A/C to R134

[NewTimer]

I guess this would be considered "modified"

 

I am working to refresh my engine bay up and with that came a new pulley kit from march that requires a new style a/c compressor.

 

I looked at the Tech Archives and to convert to r134 on a stock system Rob mention that he changed nothing

Archive

 

But with the new style compressor would this still be the same procedure? I will have condenser and evaporator pressure tested and all old freon flushed. I am replacing the accumulator already.

 

Also with my new compressor it mentions to replace the Orifice tube but I have no idea what that is or where it is located.

 

Thanks for any help.

 

Edit: Using factory evaporator only thing changing from factory system is compressor

[D.E]

to get it working right you need the condensor to be larger to use 134a.The org compressor will not work good also with 134a.I repalced everything on mine from Classic Auto air for use with 134a

[NewTimer]

With the march pulleys my compressor will be on the passenger side so I think I will replace the condenser with the vintage air condenser which has both outlets on the passenger side.

 

But what about the oriface tube? Where is that located?

[Sam (Bones)]

in the inlet to the evaporator

 

if you got a smaller diameter crank pulley....be careful, it can cause cooling problems and alt charging problems, a smaller crank pulley will slow down all the other pulleys too

[NewTimer]

Do our Monte Carlos have the Orifice Tube? everywhere It shows as not listed, and summit stops 1975.

[jim's 70]

The original systems use a POA valve, not an orifice tube. Same function, but much bigger and bulkier. If you look buy the a/c box in the engine compartment, you will see a rectangle block with 2 lines, and has what looks like a disc on top. There is also a capilary tube that is wrapped around one of the tubes and secured with a sticky rubbery mess...I'm sure there is a name for it..but I have no idea lol

[NewTimer]

Yeah after hours of research, I was starting to come that conclusion lol

 

I am just going to update the POA valve. Any tips on that? I am not concerned about the difficulty just what I should be aware of when doing the change.

[jim's 70]

Check with Dan's 70 z20...he had his rebuilt to handle 134 by a company in Florida...I'm sure there are others out there as well as updated non-original looking ones

[monte70car]

Here is what the POA looks like Here is what Classic Auto Air says to do 1966-73 Models with POA Valve

 

The POA Valve is installed on the evaporator, near the firewall. (Click here for a typical photo)

 

Minimum Requirements

 

Change or restore the filter-drier.

Drain the compressor oil and recharge with 134a compatible oil. (PAG or Ester Oil)

Insure that the system is clean and free of contaminants (Depending on component condition, this may be a simple matter of blowing out with compressed air or liquid flushing with an air-conditioning flushing agent)

Replace or restore all rubber hoses with barrier hose.

Install 134a charge port adapters.

Send POA valve in to be calibrated

Charge with 134a between 70-80% of the original R12 charge amount.

Replace any o-rings with 134a compatible.

 

Recommended:

 

Install hi/lo pressure switch

 

HELPFUL HINTS

 

Ignore the sight-glass. A properly charged 134a system will likely show bubbles in the sight-glass.

Typical 134a charge rate will be approximately 70-80% of the factory R12 charge amount.

Any POA Valve issues when converting to 134a? [more]

 

If you are converting to 134a Refrigerant, your POA Valve will need to be recalibrated to by-pass at a different rate than it did with the old R12 Refrigerant.

 

You can send your POA Valve to us and we can test it for you. If it passes a series of tests, we can recondition and recalibrate it for you. If it is a Frigidaire Valve and it fails any of the tests, we can completely rebuild it. See the "What is POA Valve Reconditioning?" and "What is POA Valve Rebuilding?" questions below.

[NewTimer]

Thanks for all the help, I have decided just to go with a new POA, my car will be no where near original so I went with Old Air Products POA updated valve which has the Hi/lo switch already on it. With new O rings as well. (POA Valve)

 

Before I take it apart I will have it flushed and I am changing the condenser with Vintage Air's Kit ( Condenser ) that comes with a new drier. I also already have a new March compressor that will be mounted on the passenger side and hope to have it hooked up with earls braided line and fittings.

[NewTimer]

So I have another solution/problem I need advice on, I have purchased a updated POA valve. And had a plan to use all braided line. The suction fitting that attaches to the rear of the POA valve is a hardline. ( fitting ) I had a plan of using braided line but with the fitting it only allows it to be crimped.

 

Can aeroquip ac line be crimped?

 

If not, I had a plan of just cutting the fitting and having a local shop tig weld an AN fitting to the end. Anyone see this being a problem or something I should address to the shop when doing this?

[footballubet]

I don't think Aeroquip fittings are crimped. I would talk to the shop doing the work and see what they advise.

[NewTimer]

Well I don't see a problem with this, basically doing the same thing this guy did to his fuel pump. ( 4th post down )

 

Edit: Has any one changed the expansion valve?

[dcvice1967]

I'm not sure this will help you but I found out after we had our newly installed vintage air system filled with 134a. It appears both r414 and another freon replacement called Freezone are suppose to be a direct replacement for r12 and work just as good.

[LostnFound]

There's one sold up here made by Red Tek and is called 12A. It is a direct replacement for R12.

[Rooster]

I have some R-12 if anyone is looking.