem. If itdoesn't work for a customer, it is my reputation. Moisture in a A/C system, with refrigerant, forms acid, which eats the system from the inside. So why would you want to introduce more moisture. Ever have moisture come out the end of a "blowgun"?. How about the exhaust of a air tool. Why add that to the system. I don't have the numbers handy, right now, but at 70 degrees, and 29.9 inches of vacuum, it takes over 3 hours to remove 1 cc of water.
On my RV, I did a 1/2 hour retrofit. removed the suction hose, add 6 oz pag oil, pulled a vacuum for 10 min. and recharged the system. That was 3 yrs ago, and it still blows 38 degree duct temp. I would never consider doing a customer vehicle like that.
The easiest way to tell if a Chrysler system has a EPR valve. RV-2 compressor, service fitting on the head of the compressor, service fitting on the metal part of the suction line at the back of the compressor.
The 76 Valiant had EPR valve, 75 Valiant as far as I remember did not. it use a clutch cycling switch. EPR valve was only used with the RV-2 compressor not the Sanden.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

I hear what you are saying. It's good to know there are real professionals out there when there are so many parading as "professional mechanics" that are full of $#!+...

Still, I say for the average homeowner, some good, relatively cool dry compressed air will work fine. It should be pointed out that the longer you run an air compressor and the hotter the air in the tank is, the more moisture it will hold and the harder it will be for your in-line dryer to remove it. So it might be a good idea to start with a nice cool tank full of air. I've found that here where the humidity is very high like it is around Fla, a makeshift "intercooler" can be made to cool compressed air down and render the water seperator/drain leg more effective. Just route the air through an old A/C condenser (ironic, huh?) and place it in front of a fan, or better yet, in a cooler full of ice... Watch the water seperator because it will fill suprisingly quickly... Another trick is to put the compressor (or at least the air intake for it) inside your comfy air conditioned house, where it can draw nice cool, fairly dry air.

And yes, my '75 Scamp (Valiant) definitely had an EPR valve and did not cycle the clutch.

D/W

_________________

If it ain't broke, fix it!

Charlie, I have the RV2 with EPR valve (reread my earlier post ) I was planning to reuse my old compressor. It was working fine 2 years ago, worked fine one day, and nothing the next. When I took it to the AC shop to have the R12 evacuated, he hooked up the hoses and there was little pressure and was told there was no R12 left. I was present the whole time. I don't know what happened from one day to the next. Anyway, I want to swap the engine soon, then fix the AC again. I plan to rebuild the old pump (unless someone has a better idea). I have all new gaskets and seals, valve plates, and pistion/rod assemblies for it. Try to find all those parts today. A guy at SunairUSA in TX sent me all the gaskets and seals for no charge. I couldn't believe it!.
This pump sure pulled hard and very uneven at engine idle speed or very low RPM. It even squeeled (chirped) the belt a bit at times when running slow. I wonder if I don't have a broken reed valve? I'll find out when open it up. What do I use to wash out the compressor crankcase?

Oh, about this local AC/Radiator shop in town. I don't trust them to do any mechanical work on my AC systems. When I first had this system on my 76 Valiant "fixed" by them 12 years ago, the guy decided the sump gasket was leaking and replaced it. Fortunately I was able to stop in during the day when this was happening. He has already reinstalled the compressor on the car and was about to evacuate and recharge. I asked if he put the correct amount of oil in the crankcase. He said no, he was going to add the oil thru the suction test port!!!!! I had to correct him on that and bring him my service manual that showed how to make a dipstick. and he put oil in the crankcase. Some years after this I bought a Dodge truck with AC from a local person who had the AC service at this same place. The AC was working but a few weeks later started spraying oil out of the crankshaft seal when it was running , but no leaks when it was not running. I replaced that seal myself, I found the old seal installed incorrectly, the carbon ring was up against the crankshaft counter weight, and the spring pack was on next and rubbing on the steel plate that fits in the bearing retainer cover. ARGH! How could they mess up that bad? Well, a month after that the inlet reed valves all broke in that AC pump on the truck. (what caused that?) I could find the parts I needed back then so installed a "rebuilt" pump from Apco Air. That pump rattles for the first few minutes after turning it on. What makes that? Anyway, I wanted the condenser flushed of all the reedvalve pieces and all they did was squirt a tiny amount flush from an aresol can and blow through with compressed air (I did not approve of compressed air, it's full of water as we all know.) Now I only let them evacuate and recharge while under my supervision. (got an extra vacuum pump? then I can do it myself)

What is this Sanden compressor? Where do I get brackets to mount it? Will it fit the C-171 brackets from a Volaré ?????
I do have R-12 for my systems, but am thinking about switching to R-134 while it's all apart. I can sell the R-12 and get a lot of money for it.

1975-76 RV2 systems all use an EPR valve according to my factory service manuals. My 1973 service manuals shows some systems with a cycling clutch and a temperature sensor mounted on the evaporator box with a probe going into the evaporator core. I do not have a 1974 manual to look what those systems used.

What do I use to flush the AC system and hoses? Sunair will sell me 4 gallons of POE flush stuff and a flushing tool for $50 including shipping.

Oh I'd better quit now. I have more to tell, perhaps in a few days.

Bye,
Craig

D/W

_________________

If it ain't broke, fix it!