Supra Forums banner

1 - 20 of 44 Posts

·
Registered
Joined
·
24 Posts
Discussion Starter #1
Hey-

Summer is coming and I think it's about time to recharge my AC... I've had my MKIII for about a year.. and last summer I tried to bear with the 105+ heat out here in the desert of cali. I bought the car last year and I never got around to fixing the AC problem... I talked to the owner a long time ago and he sent me an email saying:

"the adapter fitting for r134 on the low pressure side needs to be removed and the schraeder valve needs to be removed, then you can put the r134 fitting back on and just refill the r134. "

Alright... so I looked around the forums and I guess it used to have R12 and now it's R134 cuz it's cheaper, right? So how do I do this myself? I really want to start to learn how to fix this car up (maint-wise) but I have no idea where the valves are and what not.... I looked at the TSRM but the AC section as 44 pages and I'm really lost. Could you guys help me out? Thanks
 

·
7m power
Joined
·
1,059 Posts
the low pressure fitting i think is next to the passenger side headlight.if u wanna retrofit you should start by buying the retrofit kit that they sell in the auto parts store

AC is not where u wanna start to learn how to work on cars.if i was you ill take it to a shop
 

·
92 TURBO
Joined
·
999 Posts
supraboostin said:
the low pressure fitting i think is next to the passenger side headlight.if u wanna retrofit you should start by buying the retrofit kit that they sell in the auto parts store

AC is not where u wanna start to learn how to work on cars.if i was you ill take it to a shop
The low side fitting is down on the suction line fitting at the compressor. The one that supraboostin is refering to in front of the condenser is for high pressure side.

It's not about going to autozone, buying a couple of cans of R-134a, and just dumping some refrigerant into the system as some people on this forum are probably going to tell you to do.
Since the system is empty, (low pressure switch prevents compressor clutch engagement) you probably have a leak which needs to be found and repaired so you'll need the use of an electronic leak detector that sniffs R-134a for leaks after you have pressured the system with some R-134a.
After any leaks are found and fixed, you'll then need to pull a vacuum on the system as close to 29.92"Hg as possible to remove all moisture and air from the system. For this you'll need the use of a vacuum pump specific for R-134a. Once the system is determined to be tight, meaning vacuum drops down to 29" or better on the low pressure gauge and holds for a least 30 min. with pump off, you'll than need a set of gauges specific for R-134a to properly charge the system and watch the system pressures for proper refrigerant charge and performance.
If the system has ever been open to the atmosphere for more than 20 min., you have to change out the receiver/drier tank as it will have absorbed moisture from the air into the silica gel desiccant and will end up re-releasing it thru the system causing freeze-ups at the inlet orifice inside the thermostatic expansion valve.
So bottom line is, Pay someone to do it right. You can't do this job right without the above mentioned equipment and some knowledge of a/c systems as you can possibly do damage by overcharging the system and it won't work right.
~ Mike HVAC installer and service
 

·
Registered
Joined
·
24 Posts
Discussion Starter #5
such a complex ass answer to what seemed like a simple question... but thanks. it helps a lot. to the shops to waste some more money!
 

·
Not ur jizz, not ur bizz
Joined
·
6,571 Posts
WinterWish said:
such a complex ass answer to what seemed like a simple question... but thanks. it helps a lot. to the shops to waste some more money!
its not that complicated when you aquire all the parts and lay it on the table.

get a vac pump
retrofit kit
new drier to your toyota and the proper rings that go to it.
the proper guages to fill the R134a which you can find at Home Depot and some auto part stores.

then replace drier and rings
vac the old shit out of the AC system (29-30) and hold for 30 minutes
use guages and cans of R134a to put the new shit back in.

if your ac system cant hold 29-30...then you have a leak somewhere and will definatley need to take it to someone. unless you can detect it at an easy spot and replace it.
 

·
Madd Tyte JDM yo ®
Joined
·
7,014 Posts
how much do one a dem dryer thingies cost???

my AC system has been open for over a year, so im sure ill need to replace that.

also, one of my AC lines swivels at the hardline junction near the radiator support... do they ALL do this? ive come across 3 ac lines that swivel like mine and i dont know if its normal or not.
 

·
Registered
Joined
·
6,279 Posts
davidmbedard said:
OR....

you can go with RS-23 like I have. It is a droping replacement for freon. I love it...it even will outperform 134.

