How-to: R134a conversion

Here's some good repair guides for your Tercel :) Look here for help first!
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thebigbread
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Location: Citronelle, Al (north of mobile)

How-to: R134a conversion

Post by thebigbread »

This is a topic that has been discussed, but no one's really made a how-to guide.

Converting it to r134a is actually easier than i thought it would be. Of course youll need a r134a conversion kit, these usually include:

3 cans of r134a
R12 to r134a adapters
fill hose (some kits have a pressure gauge)
label to indicate the conversion

warning:r134a is a refrigerant. this stuff can cause frostbite or injury if you're not careful, so i recommend using gloves (leather works best) & safety goggles.

1: Evacuate all the R12. it is illegal to vent R12 into the atmosphere. most car shops will actually do it for free. If you do it yourself, evacuate both the high & low sides.

2: install the retrofit adapters. there are 2: a high side & a low side. here is a pic to help simplify things:

Image

sometimes there are 2 high side adapters in the kit. one is for 1977-on american cars, the other is for pre-1976 american cars & imports.

3: crank the engine, & set the a/c to the following:

a/c on max (press button 2 times)
recirc
fan max
cool
vent

heres a pic:

Image

4: following the kit instructions, fill the a/c with r134. if your a/c is in working order, it should engage while you are recharging it. continue to fill it to the recommended amount

tip: the tercel wagons used 1.4-1,7 lbs. of r12, most kits recommend to fill it with r134a to 70-85% of the original r12 recommendation.

5. let the engine idle for about 5 minutes to ensure the a/c is in working order.

6. if your kit supplied with it, attach the r134 conversion label.

ive heard mixed results, but mine is running at 30 degrees F.
1984 2wd wagon, "bottle rocket": http://www.myspace.com/1984tercel
1995 Isuzu TFR-S, "Shorty": no cardomain page yet
thebigbread
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Posts: 212
Joined: Fri Feb 10, 2006 7:35 pm
Location: Citronelle, Al (north of mobile)

Post by thebigbread »

a side note: do expect leaks from the fittings or lines. remember, these are 20+ year old cars. leaks are usually at a connection (or a fitting) due to a bad o-ring. a set of rings can be purchased for about $8. its generally a good idea to replace all the o-rings while you are at it.

if the a/c is still leaking, and you cant find it, i recommend a U/V leak detector kit. its simply a can of r134a with UV dye in it. it comes with a mini blacklight, and leaks will glow brightly (much easier to see at night).[/u]
1984 2wd wagon, "bottle rocket": http://www.myspace.com/1984tercel
1995 Isuzu TFR-S, "Shorty": no cardomain page yet
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ARCHINSTL
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My tercel:: Goldie is a 1986 SR5 attualmente con Weber/also owned the first T4WD in STL in late '82
Location: Kirkwood, a 'burb of St. Louis

Post by ARCHINSTL »

This is really interesting...this is ALL you did ?
And it works?
What is the kit brand and sourcing?
Pardon my naivete, but I thought the drier and some other things had to be done - and change the oil (whatever that is).
Note that I am not looking for a lesson in thermodynamics, as I have not really investigated the procedures, but from a
cursory examination, I thought the process was a LOT more involved with more parts.
This is something I would like to do next Spring.
Thanks,
Tom M.
T4WD augury?
"Oh, do not ask, 'What is it?' Let us go and make our visit."
T.S. Eliot - "The Love Song of J. Alfred Prufrock"
"Now and then we had a hope that, if we lived and were good, God would permit us to be pirates."
Mark Twain
rieseb
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Joined: Mon Jan 12, 2015 10:21 am

Conversion

Post by rieseb »

A,

I did this with mine but I completely flushed the system, changed the receiver/ Dryer, changed the expansion valve and cleaned the evaporator. After 20 years the evaporator was pretty dirty. The air blew cooler than the R-12. As they said above, change all o-rings in the system. Put the new oil into the system and then evacuate the system for a good 30 to 60 minutes. This will make sure there is no water in the system. Then fill with the R-134. While most systems try to go by pounds I slowly fill until the pressures are balanced at about 25 to 35 on the low and 225 on the high. The higher the spread the better the cooling.

A good resource website and parts place is this place in Phoenix. The web address is http://www.ackits.com.

Good luck!
Typrus
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Location: Colorado

Post by Typrus »

I just filled 134a.
Look what happened >.<
Now the question is whether the oil mixing was at fault or what....

(shrug)
RIP 10-07- 1984 Toyota Tercel SR5 4wd Wagen 6 speed

RIP 04-05- 1986 Toyota Tercel SR5 4wd Wagen 6 speed

1st Terc- 1987 Tercel SR5 4wd Wagon 6-speed, Sadly cubed

1985 Tercel Standard 4wd Wagon w/ 3-speed auto, Living a happy life in Boulder last I knew
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