Replacing A/C components.... need AC Tech info--UPDATE

[River Beast]

I am replacing the York in RBY's 80 W/T Laredo.... it's brand new (came with the jeep at purchase) still in the box and has the platic caps on it... I also have a new dryer... I still need to get a new schraeder valve. I am replacing all o-rings in the system as well...

My question is this... do I need to buy the oil ( lube) that goes in it or are they normally sold ready to install.. I have not looked inside the caps yet....

What else do I need to do or buy? Do the FSJ's have expansion valves?

I will be doing all the work myself and taking into the Base Auto Hobby Shop for vacumm/pressure testing prior to charging... $30 per lb for R-12 ain't cheap on a new system.

Lead me and guide me.... thanks

PS.. I may have a leaking line near the schraider valve... so this may get replaced once confirmed

Thanks for all the help in advance.

[ April 06, 2003, 08:10 AM: Message edited by: River Beast ]

[Rogue]

yes on the expansion valves - on the oil the compressor SHOULD have had directions - find out total system capacity, drain your compressor into a measuring cup note that all of the system oil does not go into the compressor put 1/2 - 1 ounce in the new dryer, put some in condensor, evaporator ETC make sure and NOT skip the vacuum step it is best to let it vacuum out all night at least a 1/2 hour minimum vacuuming removes moisture - moisture + freon = acid that eats the system from the inside out and while we're talking freon why use 12? especially at the price living in Florida A/C work makes for half my business as an Auto tech and I have converted many vehicles - I have done it by replacing everything and and I have done it by simply filling a 12 system with 134 (customer request)and have had good results with both - the only problems with conversions is the expansion valve calibration and the fact that 134 makes more head pressure requiring a more efficient condensor and or cooling fan if this compressor that came with the jeep looks pretty old you'll want to use new oil anyhow because ac oil is hygrospopic like brake fluid and will asorb moisture from the air never use an already open bottle of course plenty of people have done it without all the precautions as have I the question is how long do you want the repair to last?

[Stolen76]

I like "freeze 12" over a 134a conversion. costs the same as 134a but works better with the R12 expansion valve at lower head pressure. Be sure to coat your o-rings in oil prior to install and pull you vacuum for at least 30 minutes. I have also run r22 in an r12 system with great luck. 404a and 502 also works well, they are used in thermoking units on refer trailers as a DOT legal R12 replacement.

[gsmikie]

"freeze 12" is flamable r22 in an r12 system will freeze the compressor seals....flush the system use pag oil 8 oz o-rings for 134 evac for 30 min to 28lbs lt the vac sit for 10 min see if it leaks charge system with 2 cans of 134 let the expansion valve adj to the 134 check the charge in 24 hours add more 134 if needed

[River Beast]

Thanks for all the help and advice.... printing this out right now.....

Mikie... I may be calling you... can you hear me now?

I was told that the R134 conversion will not cool as much as R12.... is the york pleny capable of increase head pressure required by R134?

Where are the expansion valves located?

thanks again....

[Rogue]

expansion valve is in underdash unit and it doesn't adjust itself - york will be fine with 134 - i had an ol beater toyo with a 12 system that i filled with 134 and no other mods worked good but not fantastic for about a year good luck

[River Beast]

Thanks... for all the info again...

[bigblack'74]

no, the 134 sucks in the jeep i did it in the '74 waste of time..i switched back to r-12 works great..

[River Beast]

BB74,

Thats what I was thinkin.... the prehistoric systems are not edequate enuf to cool with 134... I plan on sticking with the R-12....

I just need to get all my info for Saturday's wrench session....

Anybody know the EXACT type of pag oil I need?

[BIGYELLOW78J10]

Rb, where did you get the new dryer? $$$?

I am try to decide if I sould try to pull all the parts together. I have a good compressor, I think, a couple of good evaporator deals, one set of hoses, but not condensor, mine has a hole in it from rubbing the mounts.

Would 134 be adequate to cool a J truck cab?

Thanks,

Daniel

[River Beast]

All the new parts I got came with the purchase of RBY's 80 W/T Laredo... I haven't bought a thing yet...

