DIY: R-12 to R-134a Conversion (How To)

suprarx7nut

YotaMD.com author
Authorized Seller
Joined
Nov 10, 2006
Messages
4,038
Likes
62
Location
Arizona
#43
My cheapy adapter leaks on the low side. New core and everything. :(

I'll be buying Toyota's $50 adapter this spring. Who thought a 1" long machkned aluminum adapter with a Schrader valve would be so hard to make well?

Sent from my Galaxy Nexus using Tapatalk 2
 

Doat

Active Member
Authorized Seller
Joined
Feb 6, 2012
Messages
2,599
Likes
0
Location
Houston, TX
#44
Alright I am finally getting around to doing the conversion and am going to take it to my mechanic to let him diagnose my system to check if I have leaks or anything, so I need to get the R134 service ports. Are these the ones I need from Advance Auto?
http://shop.advanceautoparts.com/we...r_15890308-p?navigationPath=L1*14922|L2*15017

I tried looking them up on Napa's site but not much luck unless I suck at using their site lol. I want to get them locally if possible.

Also I have a 91 MK3 can anyone tell me if one port is smaller or bigger than the other and which one? Thanks.
 

suprarx7nut

YotaMD.com author
Authorized Seller
Joined
Nov 10, 2006
Messages
4,038
Likes
62
Location
Arizona
#45
Personal experience talking here... buy the genuine Toyota service adapters and skip the advance auto ones.

Sent from my Galaxy Nexus using Tapatalk 2
 

Doat

Active Member
Authorized Seller
Joined
Feb 6, 2012
Messages
2,599
Likes
0
Location
Houston, TX
#47
Well I went to Toyota and told them what I needed and they didn't have the service ports, also on their diagram for my AC system it doesn't show the ports in the same place as they are on my car. They then told me to get it from an auto parts store.
 

JDMMA70

Active Member
Authorized Seller
Joined
Dec 4, 2006
Messages
2,667
Likes
19
Location
Houston
#48
Low Side Service Port 90 degree Adapter 88374-33040
High Side Service Port Adapter 88374-33050
 

Doat

Active Member
Authorized Seller
Joined
Feb 6, 2012
Messages
2,599
Likes
0
Location
Houston, TX
#49
Hopefully my dealer with have it thanks for the part numbers I really appreciate it. I thought the high side was better to have the 90 degree adapter? Isn't that the one on the compressor housing?

Just looked up those part numbers, $60 dollars for each valve?
 

CyFi6

Aliens.
Authorized Seller
Joined
Oct 11, 2007
Messages
2,972
Likes
2
Location
Phoenix
#50
The low side is on the compressor housing. Make sure you know exactly what you are doing and how the system works before working on it, simply opening the wrong valve could cause a can to explode and I don't need to tell you how bad that can be.
 

Doat

Active Member
Authorized Seller
Joined
Feb 6, 2012
Messages
2,599
Likes
0
Location
Houston, TX
#51
I won't be working on the system I am just getting the valves then taking it to my mechanic where he can empty out the system then properly refill it with R134 but I just want to know if those valves with those part numbers are $60 each because that can't be right.
 

CyFi6

Aliens.
Authorized Seller
Joined
Oct 11, 2007
Messages
2,972
Likes
2
Location
Phoenix
#52
Oh ok, I cant speak for the part numbers and if they are correct or not, but never underestimate Toyotas pricing :p
 

suprarx7nut

YotaMD.com author
Authorized Seller
Joined
Nov 10, 2006
Messages
4,038
Likes
62
Location
Arizona
#54
I won't be working on the system I am just getting the valves then taking it to my mechanic where he can empty out the system then properly refill it with R134 but I just want to know if those valves with those part numbers are $60 each because that can't be right.
Oh ok, I cant speak for the part numbers and if they are correct or not, but never underestimate Toyotas pricing :p
60 each is overpriced, but I'd still pay 60 each before going cheap again.

The hassle of having the cheap valves leak means you're out the cost of a new system worth of refrigerant plus labor whether its your own or a pros.

I wasted $60 on refrigerant on mine before I gave in to the fact that my brand new cheap valve was leaking. I'm sure some seal perfect, but I'd heard stories before and now I've lived through failing valves myself.

