R134a conversion question

[jjon90]

Just had the conversion done and wanted to know for those who did this what kind of temperature readings should I expect at the vents blowing into the passenger compartment? Thanks..

 

[rhauf]

The air should feel cool/cold... that's about as precise as it gets.

actual temperature should never be colder than about 35-40 degrees or you will risk freeze up on the evaporator (bad). the expansion valve and cut off switch prevent over-cooling if they are working properly.

other than that, fan speed, vehicle speed, outside air temperature, and humidity will all play a role in the temperature.


turn your a/c on high, then with the engine at an idle, if your compressor clutch is cycling a lot, it is likely undercharged. a fully charged system generally will not cycle the clutch at idle RPM while the a/c is working (unless its cold out maybe)

 

[Czar Zach]

How much did the conversion cost you?

 

[jjon90]

How much did the conversion cost you?

$700 new compressor, condenser, new lines and conversion kit w r134a charge + labor

 

[Jason94sport]

When it's 85 & humid I can't get lower then 47 at the vents. When it's 90+ & humid I can't get less then 51 at the vents. If it's in the 70's or not humid the lowest vent temp I have seen was 41. These are moving temps. If I sit stationary in 90 degree weather too long the vents raise to almost 60.
But my climate is pretty brutal in the summer & most of the year actually.

 

[gloomis]

$700?
Whew!

I just basically did the same thing to mine last Friday.
Used original lines and hose, condenser, and evaporator core.
New (rebuilt) compressor, accumulator/dryer, and orifice tube: $99
Can of cleaner/flush: ~$16
PAG 46 oil: (I forget - less than $10?)
And 3 cans of R134: ~$30
What is that? Around $150?
I haven't used a thermometer, but feels nice and cold to me.
And pressures looked great on gauges.

Just did about the same thing to my 94 except I had to replace the evaporator core since I couldn't get the nut broke loose between the core and the accumulator/dryer.
Finally ended up twisting the top tube in the core - I was afraid if I ever did get it loose that it would be cracked and leak.

Oh, just for those wondering, seal had failed in both compressors and all freon had leaked out. So I didn't have to get anyone to recover the freon already in the system.
Don't forget to figure that in if you're budgeting for the job.

jjon, hope it all works good for you and you end up being satisfied with it.

I know I'm spoilt - couldn't live without my AC, no matter what it cost. Just glad it's not $700.

 

[jjon90]

$700?
Whew!

I just basically did the same thing to mine last Friday.
Used original lines and hose, condenser, and evaporator core.
New (rebuilt) compressor, accumulator/dryer, and orifice tube: $99
Can of cleaner/flush: ~$16
PAG 46 oil: (I forget - less than $10?)
And 3 cans of R134: ~$30
What is that? Around $150?
I haven't used a thermometer, but feels nice and cold to me.
And pressures looked great on gauges.

Just did about the same thing to my 94 except I had to replace the evaporator core since I couldn't get the nut broke loose between the core and the accumulator/dryer.
Finally ended up twisting the top tube in the core - I was afraid if I ever did get it loose that it would be cracked and leak.

Oh, just for those wondering, seal had failed in both compressors and all freon had leaked out. So I didn't have to get anyone to recover the freon already in the system.
Don't forget to figure that in if you're budgeting for the job.

jjon, hope it all works good for you and you end up being satisfied with it.

I know I'm spoilt - couldn't live without my AC, no matter what it cost. Just glad it's not $700.

Well since I don't have A/C equipment and I do use the Explorer as a business write off ...hmm.. Let's see would I rather take a $150 deduction or a $700 one and have the day free. I just have to wait till I file my taxes to get it all back.. So in the end it cost me the interest on 700 for the time I have to wait for my refund.. Not to mention the car insurance gas and mileage write off. So basically I helped the small guy stay in business and get my money back.

 

[rhauf]

How much did the conversion cost you?