David
based on what FACTS..

please don't state something as fact without backing them up with NUMBERS ;)
 

·
92 TURBO
Joined
·
999 Posts
WinterWish said:
such a complex ass answer to what seemed like a simple question... but thanks. it helps a lot. to the shops to waste some more money!
------------------------------------------------------------------------------

WinterWish said:
So how do I do this myself?
I really want to start to learn how to fix this car up (maint-wise) but I have no idea where the valves are and what not.... I looked at the TSRM but the AC section as 44 pages and I'm really lost. Could you guys help me out? Thanks
^You can't (is that better)
~mike
 

·
92 TURBO
Joined
·
999 Posts
davidmbedard said:
OR....

you can go with RS-23 like I have. It is a droping replacement for freon. I love it...it even will outperform 134.

David
^ There are NO direct "drop in" replacements for R-12.
Drop in means that it will perform exactly the same (cooling capacity & operating pressures) as the refrigerant that is being replaced with no changes in the expansion valve/orifice tube or type compressor oil that is required in the system.

~ mike
 

·
Registered
Joined
·
658 Posts
SupraMikeCT said:
^ There are NO direct "drop in" replacements for R-12.
Drop in means that it will perform exactly the same (cooling capacity & operating pressures) as the refrigerant that is being replaced with no changes in the expansion valve/orifice tube or type compressor oil that is required in the system.

~ mike
Really? I guess your an expert....

http://autorefrigerants.com/co00030.htm

Aka RS-23.

David

AND this was covered before....just do a search!
 

·
Registered
Joined
·
6,279 Posts
last time i checked... 35 degree was 35 degrees???

whe i use r-134. I always use the r-12 number of outlet temps. And everytime i am able to acheive them without issues. So how EXACTLY does Freeze-12 outperform r-134??? Cooling?? no as outlet temps are the same (35-42 degrees farenheight on a 72 degree day)
 

·
Madd Tyte JDM yo ®
Joined
·
7,014 Posts
well that sounds pretty promising... but is that the only retailer for the Freeze 12 stuff? or can we buy it some place else that doesnt require a liscense?
 

·
I heart 80's Toyota's
Joined
·
631 Posts
oh.... and stock up on the r-134... its price has doubled times 500.... a 35lb bottle was 50 bucks a year ago.... got a price of 360 today... i guess there is only one maufacture remaining...
 

·
No One Ever Listens To Me
Joined
·
5,467 Posts
flubyux2 said:
well that sounds pretty promising... but is that the only retailer for the Freeze 12 stuff? or can we buy it some place else that doesnt require a liscense?
lucky for you...im certified and licensed ;)

and for the record a pet peeve of mine...FREON is a brand name...its REFRIGERANT....that annoys the shit outta me...

also its all hype.... guess what... r-134a was made because dupont wasnt making money off of r-12 anymore...so they made upsome bullshit story about the environment... blah blah.... im sure this freeze 12 shit is the same way... it outperforms :rolleyes: based on what?

as for the question stated....i think supramikect answered it pretty well.... AC is NOT the place to start when trying to learn to work on your car...mainly because you need a lot of specialized tools to diagnose and fix...
 

·
Registered
Joined
·
658 Posts
Here is MY advice....this is what I did....follow it if you want or dont what.

1. Do NOT try and do this yourself. Call a refrigerator repair man.....thats right....a guy who will fix your fridge. Most of them work out of a truck, so he will come to you.

2. Have him discharge the system. Again, most guys wont charge you for this because in most cases they can reuse the r-12.

3. Have him recharge this system with a r-12 replacement. There are a few out there......just ask him, he will know. I have RS-23 (or 32....I forget, but def a 2 and a 3). He will also make sure that your system can hold a vaccuum. If it cant your SOL and will have to take it to a mechanic to be repaired.

4. Enjoy your cool air.

David
 

·
Not ur jizz, not ur bizz
Joined
·
6,571 Posts
IdealSupra said:
lucky for you...im certified and licensed ;)

and for the record a pet peeve of mine...FREON is a brand name...its REFRIGERANT....that annoys the shit outta me...

also its all hype.... guess what... r-134a was made because dupont wasnt making money off of r-12 anymore...so they made upsome bullshit story about the environment... blah blah.... im sure this freeze 12 shit is the same way... it outperforms :rolleyes: based on what?

as for the question stated....i think supramikect answered it pretty well.... AC is NOT the place to start when trying to learn to work on your car...mainly because you need a lot of specialized tools to diagnose and fix...
i saw no facts saying that Freeze 12 is better or as good as R12..but I will say out of personal experience that Freeze 12 does the job.