[CLS]

Todd,

I put 134 into my Cherokee using the conversion kit, works great, it is the coldest A/C I have ever owned. It still works great after 9-10 months, it was so cheap to do myself.

Chris

[River Beast]

CLS,

You have had no problems at all?

[Retro93]

Originally posted by River Beast:
BB74,

Thats what I was thinkin.... the prehistoric systems are not edequate enuf to cool with 134... I plan on sticking with the R-12....

I just need to get all my info for Saturday's wrench session....

Anybody know the EXACT type of pag oil I need?Todd,

R134A works just fine in the Jeep system. I converted the a/c in the '79 over, and let me tell you it gets COLD. You need to replace the drier, expansion valve and oil in the compressor [8 oz/PAG]. Other than that it pretty simple. The system holds 36 WT/OZ of R12, so use about 75% of this figure as a starting point for the -134A. If you have all the components out of the vehicle, it is also a good idea to flush them with acetone to remove all of the old system oil. smile.gif

[Allen78J20]

RB I used freeze 12 on my truck, sucked down 3 cans and it was a meat locker in there all summer. I would have the thermostat at the 1 o clock position and the fan on low after 2 minutes. No modifications etc. Easy to get.

[Green Giant]

If a 134 conversion is done "by the book" it will work fine. I have done several,2-Nissan,1-Ford,and 1- GM, all worked great. The secret is evacuating the system, even if you are just replacing components and using the same refrigerant. Go get a Haynes A/C manual, they give you the theory and the instructions for all types of systems. A/C's are like transmissions, once you know how they work, they aren't so mysterious after all.

[River Beast]

Should I have the system evacuated now before I but it open? it's empty.... will this clear/flush all the oil?

Ok... If I do the R-134....

1. 8 oz. of WHICH pag oil? Help me here...thanks

2. Replace compressor with 50% of the new PAG oil

3. Replace dryer with remaining 50% PAG oil

4. Replace all the O-rings

5. Replace schraeder valve

6. Now what all needs to be done to the expansion valve uncer the dash? Adjustment or what...

7. vacuum the system once all complete then pressure test....

8. Then what.. just fill?

[ April 03, 2003, 02:00 PM: Message edited by: River Beast ]

[Green Giant]

Yes I would evac the system 1st to get rid of any moisture and contaminants. Then again after you replace the components. (the more meticulous you are, the longer the system will last).
As for the oil, didn't the new compressor have an instruction sheet with it? It should have a chart telling you what type and how much oil. If not, I have the chart somewhere, I'll try to find it when I get home. (I'm a couple hours ahead of you, it's close to quitting time here).
Yes, you divide the total volume of oil among the different components, and you should replace all o-rings and lube them 1st.
Are you replacing the evaporator? That is where most of the contaminants end up. Most replacement compressor warranties are dependant on replacing both.

[River Beast]

I have no box with the unit... was laying in the back of the jeep in a sealed plastic bag and a tag on it.... no instructions but came with a cylindrcal canister which I believe to be a new dryer since it has plastic caps on it as well...

any info you can dig up ... I will be apreciative of..thanks

the evaporator....I may be confused here....The condensor is in front of the radiator.. on the pass side next to it is the dryer (canister)....

Where is the evaporator?

[ April 03, 2003, 02:42 PM: Message edited by: River Beast ]

[Ernzo]

Todd, I have some R12 oil that I got on Ebay, new in cans, if you need some.

I simply went R12, get it for about $25 a can /12oz on Ebay. Used Mineral oil on the O-rings. Worked great. I bought a pressure guage as well. Some of the LARGE parts stores here, Pep Boys, still have some R12 gear, not the freon, but everything else on sell down.

Luck!! AC is a modern miracle. IMHO!

[bigblack'74]

mine would get to 46 degrees with r134 and would get to 36 degrees with r12..that is a big difference to me and i used ester oil..i think that is what it is called and i just dumped some into the compressor..worked good for 2 years now..this is just what i did with a d*mn near 30 year old system..when we do ac at work all we do is evac. no other means of cleaning..it may not be the rite way but it works good for us..