$700 new compressor, condenser, new lines and conversion kit w r134a charge + labor

i don't know how you guys managed to spend $700 on this stuff.. i just discharge the system completely (it usually already is) then i fill it with 134a. works every time.

my procedure goes something like this:

step 1. disconnect an a/c pressure line.. let all pressure out.

step 2. reconnect a/c line.

step 3. screw adaptor that comes with $5 "134a conversion kit" onto r12 fitting.

step 4. attach 134a bottle, open valve.

step 5. let engine run with a/c on until can is empty.

step 6 attach next can and repeat. do this until the compressor runs
constantly at idle.

step 7. REMOVE 134a adaptor fitting (it will leak)

step 8. drive around and feel the chill


gee that sounded more complicated than it really is... this usually takes about 15 minutes. ive done this "conversion" on at least 8 vehicles i can think of, and it's worked fine on all of them.. a few had system leaks and required another step, which was replacing all the old O-rings (you can buy an assortment box as the autoparts store for a few bux)

 

[Anime]

If you re-use the existing hoses on a 91-93 that are only for R-12, you're eventually going to lose all that R-134a through them, as the walls aren't dense enough to contain the smaller R-134a molecules. You also wind up with a contaminated system that shops will turn away if you ever have a problem since they can't evacuate it into either an R-12 or R-134a container. You can keep putting R-134a in since it's fairly cheap, of course. Just putting R-134a in an otherwise R-12 system will usually result in black death, and having to replace everything. Usually the people that cause it aren't the ones who wind up paying for the consequences, though.

 

[westfield]

700 does not seem too bad...I have a 06 Taurus and the compressor bearings are gone and now I have to replace the compressor...quotes range from 600 to 800...And no I don't have the equipment or skills to do it myself !

 

[rhauf]

If you re-use the existing hoses on a 91-93 that are only for R-12, you're eventually going to lose all that R-134a through them, as the walls aren't dense enough to contain the smaller R-134a molecules. You also wind up with a contaminated system that shops will turn away if you ever have a problem since they can't evacuate it into either an R-12 or R-134a container. You can keep putting R-134a in since it's fairly cheap, of course. Just putting R-134a in an otherwise R-12 system will usually result in black death, and having to replace everything. Usually the people that cause it aren't the ones who wind up paying for the consequences, though.

hmm, well no black death yet.. but they do tend to need recharge every so often

thanks for the tips.. that does make sense and i don't want black death.. i'll look into it a bit more.

the majority of the a/c systems i did were on old vehicles and a few of them were just junkyard parts i through together.

btw what would cause it to go into black death?

 

[jjon90]

hmm, well no black death yet.. but they do tend to need recharge every so often

thanks for the tips.. that does make sense and i don't want black death.. i'll look into it a bit more.

the majority of the a/c systems i did were on old vehicles and a few of them were just junkyard parts i through together.

btw what would cause it to go into black death?

From what I have read, the R12 oil and the 134A oil are not compatible and they form a black sludge if mixed which can clog or narrow the orifices. Please correct me if I'm wrong.

Sent from my Galaxy Nexus using Forum Runner

 

[Anime]

The sludge you mention does contribute the black goo, but there's also the issue of the compressors destroying themselves internally. The FS10, with it's multiple pistons, seems to keep going even when some of the pistons are damaged from pumping fluid (it's not designed to have fluid in it, just the refrigerant as a gas), so when you combine the two, you get black icky goo with a bunch of metal particles in it, spread everywhere in the system. That's black death. The only solution is to replace EVERYthing, since there's no cleaning it to the level an A/C system requires.

 

[bellon890]

You definitely need to change out the compressor oil if you are going to just swap refrigerants instead of mineral you need poly now for 134.

 

[bellon890]

If you do go to a auto part store ask for POE oil dont say poly(polyester) they might not know what you want.

 

[bellon890]

From what I have read, the R12 oil and the 134A oil are not compatible and they form a black sludge if mixed which can clog or narrow the orifices. Please correct me if I'm wrong.

Sent from my Galaxy Nexus using Forum Runner

You are correct one is mineral and the other is polyester.

 

[03limitedon22s]

i have changed over a few cars. all i do is take it to a shop to suck out the old r12 with a special vac (its illegal to vent in the air) for like 30 dollars. and buy a change over kit at a part store for like 30-40 bucks. if you buy a nice kit you can re-use the filler hose, gauge, and new conversion end on other cars. and they have instructions! be sure to check pressure on LOW SIDE and verify the compressor clutch will engage before you dump 10 dollar a piece cans in it.

 

[91Explored]

You might consider adding a heater bypass valve. It is purported to greatly reduce the heat and increase the cool for your AC.


http://www.explorerforum.com/forums/showthread.php?t=190431&highlight=heater+control+bypass