Need checklist to convert A/C to R134a

[Dino]

This is something I want to do asap, it gets way to hot and mucky here to drive without a/c!

I have the original system under the hood minus the condensor.  The guy who sold me the car had left it with his parents far far away.  He emailed me a while back saying it's at his house and I can pick it up whenever, but he doubts if it's original to the Charger.  As long as it fits it should be okay right?  If not, which is a good one to get?

I bought a new dryer T33317 but that's it.  What else do I need?  New O-rings?  Esther oil?  How about new hoses?  Where do I get those barrier hoses?

I've never worked on an A/C system before and would like to know where to start.  I do not intend to charge the system myself but I would like to get it up to the point where I can drive the car to a garage and have it tested and filled.

Also how do I test the compressor to make sure it works?  I do intend to use the original as I love the look of it, I do not want to go with aftermarket parts here unless I really have no choice.

[Nacho-RT74]

-Dryer with propper silica gel

-Green O rings able to propperly seal the smaller R134 molecules

-Theory says need to change the hoses for a newer more sealed kind due the smaller molecules of the R134, however, on a still good conditions old stock hoses being already seasoned by the years of use should hold the newer R134. I did it without problems, untill hoses break, then changed hoses

-Expansion valve propperly adjusted for the R134 pressure... you can get one new OR readjust the old one. ( I have used the original one without adjust and works nice too )

-Theory says will need to remove the EPR valve from rear outlet of Compressor, and install a thermostat switch tied to the AC lines close to the firewall to cut off the power to compressor by temp ( EPR valve cuts the gas circulation by pressure ) HOWEVER I have run the R134 gas still with EPR valve mounte without problems ( just a light freezing around compressor rear line )... then when refreshing all the system, removed the EPR valve, and still working great without anykind of thermostat switch.
This changes makes to save the gas from freezing inside the line, but living on a tropical country ask me WHEN will the AC gas will freeze ? LOL

-Of course clean the system and replace for the propper oil

JUST A NOTE:

Classic auto air and shops like that charges DOUBLE for parts what regular auto parts stores sells... IE expansion valves and dryers. For a while they charge around $45 for the Expansion valve to R134, Clearly auto parts charged $18 for the same part... same diff about the drier... Parts I got are FOUR SEASON brand, which are OEM. They are coded on PN for R134 or R12, just can't recall the PN codes. I posted a thread about that long time ago

test the compressor:... spin the clutch and will be able to feel and heard the air coming in and out from the front outlet

[Dino]

Thanks Nacho!  That's some good info.

I have the drier, paid less than $20 for it at advance auto parts.  The problem I have right now is that I'm not sure what else is missing as I don't have anything to compare to.  I'm not sure I have the expansion valve either but I see rockauto sells the four seasons one for $16.48. 
All I have right now is these two pictures so maybe you guys can tell what else is missing.

I can't seem to find the green o rings at rockauto and four seasons has tons of different ones.  How many do I need and which ones?

[Nacho-RT74]

dunno, I went to a local AC parts store and found everyone using the black ones as samples. Have no idea about diameters and thickness. The only one I couldn't find is the smaller one what fits on a bulb tube at expansion valve... what BTW comes with the new expansion valve unit, so I won't have to worry about anymore

[Nacho-RT74]

Thanks Nacho!  That's some good info.

I have the drier, paid less than $20 for it at advance auto parts.

and CAA charges around $45 too for that LOL

[Rolling_Thunder]

looks like you're missing the drier and expansion valve...    There should be a steel hard line that travels along the passenger side inner fender top to the condenser...    if it's not there you're missing that too. 

[Dino]

Yep drier and expansion valve are mia.  I have a new drier and will order the expasnion valve from rockauto. 

Hmm..I don't think I have the line going to the condensor.  There's one running over the drivers side inner fender, next to the fender tag but none on the passenger side I can recall.

If you look at the pictures you can see a line end at the orange box, I'm guessing that's where the hard line connects to and ends up at the condensor.  I can hope that the po has it attached to the condensor but I really doubt it, he would have mentioned it.  Oh boy...that'll be a fun one to find...

EDIT:  Found another picture that shows what could be that hard line, if it is then it's simply disconnected from the other end.  Cropped it for a better look.  What do you think?

[440]

Are you keeping the chevy treatment ?

I need to also start finding A/C stuff firewall forward. Hate to think how much it all costs.

[Dino]

Are you keeping the chevy treatment ?

