A/C change from R12 to R134a

[jthomas68]

What exactly is involved in the change?My system worked 2 summers ago when i got it,but it`s now completely empty.There is a large leak in the dryer/accumulator,so that is being changed.I figure it would be a good time to do the upgrade.Does anyone have the steps of what i need to change?Also,is there any way to test the system to make sure the compressor any everything else works?It won`t turn on with no fliud.

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Jeremy Thomas
Juiced 91+
SHO Pic Of The Week:

 

[sdpatt]

I had my system converted last summer on a long road trip by a Ford dealership. They replaced all of the O-rings, accumulator/dryer, most of the lines in the engine compartment (due to an earlier battery acid leak) and then flushed out all of the old oil. The oil must be cleaned out since the R12 and R134a oils are not compatible. The compressor should be okay. The heat transfer capacity of the R134a is less than the R12 so the ultimate cooling capacity is a bit less.

The compressor clutch won't engage unless there is a minimum pressure in the system. The cycling switch on the top of the accumulator/dryer is responsible for this. You can pull the plug on this switch and jumper the terminals to engage the compressor, but remember that the switch serves a protective function for the compressor.


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Scott

1991, 254K miles, glass hood, police grill, SVO shifter, Catz fogs,
K&N, 73mm MAF, Superchip, PP Y-pipe, Borla cat-back, 190 lph pump
Eibach/Tokico/polyurethane, SHO Shop front & rear strut braces,
16x7.5" Moda R1, 225/55ZR16 Bridgestone RE730, -1 deg camber x 4,
6 disc CD, Class II hitch, Silver award at SHOklahoma Car Show

 

[Rob94]

Yeah, what he said......Scott, have you found the cycling switch to be a fairly high failure item.......I ask because I have had to change mine 3 times in 4 yrs....each time, a new switch solves my problem of the compressor clutch not engaging. I also think it is time to replace the compressor clutch, as it has been making a lot of noise lately. I checked the refrigerant charge, and it is at the proper psi. It is just engages rough, and then disengages kind of sloppy. Is it difficult to replace the clutch???

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Rob
White 94MTX
K&N Filter otherwise stock

 

[sdpatt]

I have seen posts regarding the replacement of the compressor clutch. You may just want to search on the key words. Mine has only been replaced with a new compressor at around 200,000 miles. I can't imagine the clutches failing too often. Have you had a history of refrigerant leaks and rapid cycling of the compressor clutch? That would cause unusually rapid wear the clutch.

Scott

[This message has been edited by sdpatt (edited 01-19-2002).]

 

[jthomas68]

I have the same battery leak,i believe that`s how the drier went.It blows out like there is a huge hole.I was having it tested for leaks,but it blew out so bad that i couldn`t get any in the system to check.Like i said,it worked when i got the car in August,but the following summer i tried and got nothing.I figure the dealer gave it a quick charge before selling,it leaked out over the winter.

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Jeremy Thomas
Juiced 91+
SHO Pic Of The Week:

 

[myshonuff]

i did the conversion on my 93atx all that was done was change the drier evacuate the system add new oil and charge to date no problem and i still have the original compressor its been 3 years now.

 

[Hambony]

what exactly was the cost at the dealership? I am debating whether to just recharge my system or have it switched over in for the long haul.

 

[jthomas68]

FWIW,the a/c unit is a closed system.If it EVER needs to be charged,there is a leak somewhere.

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Jeremy Thomas
Juiced 91+
SHO Pic Of The Week:

 

[jbserra]

I have the same question as Hambony. What does it cost to have the dealer upgrade a leaky a/c system to the new version?

 

[fricker66]

Last summer, one of my friends had Ford install a new compressor, flush the system and switch over to R-134a for a cost of $1100. My guess would be you could knock off several hundred if you are keeping the compressor.

I'll be faced with the same issue this summer. I burned up a clutch last summer as a result of rapid cycling like Scott mentioned. To finish out the summer, I had a new clutch installed and charged the system for $270. (Clutch alone was about $180) This car's a/c system has leaked since new, nobody claims to be able to find the leak even with tracing dyes added. Any thoughts on how to 'permanently' fix this leaky situation?

Also, my friend sold his SHO shortly after having the conversion done. I'm curious if there are still any leaks with the 'upgrade' of the system to R-134a. I've been told by multiple mechanics that Ford quick couplers on the lines are the source of most leaks. Do the replacement lines still use these couplers?

<small>[ March 08, 2002, 02:30 PM: Message edited by: fricker66 ]</small>

 

[clintonk]

Yes, the quick couplers are a common leak point, and yes, any replacement/retrofit parts use them as well. A far better design would use compression fittings that screw together, but that would take much longer to assemble at the factory. Just one more example of Ford sacrificing quality to mitigate exorbitant union labor rates.

At least make sure you have the little metal clips that snap over the A/C fittings. These help prevent movement and leaks. If the fittings start looking greasy or grimy, they're probably leaking.

Clinton Knight
'90 White 182K
'95 Green 49K

 

[89 Gary]

http://www.epa.gov/ozone/title6/609/retrguid.html#oem NOW is a good time to replace your compressor/condenser if they seem "iffy". I know that here in salt country (N.E.), my condenser was fairly rotted after 6 years,and I always rinse it and my radiator when I wash car. I believe I spent @ $1100 also which included new cond/comp. wink

 

[sprink268]

your quote of "exorbitant union labor rates" offends me. I'm sure that Ford would use the same system irregardless of any other cost or lack of there of. I'm sure corporate greed never entered your train of thought, did it?

Clay
'91 59K
lite mods

<small>[ March 09, 2002, 07:10 AM: Message edited by: sprink268 ]</small>

 

[clintonk]

That remark is bound to offend someone, and it is only my opinion, but I stand by it.

FWIW, when I lived in Atlanta, Doug Lewis converted my '90 SHO for about $1200. Later, I converted my '90 ****** myself for about $350 in parts and $350 in tools, which included a large air compressor (to run a cheap A/C venturi vacuum pump).

Having done the work myself, and being an engineer, it's clear the spring-lock couplings are a cost-saving design that's marginal at best.

Clinton Knight
'90 White 182K
'95 Green 49K

 

[89 Gary]

Originally posted by clintonk:
[QB]That remark is bound to offend someone, and it is only my opinion, but I stand by it.

Unions made this country great and they prevent/prevented management from using "Gestapo tactics". Some people don't know jack about labor history. Have you been handed everything in your life Clint? Your an Engineer "you say" yet not very smart to be offending the people who do the work and not sit behind a desk with their fake silk ties. Wise up!!!!!!!