R12 is like 50 bucks a can..3hr drive to mexico and it costs me 2-3 bucks a can..depending on my negotiation skills.
 

·
92 TURBO
Joined
·
999 Posts
davidmbedard said:
Really? I guess your an expert....

http://autorefrigerants.com/co00030.htm

Aka RS-23.

David

AND this was covered before....just do a search!
--------------------------------------------------------------------------------
^ I'll REPEAT, THERE ARE NO DROP IN REPLACEMENTS FOR R-12. Because you can't seem to understand this, read below:

BTW, I went to school for HVAC for 2 years, am licensed and have my "universal refrigerant recovery" certificate which is the best of 4 levels, so I do know about refrigerants and a/c.
Check out what's in Freeze 12, is a blend of 2 existing, yes existing refrigerants, 80% R-134a & 20% HCFC-142b. Once again, It is NOT a drop in replacement for R-12 as there are NONE.


/C: NEW REFRIGERANTS

by Larry Carley, Copyright 2003 www.aa1car.com

If you’ve bought any R-12 refrigerant lately, you know it’s pretty pricey stuff. Last year, the price peaked at about $20 a pound ($600 for a 30 lb. tank) in some areas of the country. This year some predict the price could shoot as high as $30 to $33 per lb. ($1000 per tank!) if we get a long hot summer. Consequently, people are searching for less expensive alternatives to recharge their A/C systems.

NO DROP-INS

Though some alternative refrigerants are being marketed as "drop-in" replacements for R-12, there’s really no such thing. According to the EPA, the concept of a "drop-in" replacement for R-12 is a marketing myth. Such words imply a substitute refrigerant will perform the same as R-12 under all conditions, that it will require no modifications to the A/C system or changes in lubricant, and that it is compatible with R-12 and can be added to a system that still contains R-12. Federal law prohibits the topping off A/C systems with refrigerants that are different from what’s in the system—unless all of the old refrigerant is first removed so the system can be converted to a new refrigerant.

The truth is no substitute refrigerant meets all of these requirements. There are, however, a number of alternative refrigerants that have been reviewed by the EPA and have been found to meet the EPA’s SNAP (Significant New Alternatives Policy) criteria for environmental acceptability and usage. The SNAP rules prohibit flammable refrigerants or ones that contain ozone-damaging CFCs.

But just because a refrigerant meets the EPA’s usage criteria does not mean it is endorsed or "approved" by the EPA, or that it will perform well as a refrigerant.

THE ALTERNATIVES

There are currently seven alternative refrigerants from which to choose. One is R-134a, which is the only alternative currently approved by all vehicle manufacturers worldwide for new vehicles as well as for converting older R-12 applications. The OEMS say R-134a can perform well in most R-12 systems provided the proper retrofit procedures are followed. The also recommend R-134a because it is a single component refrigerant, unlike most of the alternatives which are blends of two to four ingredients.

The OEMS don’t like blends because blends can undergo "fractionation." This is when the individual ingredients in a blend separate for various reasons. Fractionation can be caused by chemical differences between the refrigerants (lighter and heavier elements don’t want to stay mixed), different rates of leakage through seals and hoses (smaller molecules leak at a higher rate than larger ones), and different rates of absorption by the compressor oil and desiccant. Fractionation is a concern because it can change the overall composition of the blend once it is in use, which can affect the performance characteristics of the refrigerant. Fractionation also makes it difficult to recycle a blended refrigerant because what comes out of the system may not be the same mix that went into the system.

The OEMS also say limiting the alternatives to one (R-134a) simplifies things, reduces the risk of cross-contamination and eliminates the need for multiple recovery machines (EPA rules require a separate dedicated recovery only or recovery/recycling machine for each type of refrigerant serviced).