[Earthmonster]

hey guys-riverbeast-
for the record I am a AC tec in Dallas,TX and have been certified for over 10 years. read; I know this stuff.
I currently have my ac system completly tore down and just had every hose replaced.
there is some good information on the board and am not arguing with anyone, but if you want your system to last, I would listen to roguestar- he knows what he is talking about.
Just a few things to add that I would consider -- A colder air temp is not always a good thing. the temprature of the air coming out of the vents for a forced air unit is by the book 10 degrees warmer than the temp of the evaporator coil. this means that if your discharge air is 36 degrees your evaporator is most probably going to turn into a block of Ice. personally I consider anything above 40 degrees to be a best bet.
If you dont know how much gas to add, you can either go by output temp like I explained, or use a sight glass-- after the bubbles go away your ok. these are less accepted than using superheat and subcooling formulas, but I think you would fall asleep if I were to explain how to do that.
Lastly, if you really want to make sure there is no moisture in your system, do what I do-- triplevac. this is a process of pulling a vacuum, breaking the vacuum with nitrogen,and repeat. the nitrogen will absorb all moisture form the system. like was said before, moisture+refrigerant=acid.
As far as using 134a, R12, R22, freeze 12, etc-- they all may work to some extent with minor mods, but I am gong to the freeze 12. I have been hearing nothing but good things about it in the industry- my supply houses say they have never heard any complaints either.
Feel free to drop me a line if you have any questions. AC stuff may not be hard to get it to work, but if you want to do it right and by the book there are lots of little tricks untrained individuals probably dont know. IE- if you convert to 134a its a good idea to add a high pressure switch to prevent damage to your compressor because of higher discharge temps. anyway, blah blah blah--- hope any of this helps.

[River Beast]

thanks for the wealth of knowledge....

the AC tech at the Auto Hobby Shop here on base ( I know him well and a good friend) says the R134 compressors reach access of 500 lbs where the York does not.... Also... the rings in the York will be eaten up by the R134...whatever he said was in it... and at best it wold work GREAT for 2 years before detioration would start hampering the sytem.

[Retro93]

So..it will keep me cool for 2 yrs. Hmmmm..sounds good to me. I really don't like the idea of getting ripped off buying R12. Talk about a scam. :rolleyes: Thanks for the info Todd.

[The BEAST]

use freeze 12 the same price as 134a with better performance in FSJ's due to york comp and serpintine r12 cond less problems colder air

[River Beast]

Well...

I got the ENTIRE AC out yestereday.... not too bad a job....

There was no sense in evac'ing the system for moisture prior to disassembly.... it was empty and he had to do it again once the system is back in anyway... to the system being opened.

I brought all the components down to the Auto Hoppy Shop to have Rich take a look.... Only one hose needs to be replaced and i have to have it made... it's the one from the site glass to the dryer on the pass side wheelwell... I wouldn't use it the way it is.. too nasty lookin...

I got all the O-rings I needed for the fittings, too... AND it was already converted to R-134... :mad:

He said since it was previously converted.... you may as well stick with the R-134 as it's VERY difficult to 100% clean the system without going all new.... so i will be sticking R134 back in it.

It did give me the oportunity to swap in the new heater box.. makes it easy with the AC out from the under the dash. AND I found some nice coolant/oil leaks once the compressor came out...

Much accomplished on a Saturady... putting it all back together today with the exception of the one new line I have towait til Monday....

Thanks for the the advice..

[ April 06, 2003, 08:12 AM: Message edited by: River Beast ]

[leila]

Silly question...where do I get Freeze 12? Do I need a license for it? How do I put in to my system? My 88 GW is not blowing cold anymore and I am not technically proficient enough to do the 134a conversion myself. Another silly question...will the Freeze 12 work in my 89 Bronco? Thanks!

[The Anti-Chrysler]

R-12 freon was used up until 1993 or 1994. 134 was only used shortly until it was reintroduced as 134a.

R-12 is not legal to sell in most states, and if it is, is very, very expensive. The average Joe cannot buy it anywhere. I have been going to someone I know at a junkyard, where they recover R-12, and recharging with that. I have seen R-134a conversions, and they are sad compared to R-12.

An '89 Bronco would use R-12 from the factory if it hasn't yet been converted.

