Re-hashing R134 conversion

I have done the conversion on my car and others.

In my opinion, all of the early "chicken little...the sky is falling" reports of Hell on Earth with the "improper" procedure, the reports are grossly over rated and basically are a really bad over reporting.

All you need to do in a properly functioning system is change from R12 to R134. Period.

I think it is a good idea to change the reciever /drier and switch over to the sankyo rotary compressor.

Other then that everything is fine.

What you will see in the difference between the two systems, R12 and R134, is that is is more difficult to get the temperature to blow out of the registers in the high thirty degree range.

The coolest I've been able to get is about 40 to 42 F out of the registers.

You will also notice that the 134 is a higher pressure system, but that's to be expected because R134 has different properties then the R12.

As FDR once said, "we have nothing to fear but fear itself".

You are going to get different opinions. Mostly from pencil neck engineers who just can read specifications and probably couldn't even install a hub cap themselves personally?

I'm sure they could supervise the heck out of the installing mechanic though?

On stuff like this one really needs to be a "hot rodder" looking for things that actually do work, but on paper don't?

I personally have found that the original Pantera system is on the hefty side and nothing fragile about it.

You can change the condenser but you don't need to. It's just needless expense.

... I'm not a pencil neck engineer ... but you might be physically able to evacuate the R-12 and add R-134a ... but it will not work correctly and will not last long.

R-134A Ac units are physically 30% larger ...which means you need larger coils. The hoses have higher ratings and the seals are of different composition .

How about buy R-12 and just fix the existing system ... that's what I did and my car is ice cold inside in the summer ?

quote:

Originally posted by accobra:
... I'm not a pencil neck engineer ...

...be that as it may...the two seals you need to worry about in the Pantera are the connections at the compressor. All the other connections are European metric versions of JIC male and female threaded hose end fittings.

In fact they may be US JIC or SAE fittings I don't remember. I do have an extra set under the bench in the shop and can check if you make me and I HAVE TO

If you go to the rotary compressor then you don't use those connections. The compressor as I recall will already have -8 and -10 JIC male nipples already on it.

Yes R12 is absolutely the best for this system.

I've been running 134a in R12 systems with no other changes since about 1992 or so.

The only draw back I see, if it is even a drawback is that 40 to 42 degrees F is the coldest I can get it to blow out of the register vs. about 34 degrees for R12.

I think what the answer is in the Pantera is simply that the cabin is so small, if you install the hot water shut off valves, that a 30% larger capacity isn't really needed.

It does exist because of the late model Panteras and it is your money if you want to buy them but I thought the term NEEDED was mentioned in the question

" All you need to do in a properly functioning system is change from R12 to R134. Period."

Not True... the expansion valve is different, the filter drier is different, the seals in the compressor are different, the evap and cond coils should be larger ( but you might get away because a Panter interior is small) the composition of the hoses are different in pressure and material, etc ...

It might work but your not getting max efficiency out fo the system ... I would venture to say ...an entirely new compressor and system might even be less drag off the engine.

Personally I would update the entire system ... my 79 all it needed was gas R-12.

My 2 cents ...

No. That's what you are SUPPOSED TO DO. Here we go. The system just plain works with 134a. Maybe it doesn't know WHAT IT IS SUPPOSED TO DO?

You make a GREAT pencil neck.

Hopefully have not started a "war" !!! Frankly, I am astonished that the hoses are not weeping R134. If it were MY car, I would see if the existing system was functional and bight the bullet for R12. Cheaper than converting.