240z MSA AC compressor coversion

[JaredL]

I searched around and could not find much information on this setup.

I just got the ac working in my 72 240. It is the dealer installed ac and it basically just doesn't work very well. I have tried two different york compressors both with the same results.

So I saw that MSA sells a COMPRESSOR CONVERSION for 70-73 z's I'm assuming that this to replace the york compressor with a newer rotary style one.

So my question is has anyone used this? Or does anyone know what the compressor is from, and if it is worth it?

I have not replaced my blower motor yet but that is the next step, although I still don't think it will make it work much better.

On a side note, does anyone know the part # for the dealer installed ac belt's? I got a 54" long 1/2" wide v-belt. It seems to be the correct length but it slips from time to time.

[hls30.com]

When you got the AC working did you fully evacuate it first and then charge it properly, or just add some freon/substitute?

Noth that the dealer installed AC was all that great, but it should have the best shot at pleasing you before you start throwing money at the problem.

Will

[JaredL]

I used enviro-safe, I read and heard nothing but great things about this product. My brother used it and acheived about 40 degree temp's out of the vent's while the outside air was about 90.

[sblake01]

A couple of things here. The old York compressor is an R12 compressor. I'm sure that the one MSA sells is a R134A compressor. You'd have to change other components and I still don't think you'd be happy with it. I'm a certified MVAC tech so I have the equipment to proprely service an a/c system. First thing I would do is flush that old york system. If it's been sitting for some time who knows what kind of contaminants are in it. The I would pull a vaccum on the system and see if it holds. If it does, I'd fill it with R414B since that is the only refrigerant that work in an R12 system without modification. At that point, I'd check it for leaks. Generally, if you're going to have any leaks with that kind of system, it will be hoses. They can be replaced. I have done one of those systems before and was able to get it to cool to 42 degrees at the vents. I can get the later factory Z car air (280-280ZX) to cool down to the mid 30s at the vents. Set up properly (no Pep Boys 12 oz cans) and assuming the compressor is in good condition, the york system will cool your car.

[JaredL]

The car has no leaks, that has already been verified.

What would be the proper way to flush the system?

Who sell's r414b?

I am relatively new to ac systems, and recently moved from cape cod and all we ever did there was take the ac out and throw it in the trash, but these 100 degree days are just killing me.

I got the car tinted today, now it just needs the ac at 100% I'm willing to do pretty much whatever it takes. So I really appreciate experienced opinions and proven procedure's.

[sblake01]

IIRC, EnvrioSafe is an R134A replacement. I'll look into that. But if it is you have to be careful using it because R134A and it's replacements run higher head pressures than R12 and its replacements. You'd run the risk of blowing up that old compressor.

[sblake01]

R414B goes by the tradename of 'Hotshot'. You need an EPA 608 or 609 certification to buy it. To properly flush the system you would need a flushing nozzle or a Recovery/Charging system and 6 to 16 ounces of Auto air flush and clean. There are several brands of it on the market. You'd pump it through the system and out into container, close up the system and pull a vaccum on it to remove any excess flush and/or moisture. Like I said, I'm and HVAC tech so I have the equipment. It would probably be better for you to get it done at a shop. One word of note. If you have anything other than R12 or R134a in your system, most shops won't work on them. That is what prompted me to get the training, the certification and the equipment.

[Ed]

Stephen,

I've heard that if you have copper lines the R134a won't work as well as the R12. Have you heard anything like this?

Ed

[sblake01]

Never heard that one, but I haven't worked much with R134a.

[JaredL]

Enviro-safe is a direct r-12 replacement.

Im starting to think I may have over pressurized the system. Does anyone know the volume or pressure the system should be charged to for r-12?

Here is some info on Enviro-safe http://autorefrigerants.com/co00033.htm

[sblake01]

Enviro-safe is a direct r-12 replacement.

Im starting to think I may have over pressurized the system. Does anyone know the volume or pressure the system should be charged to for r-12?

Here is some info on Enviro-safe http://autorefrigerants.com/co00033.htm

According to the chart in your link under technicians information, EnviroSafe is a direct R134a replacement. .33 lb of ES12 is equivalent to l lb of R12 which makes it's density more like R134a than R12. With that in mind, you probably did overcharge it. I would suggest checking with autorefrigerants.com for their recomendations as far as volume and pressure because I am unfamiliar with their product. One other note. They say to charge the low side to no more than 60 psi. That is considersablly higher than what the R12 low side limit is. If your pressures are too high it can not only cause the system to function inefficiently, it can damage components. If you don't have a charging manifold to visually check this with, I would suggest getting a hold of someone who does. I only charge from a cylinder with a manifold. I've always been against the use of those 12 oz cans because you have no real way to read the pressures.

[sblake01]

You know, I just read that post I made last month and noticed that I said lower when I meant to say higher. The line should have read: That is considerably higher than what the R12 low side limit is. I have edited it. I hope no one did any thing based on that post. I like my low side (w/414B) more than 36 at an idle. High side no more than 205. They both drop as engine speed increases to a point.