[leila]

right, got it re the r-12, but what's the deal with this Freeze 12 stuff? Do I have to do a major conversion to use it? Is it beyond a weekend warrior or should I take it to a shop? Can I buy Freeze 12 at Pep Boys or AutoZone?

[The Anti-Chrysler]

Maybe I misunderstood the lingo. Where did you hear this name "Freeze 12"??? I assumed you were talking about R-12 freon. Let me know where I can see some info on it.

[River Beast]

Not in yet!!! Found another leaking line!!! UGH!!!!! :mad: gotta orderANOTHER custom line!!!! "#@($%*@#%*@#$)(%*#$ :mad:

More $$ in the RBY'S W/T is less $$$ for RB !!! :mad:

[Rogue]

at least its not expensive R12 leaking out ;)

LEILA - freeze12 is not availible unless you are liscensed (in most states anyway) - from what I understand freeze12 is a mixture of 134A and R22, however a 134 retrofit is really easy, you buy the fittings from the store and just screw them on, in some cases the schrader valve may need to come out depends on the manufacturer of the fittings, vacuuming the system out and charging it properly is the only thing the common person wouldn't be able to do themselves - remember an overcharged system will operate worse than an undercharged system - most shops in the area I live in will retrofit an empty system for under $75

[TexasJ10]

For what it is worth, you can get your EPA section 609 certification by taking an online 25 question open book test. This certification allows you to buy r12 at almost any auto parts store or even on line. There is a free study guide and the test is only $19.95. This certification won't make you an expert on A/C but it makes it a lot easier to buy r12 if you want to.
The test is offered by Mainstream Engineering at the following link:
http://www.epatest.com/e_609cert.html

[TexasJ10]

I have a question for the A/C techs. Is it possible for the vacuum pump oil to be sucked into the a/c system if you shut off the vacuum pump but fail to close the high and low side manifold valves? I was evacuating my A/C system and after about an hour I decided to check for leaks by shutting off the vacuum pump and checking to see if I lost vacuum. I failed to close the high and low side valves and I swear that the oil level was lower in the vacuum pump when I came back to check it.

[Rogue]

hmmm...thats a very intersting question...i'd have to say no because there is no airflow inside a vaccuum unless maybe the vacuum pump itself wasn't sealed

[TexasJ10]

Thanks RogueStar. It actually leaked down a little vacuum with the valves open, and it stopped when I closed them. I also had a little oil of some type drain from the service hoses, but I couldn't tell whether it was refrigerant oil or pump oil.

[ April 15, 2003, 07:03 AM: Message edited by: TexasJ10 ]

[leila]

Hmmmm, not sure if my system is completely dry. How can I tell? How do I get all of the r12 out before I replace it with a conversion coolant? Do auto parts stores rent vacuums for this type of job? Thanks.

[TexasJ10]

You should have your r12 professionally removed. It doesn't cost much. A lot of tool rental places have vacuum pumps, or you can get cheap venturi vacuum pumps that run off your shop air for $20 on ebay. Your shop air compressor will be running for an hour or so if you choose this route.

[JeepBountyHunter]

Can you use Freeze 12 on your already converted to 134 system??? Or do you need to get back to the R12 set up?

[leila]

ok, heres a question....based on a PITA scale vs. $$$$. What's the average cost to have an 88GW converted to 134a (or Freeze12) if all components work just no r12 left? Is it major bucks? I'm thinkin' that time=money and if the cost is under $200 thats better than screwing it up myself. Anyone know what the ballpark figure would be? I live about an hour south of DC. Thanks!

[The BEAST]

cost of converting working GW a/c system from r-12 to freeze-12(80% 134a/20% 142b)about 20 dollars .First remove all r-12 then replace fittings with freeze 12 service fittings vacume for 1 hour then charge slowly till the high side is about 60psi higher than the outside air temp and the low side at 1500 rpm is between 10 to30 psi and youir done
A web site for freeze 12 info www.technicalchemical.com (http://www.technicalchemical.com)

[seadog]

I think I will do the same.I will keep ya posted.

[seadog]

Will I also use 36oz. of freeze 12