I need to also start finding A/C stuff firewall forward. Hate to think how much it all costs.

  No I'm not keeping the Chevy treatment.  Since I want to work on modifying the steering pump and fixing the header leak I may go ahead and do all the work I can do under the hood in one go.  I'll have to match up the paint as best as I can and will need to do some masking as I really do not intend to pull the engine at this point.  This cannot turn into a long term project.  I can have the car immobilized for a week or two but that's about it.

I also need to swap the carb, install front disc brakes, and I want to get valve covers to match the air filer cover.  I think that if I pull as much as I can, disconnect the headlight wiring (and do the relay mod while I'm at it), pull all the wiring back towards the firewall, I should be able to clean everything up nicely and repaint engine and engine compartment. 

Yeah the a/c stuff is a bit pricey if you have to start from scratch.

[John_Kunkel]

I totally disagree with the notion that old "conditioned" hoses are OK with R134; as stated, the R134 molecule is smaller than R12, it will leak from places that R12 won't and the old hoses probably leak some R12 now.

A full-service A/C shop can install your existing end fittings on modern barrier hose.

[A383Wing]

we have converted R12 to R134a without changing hoses....so far no issues

Now...just be aware that R134a will not cool as well as the older R12...the amount of charge will be different, and you have to put the correct amount in along with proper oil charge as well for lubrication

Bryan  (PS: R134a is being phased out as we speak)

[Dino]

I understand the risks with the old hoses, I did it to my '93 German Ford years ago, not knowing of the risk and it worked out fine.  That said I will take this the scientific what if route and take it to an a/c shop to have barrier hoses put on.  I did not know they could use the original fittings, thanks John!

I heard about r134a being phased out years ago but it yet has to happen.  Europe may be there now bt the US doesn't require new cars to have the upgraded system, whatever it is, until 2017.  I'm sure we'll be able to use r134a for quite some time to come.  Nothing ever goes smooth and easy here.

I do recall you only need to fill it up 80% and although r12 is much cooler, it can still get pretty frosty with r134a.  I really don't need it to go below 60 and I'm sure it will regardless.

Thanks for all the comments, this is a daunting task for me.  Let me rephrase that, everything that is not body and paint or interior is daunting for me.

Got the car out of storage today, Rolling_Thunder, the hard line on th ps is there.  The drier goes in between the two lines.  That means I have one hard line on each side.  After I clean out and test the compressor, if I get the expansion valve and take that and the drier to the a/c shop then it should simply be a matter of them replacing the hoses and putting drier and valve in place, topped of with some frosty?

[John_Kunkel]

we have converted R12 to R134a without changing hoses....so far no issues.

As usual, anecdotal experience varies. I just did some work on a 134 conversion using the original '74 hoses and the hoses looked like frying bacon when coated with Leak Tech....the system would go totally flat in 3-4 days.

[Nacho-RT74]

John as I told, everything depends on hose condition... I never had problems or leaks UNTILL actually they broke.

[Rolling_Thunder]

Yes - that is the hardline you are looking for. That hard line connects to the passenger side of the condenser and the opposing side connects to the Dryer. The other side of the dryer connects to that hanging rubber hose on the passenger side close to the firewall. Looks like you're missing the dryer bracket as well. it mounts to the inner fender.

I have seen cars converted to R134a without issue using the older R12 style hose...    however, technically, the R12 hose should not be used with the smaller R134a molecules...     but in the real world I have not seen a converted system have issues.  

[Dino]

Dryer bracket !!  Ahh why didn't I think of that!  Okay what does this thing look like?  I may have it in a box somewhere...

[Rolling_Thunder]

basically it looks like a big coil bracket -  i'll look to see if I can dig my old one out for a picture.

[Dino]

Which o-rings do I need for the compressor?  http://www.rockauto.com/catalog/x,carcode,1078961,pgname,Heat%2B%2526%252338%253B%2BAir%2BConditioning

I do have the expansion valve installed but for $17 I'm not taking a chance, I'm replacing it.

[billschroeder5842]

I did the 134 conversion on mine and yes, it works but not as well. everything on the system is newish.
Anyone with an idea on how to get it icy cold like the r12?
thanks!

[A383Wing]

I did the 134 conversion on mine and yes, it works but not as well. everything on the system is newish.
Anyone with an idea on how to get it icy cold like the r12?
thanks!

either go back to R12, or live with it the way it is....by using R134a in an R12 system, it will never cool as before

Bryan