My strong suggestion is to go OEM. Champion toyota online should have more reasonable pricing.

Sent from my Galaxy Nexus using Tapatalk 2
 

Doat

Active Member
Authorized Seller
Joined
Feb 6, 2012
Messages
2,599
Likes
0
Location
Houston, TX
#55
OEM it is then, I did read some reviews on advance auto's site of people having their valves leak so screw it I'll pay extra for peace of mind.

Can you guys help guide me to finding the right parallel flow condenser? Also if I get a replacement OEM dryer from like Rockauto.com will that work fine with the R134 too?
 
Last edited:

Doat

Active Member
Authorized Seller
Joined
Feb 6, 2012
Messages
2,599
Likes
0
Location
Houston, TX
#57
Will that also fit a 91?

I checked my vales this morning and I noticed that there is a 90 degree valve on my compressor, maybe the previous owner replaced them with R134a compatible valves? I will try to contact them.
 

JDMMA70

Active Member
Authorized Seller
Joined
Dec 4, 2006
Messages
2,667
Likes
19
Location
Houston
#58
Do you want me to do the work for you? I also live in Houston Just buy the parts and pay me for the labor
 

Doat

Active Member
Authorized Seller
Joined
Feb 6, 2012
Messages
2,599
Likes
0
Location
Houston, TX
#59
I can replace the parts the only thing I won't do is refill the system lol, there is no freon in the system anyway so I am not worried about that spilling out or whatever when I replace these parts.
 

Bluechulappa

New Member
Authorized Seller
Joined
Jun 16, 2007
Messages
839
Likes
0
Location
hOUSTON
#62
I paid JDMMA70 (Derek) to fix the A/C system on my 1989 Turbo Supra this past weekend. My A/C has not functioned in several years, it's so hot and humid here in Houston, Texas I had just decided not to drive my MK3 during the summer months. I finally broke down this year and hired him to do the job after no one at Toyota and no mechanics I knew would work on the system. Let me tell you... Best investment I've done in a very long time on this vehicle! I have fallen back in love with my Supra since I can now drive it whenever I want no matter what the weather is doing here in Texas! He charges a very reasonable rate for his service and he is very profession and has all the tool for the job!

What he did:
Replaced ALL O-rings on my A/C system, Replaced the expansion valve and dryer with OEM Denso parts from Japan, he oil charged my compressor/system +dye and vacuum tested my system for over an hour with his pump. I retained my R-12 system so he charged the system with 2 cans of my freeze-12. Turns out I had some electrical issues also so he ended up fixing those as well.





In the end I have ZERO leaks in my system and it is colder than my 2010 IS350 and my 2012 FJ cruiser A/C system. That's mainly because it's still R-12! Anyways... Enough ranting I just wanted to let everyone know this guy is the real deal when it comes to fixing A/C systems! He does superior work with attention to detail and I couldn't be happier!



This is the temp coming out of my vents right after the repairs. About 45 degrees F and that is with no air to the condenser. When I drove home I froze! I'd be willing to bet it got into the upper 30's coming out of the vent! R-12 FTMFW
 

Doat

Active Member
Authorized Seller
Joined
Feb 6, 2012
Messages
2,599
Likes
0
Location
Houston, TX
#63
Now I am thinking about staying with R12 lol but R134 is so much more convenient to get. I am waiting on the rest of my parts to arrive early this week before I start replacing them then finally recharging the system. How exactly do you replace all of the O rings? Is it just for the components like the dryer, compressor, etc or is it also in the AC lines?
 

JDMMA70

Active Member
Authorized Seller
Joined
Dec 4, 2006
Messages
2,667
Likes
19
Location
Houston
#64
All the components plus the AC Lines. Personally I wouldnt stay with R12 mainly the cost, and if youre unsure if the system has issues or not. Other wise youre going to be wasting money. You can get the same performance if you get a Parallel flow condenser. I dont know how well it will work with the factory unit.
 

Doat

Active Member
Authorized Seller
Joined
Feb 6, 2012
Messages
2,599
Likes
0
Location
Houston, TX
#65
I have the parallel flow condenser sitting in my room, I replaced my fan speed resistor module, and I have the Santech green O ring kit. I am just waiting for my dryer, expansion valve, and front main seal to come in. I do want to replace everything especially the seals then take it to my mechanic to let him take care of evacuating and recharging stuff.
 