BLENDS

Alternative refrigerants that have been found acceptable for automotive applications or are currently being reviewed by the EPA include the following blends:

Free Zone (RB-276). Supplied by Refrigerant Gases, this blend contains 79% R-134a, 19% HCFC-142b and 2% lubricant.
Freeze 12. Supplied by Technical Chemical, this blend contains 80% R-134a and 20% HCFC-142b.
FRIGC (FR-12). Made by Intermagnetics General and marketed by Pennzoil, this blend contains 59% R-134a, 39% HCFC-124 and 2% butane.
GHG-X4 (Autofrost & McCool Chill-It). This blend is supplied by Peoples Welding Supply and contains 51% R-22, 28.5% HCFC-124, 16.5% HCFC-142b and 4% isobutane (R-600a).
GHG-HP. Also supplied by Peoples Welding Supply, this blend contains 65% R-22, 31% HCFC-142b and 4% isobutane (R-600a).
Hot Shot\Kar Kool. Supplied by ICOR, this blend contains 50% R-22, 39% HCFC-124, 9.5% HCFC-142b and 1.5% isobutane (R-600a).
The suppliers of the alternative blends say their products typically cool better than straight R-134a in systems designed for R-12, and do not require changing the compressor oil or desiccant in some cases. Changing the desiccant to XH-7 is usually recommended if an R-12 system is converted to R-134a.

The suppliers of the alternative blends also insist the fractionation problem is exaggerated and do not foresee any major problems with recovering and recycling their products (recycling blends is currently illegal, but the EPA is reviewing its feasibility).

Are blends establishing a niche in the marketplace? One supplier of these products said they sold over a million pounds of their alternative refrigerant last year alone! Most are predicting increased sales as the price of R-12 continues to rise and stockpiles dwindle.

MACS FIELD STUDY

A field study of various refrigerants conducted by the Mobile Air Conditioning Society (MACS) compared the cooling performance of R-12, R-134a and three blended refrigerants (Freeze 12, FRIGC and McCool Chill-It). The study found that all the alternative refrigerants (including R-134a) did not cool as well as R-12 in the vehicles tested (a 1990 Pontiac Grand Am and a 1987 Honda Accord). But the study did find that the blends outperformed R-134a in the Honda (but not the Pontiac). The increase in A/C outlet temperature with the different refrigerants ranged from less than a degree to almost 11 degrees.


BOOTLEGGERS & COUNTERFEITERS

Less dangerous but equally illegal is bootleg R-12 that’s being smuggled into the U.S. from offshore. Though most of the industrialized nations have stopped manufacturing R-12 (production ended here December 31, 1995), R-12 is still being made in some Third World countries including Mexico. Some of this product is finding its way past customs in mislabeled containers or concealed in various ways. The EPA warns that much of the refrigerant it has confiscated thus far is of poor quality, contaminated by air, moisture, R-22 and other substances. The EPA has worked with customs authorities and the FBI to make a number of arrests. Fines for violating the clean air rules can run up to $25,000 per instance.

Counterfeiting branded product is another scam that’s being perpetrated to turn a fast buck in today’s market. Cylinders of counterfeit Allied Signal Genetron R-12 have reportedly been turning up in various parts of the country. The cylinders do not contain R-12 but some "unknown" refrigerant. Allied Signal says the counterfeit boxes do not have cut-outs where lot numbers strapped on cylinders would appear and there are no bar codes or white painted stripes on the sides.

CONTAMINATED REFRIGERANT

The high price of R-12 has also lead to an increase in incidences of virgin R-12 being adulterated with other less expensive refrigerants. Most technicians assume a tank of virgin refrigerant is pure, but some are finding that’s not the case. Some supplies say they now test every single tank of refrigerant to make sure it contains the proper refrigerant and that the quality of the refrigerant meets specifications.

The primary threat of contamination, though, is that of accidentally cross-contaminating refrigerants when vehicles are professionally serviced. Because the law requires all refrigerants to be recovered, there’s a potential risk of contaminating when recovery and recycling equipment is connected to a vehicle. The problem is compounded, many say, by the proliferation of alternative and illegal refrigerants.

The dangers of cross-contamination are the effects it can have on cooling performance and component reliability. R-12 and R-134a are not compatible refrigerants because R-134a will not mix with and circulate mineral-based compressor oil (which may lead to compressor failure). Nor is R-134a compatible with the moisture-absorbing desiccant XH-5, which is used in many R-12 systems.


R-134a also requires its own special type of oil: either a polyakylene (PAG) oil or a polyol ester (POE) oil. The OEMS mostly specify a variety of different PAG oils because some compressors require a heavier or lighter viscosity oil for proper lubrication (though General Motors does specify only a single grade of PAG oil for most service applications). The aftermarket generally favors POE oil because POE is compatible with both R-12 and R-134a and unlike PAG oil it will mix with mineral oil. Mineral oil, as a rule, should still be used in older R-12 systems.
 
1 - 20 of 44 Posts
Top