'71 AC refrigerant

[Bwmurph]

I have a '71 Coupe with A/C and lately it hasn't been as cold as I remember it being last year. I have some R-134a refrigerant left over form charging a friends car and I'm wondering if I can use it in the '71.

Is there any way to tell what type of refrigerant is in the system now ?
Can you mix two different types of refrigerant ?

I've oly had the car a few years and the paperwork that came with it references charging the A/C several years ago but doesn't say what type of refrigerant was used.

Any help would be appreciated,

Bernie O.

 

[LLC5]

I have a '71 Coupe with A/C and lately it hasn't been as cold as I remember it being last year. I have some R-134a refrigerant left over form charging a friends car and I'm wondering if I can use it in the '71.

Is there any way to tell what type of refrigerant is in the system now ?
Can you mix two different types of refrigerant ?

I've oly had the car a few years and the paperwork that came with it references charging the A/C several years ago but doesn't say what type of refrigerant was used.

Any help would be appreciated,

Bernie O.

Your vehicle originally came with R-12 in 1971. It may have been converted to R-134A, but do not guess as R134A takes a different oil than R-12 and you should not mix the two. Before adding any freon you need to know exactly what is in it now. Good luck with it.

 

[TimAT]

Your vehicle originally came with R-12 in 1971. It may have been converted to R-134A, but do not guess as R134A takes a different oil than R-12 and you should not mix the two. Before adding any freon you need to know exactly what is in it now. Good luck with it.

what he said. Unless someone did some bubba engineering, the fittings for R-134 are much larger than the old R-12 fittings. It is possible to install the large fittings, charge the sytem, then remove them so it looks like it's still got R-12 in it. Kind of one of those things you really want to know before you drop some large cash on broken parts that were good a short while ago.

 

[Bwmurph]

Your vehicle originally came with R-12 in 1971. It may have been converted to R-134A, but do not guess as R134A takes a different oil than R-12 and you should not mix the two. Before adding any freon you need to know exactly what is in it now. Good luck with it.

LLC5

Thanks for the reply !

Unfortunately I have no records on what refrigerant is currently in the system.

Is there any way to tell what is in there now or do I just have to evacuate the whole system and start over ?

How much of a PI TA is that ?

Thanks again ,

Bernie O

 

[LLC5]

LLC5

Thanks for the reply !

Unfortunately I have no records on what refrigerant is currently in the system.

Is there any way to tell what is in there now or do I just have to evacuate the whole system and start over ?

How much of a PI TA is that ?

Thanks again ,

Bernie O

If you do not know for sure what is in your system, then you need to start with evacuation and a recharge which will mean using R134A. Depending on your system you may need a new compressor and hoses and "O" rings, so I would strongly advise taking the vehicle to an automotive A/C specialist that is famialiar with older vehicles. This is one area that you don't want to get wrong. Good luck with it.

 

[shark454]

The two refrigerant oils in question ARE INCOMPATABLE. Damage will occur (compressor total failure) if the correct oil is not used with the correct freon.
Evacuation is not enough. You need to COMPLETELY remove the old oil. Clean the system compontnts and lines out before thinking of recharging with different freon.

If you are not sure, have a pro look at it.

Good luck.

 

[TimAT]

The conversion kits have fittings that screw on to the originals so the couplings on the A/C hoses will fit. That might be a place to start. If the caps screw on and have no ring like a quick coupling then it's probably still R-12. No guarantees as I said above. The fittings for 134 still screw on usually, but they are way bigger- nearly 1/2". The R-12 fittings are 1/4 or thereabouts.

 

[Bwmurph]

Thanks for all the replies / help guys. Sounds like I need to take it to someone who knows what they're doing to get this straightened out. Also doesn't sound like it's going to be a cheap fix; good thing these people I work for are giving me all the hours I can stand and then some !

Thanks again,

Bernie O.

 

[TimAT]

On the chance this might save you some $$ for diagnostics, here is a link to what R-134 fittings look like.
134a CONVERSION FITTINGS

If your fittings look like these, then you can get a recharge kit at your local auto parts. If they don't, then the choices start.
Many schools of thought on how to get the best possible performance from the A/C with 134. One is to just dump all the old oil, replace the orifice with a blue one, replace all the o-rings, evacuate and charge. Next is to do the above, plus replace the dryer. Last one is to replace all that, and install a parallel flow condenser. There are other options too, but those appear to be the most common.
Overall, the biggest thing is really flush the system well, add the correct amount of the correct oil, and the correct amount of 134.
Let us know how you decide and how well it works.

 

[bagger]

It's been several years back but I converted mine from R-12 to 134A. Had to change out the compressor and I believe it was the dryer also that had to be changed. It was a $800 conversion but it works well. Good Luck.

 

[krscholz]

Don't Mix What You Don't Have To.

Why mix the two when R-12 is still available from many repair shops. Its about $80 a pound.

 

[Bwmurph]

Sorry to skip out on this thread for the past month or so - been out of town, out of country for the the past month.

Anyway, thanks for all the good advice - if I ever get home again I'll check it out to see jsut what I have in the system and will go fomr there. I think it may still have the R-12 but I need to make sure.

Thanks again for all your help !

Bernie O.

 

[73shark]

Might check w/ a good A/C shop to see if their leak detector sniffers can tell the difference between R12 and R134a.

If it has been converted correctly, it will still not be as cold as R12. The OEM system was marginal at best.