JDMMA70

Active Member
Authorized Seller
Joined
Dec 4, 2006
Messages
2,667
Likes
19
Location
Houston
#66
Yeah its not hard i replaced every seal in the guide you can follow it. Just make sure to lube the o rings.
 

57trimMKIII

Texas Supras' Slowest
Authorized Seller
Joined
Jul 14, 2010
Messages
133
Likes
0
Location
DFW, TX
#67
I dont know how well it will work with the factory unit.
My factory condenser works just fine, I did the R-134A conversion on my car 2 years ago.

However, Derek tells me I may have a bad resistor - he knows his shit when it comes to these cars!
 

CyFi6

Aliens.
Authorized Seller
Joined
Oct 11, 2007
Messages
2,972
Likes
2
Location
Phoenix
#68
Nice work man. Not sure if you mean R12 or freeze 12 Blue, they are two completely different refrigerants. Highly recommend you do some research on freeze 12 before using it, I bet if you do research it you wouldn't use it.
 

JDMMA70

Active Member
Authorized Seller
Joined
Dec 4, 2006
Messages
2,667
Likes
19
Location
Houston
#71
Nice work man. Not sure if you mean R12 or freeze 12 Blue, they are two completely different refrigerants. Highly recommend you do some research on freeze 12 before using it, I bet if you do research it you wouldn't use it.
I used Ester Oil in since its got R134 in it anyways. Shouldnt cause any issues in the future I figure from my research about it.
 

suprajztwenty

New Member
Authorized Seller
Joined
Nov 5, 2009
Messages
369
Likes
0
Location
corinth tx
#72
ill be replacing most of my system tomorrow. i think insulating the suction/low side will help with performance (condenser to dryer and dryer to evap), i found some type of insulating tape/wrap i plan to use. i dont have the extra cash for the new condenser right now so i plan on flushing it and pressure washing it out of the car to get it somewhat up to par for now...same goes for the evaporator. shooting for 40's or less out the vent when its high 90's outside.

thanks for all the tips guys, keep em coming!
 

57trimMKIII

Texas Supras' Slowest
Authorized Seller
Joined
Jul 14, 2010
Messages
133
Likes
0
Location
DFW, TX
#73
Karma (n):

Before I left work tonight, I took a pic of my climate control so I could send it to Derek saying "still blowing cold!"

I shifted into drive, and the belt started SCREAMING! Moments later the noise stopped, as I ran over something. At this point I'm thinking "great, it threw the belt." I turned the A/C off and drove home where I could access the damage. Well it turns out whenever I shifted into drive, the belt was screaming (as it was being burned away) because my compressor had locked up...

So, who else is ready for a hot summer without A/C? :sarcasm:

Unless me and the mad scientist can fix it by then, of course.
 

57trimMKIII

Texas Supras' Slowest
Authorized Seller
Joined
Jul 14, 2010
Messages
133
Likes
0
Location
DFW, TX
#78
You mean like post #73?
I wasn't around too see the first 5 years of your posts, but if they've all been like this I'm clearly not missing anything.

Those medals look nice, but "Grumpy Old Man" is the only thing I've seen. You sir, are a douche.

Now before I derail this thread any more, let's get it back on track...
 

suprarx7nut

YotaMD.com author
Authorized Seller
Joined
Nov 10, 2006
Messages
4,038
Likes
62
Location
Arizona
#79
For a "Supramania Elite," you never seem to be much help.
I appreciate the humor he brings. He gives smartass answers to dumbass questions. If you get a smartass remark it's time to re evaluate your question...

If you ask a good thorough question you're likely to get a free, expert piece of advice.

So I say douche on JJ. :)

Sent from my Galaxy Nexus using Tapatalk 2
 

Doat

Active Member
Authorized Seller
Joined
Feb 6, 2012
Messages
2,599
Likes
0
Location
Houston, TX
#80
Tomorrow I plan on installing my condenser, dryer, expansion valve, and the service port valves. Can it be done in a day?